diff --git a/src/main/java/org/codelibs/fess/api/es/EsApiManager.java b/src/main/java/org/codelibs/fess/api/es/EsApiManager.java
index e21e0e9ea..ff624fbc6 100644
--- a/src/main/java/org/codelibs/fess/api/es/EsApiManager.java
+++ b/src/main/java/org/codelibs/fess/api/es/EsApiManager.java
@@ -179,7 +179,7 @@ public class EsApiManager extends BaseApiManager {
             } catch (final ClientAbortException e) {
                 logger.debug("Client aborts this request.", e);
             } catch (final IOException e) {
-                logger.error("Failed to read {} from {}", path, filePath);
+                logger.error("Failed to read " + path + " from " + filePath);
                 throw new WebApiException(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
             }
         } else {
@@ -189,7 +189,7 @@ public class EsApiManager extends BaseApiManager {
             } catch (final ClientAbortException e) {
                 logger.debug("Client aborts this request.", e);
             } catch (final IOException e) {
-                logger.error("Failed to read {} from {}", path, filePath);
+                logger.error("Failed to read " + path + " from " + filePath);
                 throw new WebApiException(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, e);
             }
         }
diff --git a/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java b/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java
index 36936d3a9..8c0b11ab6 100644
--- a/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java
+++ b/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java
@@ -177,7 +177,7 @@ public class JsonApiManager extends BaseJsonApiManager {
             }, OptionalThing.empty());
             response.flushBuffer();
             if (logger.isDebugEnabled()) {
-                logger.debug("Loaded {} docs", count);
+                logger.debug("Loaded " + count + " docs");
             }
         } catch (final Exception e) {
             final int status = 9;
diff --git a/src/main/java/org/codelibs/fess/app/job/AllJobScheduler.java b/src/main/java/org/codelibs/fess/app/job/AllJobScheduler.java
index e578931f1..e15e80b8d 100644
--- a/src/main/java/org/codelibs/fess/app/job/AllJobScheduler.java
+++ b/src/main/java/org/codelibs/fess/app/job/AllJobScheduler.java
@@ -89,7 +89,7 @@ public class AllJobScheduler implements LaJobScheduler {
                 try {
                     jobHelper.register(scheduledJob);
                 } catch (final Exception e) {
-                    logger.warn("Failed to update schdule {}", scheduledJob, e);
+                    logger.warn("Failed to update schdule " + scheduledJob, e);
                 }
             });
             schedulerTime = now;
diff --git a/src/main/java/org/codelibs/fess/app/job/ScriptExecutorJob.java b/src/main/java/org/codelibs/fess/app/job/ScriptExecutorJob.java
index a441b935c..1f6ed5a69 100644
--- a/src/main/java/org/codelibs/fess/app/job/ScriptExecutorJob.java
+++ b/src/main/java/org/codelibs/fess/app/job/ScriptExecutorJob.java
@@ -54,7 +54,7 @@ public class ScriptExecutorJob implements LaJob {
 
         final JobHelper jobHelper = ComponentUtil.getJobHelper();
         if (!jobHelper.isAvailable(id)) {
-            logger.info("Job {} is unavailable. Unregistering this job.", id);
+            logger.info("Job " + id + " is unavailable. Unregistering this job.");
             jobHelper.unregister(scheduledJob);
             return;
         }
@@ -70,7 +70,7 @@ public class ScriptExecutorJob implements LaJob {
 
         if (!jobManager.findJobByUniqueOf(LaJobUnique.of(id)).isPresent()) {
             if (logger.isDebugEnabled()) {
-                logger.debug("Job {} is running.", id);
+                logger.debug("Job " + id + " is running.");
             }
             return;
         }
@@ -85,13 +85,13 @@ public class ScriptExecutorJob implements LaJob {
             if (logger.isDebugEnabled()) {
                 logger.debug("Starting Job " + id + ". scriptType: " + scriptType + ", script: " + script);
             } else if (scheduledJob.isLoggingEnabled() && logger.isInfoEnabled()) {
-                logger.info("Starting Job {}.", id);
+                logger.info("Starting Job " + id + ".");
             }
 
             final Object ret = jobExecutor.execute(script);
             if (ret == null) {
                 if (scheduledJob.isLoggingEnabled() && logger.isInfoEnabled()) {
-                    logger.info("Finished Job {}.", id);
+                    logger.info("Finished Job " + id + ".");
                 }
             } else {
                 if (scheduledJob.isLoggingEnabled() && logger.isInfoEnabled()) {
@@ -109,7 +109,7 @@ public class ScriptExecutorJob implements LaJob {
                 try {
                     task.stop();
                 } catch (final Exception e) {
-                    logger.warn("Failed to stop {}", jobLog, e);
+                    logger.warn("Failed to stop " + jobLog, e);
                 }
             }
             jobLog.setEndTime(ComponentUtil.getSystemHelper().getCurrentTimeAsLong());
diff --git a/src/main/java/org/codelibs/fess/app/service/ScheduledJobService.java b/src/main/java/org/codelibs/fess/app/service/ScheduledJobService.java
index ec5fdfa1a..afa671795 100644
--- a/src/main/java/org/codelibs/fess/app/service/ScheduledJobService.java
+++ b/src/main/java/org/codelibs/fess/app/service/ScheduledJobService.java
@@ -124,7 +124,7 @@ public class ScheduledJobService {
             try {
                 ComponentUtil.getJobHelper().register(cron, scheduledJob);
             } catch (final Exception e) {
-                logger.error("Failed to start Job {}", scheduledJob.getId(), e);
+                logger.error("Failed to start Job " + scheduledJob.getId(), e);
             }
         });
     }
diff --git a/src/main/java/org/codelibs/fess/app/service/SearchLogService.java b/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
index 926852ec9..722c2043b 100644
--- a/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
+++ b/src/main/java/org/codelibs/fess/app/service/SearchLogService.java
@@ -386,7 +386,7 @@ public class SearchLogService {
                 }
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to parse {}", pager.requestedTimeRange, e);
+                    logger.debug("Failed to parse " + pager.requestedTimeRange, e);
                 }
             }
         }
@@ -411,7 +411,7 @@ public class SearchLogService {
                 }
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to parse {}", pager.requestedTimeRange, e);
+                    logger.debug("Failed to parse " + pager.requestedTimeRange, e);
                 }
             }
         }
@@ -433,7 +433,7 @@ public class SearchLogService {
                 }
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to parse {}", pager.requestedTimeRange, e);
+                    logger.debug("Failed to parse " + pager.requestedTimeRange, e);
                 }
             }
         }
@@ -458,7 +458,7 @@ public class SearchLogService {
                 }
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to parse {}", pager.requestedTimeRange, e);
+                    logger.debug("Failed to parse " + pager.requestedTimeRange, e);
                 }
             }
         }
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java b/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
index 16ab57b9e..431944421 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/backup/AdminBackupAction.java
@@ -278,7 +278,7 @@ public class AdminBackupAction extends FessAdminAction {
             });
         } catch (final Exception e) {
             if (logger.isDebugEnabled()) {
-                logger.debug("Failed to parse {}", line, e);
+                logger.debug("Failed to parse " + line, e);
             }
             return null;
         }
@@ -364,7 +364,7 @@ public class AdminBackupAction extends FessAdminAction {
                         writeCall.accept(writer);
                         writer.flush();
                     } catch (final Exception e) {
-                        logger.warn("Failed to write {} to response.", id, e);
+                        logger.warn("Failed to write " + id + " to response.", e);
                     }
                 });
     }
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/design/AdminDesignAction.java b/src/main/java/org/codelibs/fess/app/web/admin/design/AdminDesignAction.java
index 73ea87f50..ddad2b620 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/design/AdminDesignAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/design/AdminDesignAction.java
@@ -172,7 +172,7 @@ public class AdminDesignAction extends FessAdminAction {
 
         final File parentFile = uploadFile.getParentFile();
         if (!parentFile.exists() && !parentFile.mkdirs()) {
-            logger.warn("Could not create {}", parentFile.getAbsolutePath());
+            logger.warn("Could not create " + parentFile.getAbsolutePath());
         }
 
         try {
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/esreq/AdminEsreqAction.java b/src/main/java/org/codelibs/fess/app/web/admin/esreq/AdminEsreqAction.java
index be7a1d60c..ef454b3e4 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/esreq/AdminEsreqAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/esreq/AdminEsreqAction.java
@@ -88,7 +88,7 @@ public class AdminEsreqAction extends FessAdminAction {
                     CopyUtil.copy(in, tempFile);
                 } catch (final Exception e1) {
                     if (tempFile != null && tempFile.exists() && !tempFile.delete()) {
-                        logger.warn("Failed to delete {}", tempFile.getAbsolutePath());
+                        logger.warn("Failed to delete " + tempFile.getAbsolutePath());
                     }
                     throw e1;
                 }
@@ -97,7 +97,7 @@ public class AdminEsreqAction extends FessAdminAction {
                         out.write(in);
                     } finally {
                         if (tempFile.exists() && !tempFile.delete()) {
-                            logger.warn("Failed to delete {}", tempFile.getAbsolutePath());
+                            logger.warn("Failed to delete " + tempFile.getAbsolutePath());
                         }
                     }
                 });
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/group/AdminGroupAction.java b/src/main/java/org/codelibs/fess/app/web/admin/group/AdminGroupAction.java
index f3beea158..88fed0b93 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/group/AdminGroupAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/group/AdminGroupAction.java
@@ -176,7 +176,7 @@ public class AdminGroupAction extends FessAdminAction {
                         groupService.store(entity);
                         saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to add {}", entity, e);
+                        logger.error("Failed to add " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -197,7 +197,7 @@ public class AdminGroupAction extends FessAdminAction {
                         groupService.store(entity);
                         saveInfo(messages -> messages.addSuccessCrudUpdateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to update {}", entity, e);
+                        logger.error("Failed to update " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToUpdateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -221,7 +221,7 @@ public class AdminGroupAction extends FessAdminAction {
                                 groupService.delete(entity);
                                 saveInfo(messages -> messages.addSuccessCrudDeleteCrudTable(GLOBAL));
                             } catch (final Exception e) {
-                                logger.error("Failed to delete {}", entity, e);
+                                logger.error("Failed to delete " + entity, e);
                                 throwValidationError(
                                         messages -> messages.addErrorsCrudFailedToDeleteCrudTable(GLOBAL, buildThrowableMessage(e)),
                                         () -> asDetailsHtml());
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/maintenance/AdminMaintenanceAction.java b/src/main/java/org/codelibs/fess/app/web/admin/maintenance/AdminMaintenanceAction.java
index 59f4d8ff6..13bee73d9 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/maintenance/AdminMaintenanceAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/maintenance/AdminMaintenanceAction.java
@@ -113,15 +113,15 @@ public class AdminMaintenanceAction extends FessAdminAction {
                 .execute(
                         ActionListener.wrap(
                                 res -> {
-                                    logger.info("Close {}", docIndex);
+                                    logger.info("Close " + docIndex);
                                     fessEsClient
                                             .admin()
                                             .indices()
                                             .prepareOpen(docIndex)
                                             .execute(
-                                                    ActionListener.wrap(res2 -> logger.info("Open {}", docIndex),
-                                                            e -> logger.warn("Failed to open {}", docIndex, e)));
-                                }, e -> logger.warn("Failed to close {}", docIndex, e)));
+                                                    ActionListener.wrap(res2 -> logger.info("Open " + docIndex),
+                                                            e -> logger.warn("Failed to open " + docIndex, e)));
+                                }, e -> logger.warn("Failed to close " + docIndex, e)));
         saveInfo(messages -> messages.addSuccessStartedDataUpdate(GLOBAL));
         return redirect(getClass());
     }
@@ -183,7 +183,7 @@ public class AdminMaintenanceAction extends FessAdminAction {
                 CopyUtil.copy(response.getContentAsStream(), zos);
             }
         } catch (final Exception e) {
-            logger.warn("Failed to access /_{}/{}", v1, v2, e);
+            logger.warn("Failed to access /_" + v1 + "/" + v2, e);
         }
     }
 
@@ -196,7 +196,7 @@ public class AdminMaintenanceAction extends FessAdminAction {
                     CopyUtil.copy(response.getContentAsStream(), zos);
                 }
             } catch (final Exception e) {
-                logger.warn("Failed to access /_cat/{}", name, e);
+                logger.warn("Failed to access /_cat/" + name, e);
             }
         });
     }
@@ -254,7 +254,7 @@ public class AdminMaintenanceAction extends FessAdminAction {
                             logger.debug(filePath.getFileName() + ": " + len);
                         }
                     } catch (final IOException e) {
-                        logger.warn("Failed to access {}", filePath, e);
+                        logger.warn("Failed to access " + filePath, e);
                     }
                 });
             } catch (final Exception e) {
@@ -298,9 +298,9 @@ public class AdminMaintenanceAction extends FessAdminAction {
                 fessEsClient.addMapping(docIndex, "doc", toIndex);
                 fessEsClient.reindex(fromIndex, toIndex, replaceAliases);
                 if (replaceAliases && !fessEsClient.updateAlias(toIndex)) {
-                    logger.warn("Failed to update aliases for {} and {}", fromIndex, toIndex);
+                    logger.warn("Failed to update aliases for " + fromIndex + " and " + toIndex);
                 }
-            }, e -> logger.warn("Failed to reindex from {} to {}", fromIndex, toIndex, e)));
+            }, e -> logger.warn("Failed to reindex from " + fromIndex + " to " + toIndex, e)));
             return true;
         }
         saveError(messages -> messages.addErrorsFailedToReindex(GLOBAL, fromIndex, toIndex));
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/plugin/AdminPluginAction.java b/src/main/java/org/codelibs/fess/app/web/admin/plugin/AdminPluginAction.java
index 3e37e83a1..6163a79d3 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/plugin/AdminPluginAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/plugin/AdminPluginAction.java
@@ -87,7 +87,7 @@ public class AdminPluginAction extends FessAdminAction {
                 if (tempFile.exists() && !tempFile.delete()) {
                     logger.warn("Failed to delete {}.", tempFile.getAbsolutePath());
                 }
-                logger.debug("Failed to copy {}", filename, e);
+                logger.debug("Failed to copy " + filename, e);
                 throwValidationError(messages -> messages.addErrorsFailedToInstallPlugin(GLOBAL, filename), () -> asListHtml());
             }
             new Thread(() -> {
@@ -97,7 +97,7 @@ public class AdminPluginAction extends FessAdminAction {
                             pluginHelper.getArtifactFromFileName(ArtifactType.UNKNOWN, filename, tempFile.getAbsolutePath());
                     pluginHelper.installArtifact(artifact);
                 } catch (final Exception e) {
-                    logger.warn("Failed to install {}", filename, e);
+                    logger.warn("Failed to install " + filename, e);
                 } finally {
                     if (tempFile.exists() && !tempFile.delete()) {
                         logger.warn("Failed to delete {}.", tempFile.getAbsolutePath());
@@ -178,14 +178,14 @@ public class AdminPluginAction extends FessAdminAction {
             try {
                 pluginHelper.installArtifact(artifact);
             } catch (final Exception e) {
-                logger.warn("Failed to install {}", artifact.getFileName(), e);
+                logger.warn("Failed to install " + artifact.getFileName(), e);
             }
             for (final Artifact a : artifacts) {
                 if (a.getName().equals(artifact.getName()) && !a.getVersion().equals(artifact.getVersion())) {
                     try {
                         pluginHelper.deleteInstalledArtifact(a);
                     } catch (final Exception e) {
-                        logger.warn("Failed to delete {}", a.getFileName(), e);
+                        logger.warn("Failed to delete " + a.getFileName(), e);
                     }
                 }
             }
@@ -197,7 +197,7 @@ public class AdminPluginAction extends FessAdminAction {
             try {
                 ComponentUtil.getPluginHelper().deleteInstalledArtifact(artifact);
             } catch (final Exception e) {
-                logger.warn("Failed to delete {}", artifact.getFileName(), e);
+                logger.warn("Failed to delete " + artifact.getFileName(), e);
             }
         }).start();
     }
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/role/AdminRoleAction.java b/src/main/java/org/codelibs/fess/app/web/admin/role/AdminRoleAction.java
index a4d93dce2..120d226c9 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/role/AdminRoleAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/role/AdminRoleAction.java
@@ -156,7 +156,7 @@ public class AdminRoleAction extends FessAdminAction {
                         roleService.store(entity);
                         saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to add {}", entity, e);
+                        logger.error("Failed to add " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -177,7 +177,7 @@ public class AdminRoleAction extends FessAdminAction {
                 roleService.delete(entity);
                 saveInfo(messages -> messages.addSuccessCrudDeleteCrudTable(GLOBAL));
             } catch (final Exception e) {
-                logger.error("Failed to delete {}", entity, e);
+                logger.error("Failed to delete " + entity, e);
                 throwValidationError(messages -> messages.addErrorsCrudCouldNotFindCrudTable(GLOBAL, id), () -> asDetailsHtml());
             }
         }).orElse(() -> {
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/searchlist/AdminSearchlistAction.java b/src/main/java/org/codelibs/fess/app/web/admin/searchlist/AdminSearchlistAction.java
index 8cc3a125b..56d2c373f 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/searchlist/AdminSearchlistAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/searchlist/AdminSearchlistAction.java
@@ -266,7 +266,7 @@ public class AdminSearchlistAction extends FessAdminAction {
                         fessEsClient.store(index, entity);
                         saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to add {}", entity, e);
+                        logger.error("Failed to add " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -303,7 +303,7 @@ public class AdminSearchlistAction extends FessAdminAction {
                         fessEsClient.store(index, entity);
                         saveInfo(messages -> messages.addSuccessCrudUpdateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to update {}", entity, e);
+                        logger.error("Failed to update " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToUpdateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
diff --git a/src/main/java/org/codelibs/fess/app/web/admin/user/AdminUserAction.java b/src/main/java/org/codelibs/fess/app/web/admin/user/AdminUserAction.java
index e46fb57eb..843b21f82 100644
--- a/src/main/java/org/codelibs/fess/app/web/admin/user/AdminUserAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/admin/user/AdminUserAction.java
@@ -200,7 +200,7 @@ public class AdminUserAction extends FessAdminAction {
                         userService.store(entity);
                         saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to add {}", entity, e);
+                        logger.error("Failed to add " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -222,7 +222,7 @@ public class AdminUserAction extends FessAdminAction {
                         userService.store(entity);
                         saveInfo(messages -> messages.addSuccessCrudUpdateCrudTable(GLOBAL));
                     } catch (final Exception e) {
-                        logger.error("Failed to update {}", entity, e);
+                        logger.error("Failed to update " + entity, e);
                         throwValidationError(messages -> messages.addErrorsCrudFailedToUpdateCrudTable(GLOBAL, buildThrowableMessage(e)),
                                 () -> asEditHtml());
                     }
@@ -251,7 +251,7 @@ public class AdminUserAction extends FessAdminAction {
                                 userService.delete(entity);
                                 saveInfo(messages -> messages.addSuccessCrudDeleteCrudTable(GLOBAL));
                             } catch (final Exception e) {
-                                logger.error("Failed to delete {}", entity, e);
+                                logger.error("Failed to delete " + entity, e);
                                 throwValidationError(
                                         messages -> messages.addErrorsCrudFailedToDeleteCrudTable(GLOBAL, buildThrowableMessage(e)),
                                         () -> asDetailsHtml());
diff --git a/src/main/java/org/codelibs/fess/app/web/api/admin/searchlist/ApiAdminSearchlistAction.java b/src/main/java/org/codelibs/fess/app/web/api/admin/searchlist/ApiAdminSearchlistAction.java
index 141efb1ca..b2d3d525a 100644
--- a/src/main/java/org/codelibs/fess/app/web/api/admin/searchlist/ApiAdminSearchlistAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/api/admin/searchlist/ApiAdminSearchlistAction.java
@@ -133,7 +133,7 @@ public class ApiAdminSearchlistAction extends FessApiAdminAction {
                 fessEsClient.store(index, entity);
                 saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
             } catch (final Exception e) {
-                logger.error("Failed to add {}", entity, e);
+                logger.error("Failed to add " + entity, e);
                 throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)));
             }
             return entity;
@@ -174,7 +174,7 @@ public class ApiAdminSearchlistAction extends FessApiAdminAction {
                 fessEsClient.store(index, entity);
                 saveInfo(messages -> messages.addSuccessCrudUpdateCrudTable(GLOBAL));
             } catch (final Exception e) {
-                logger.error("Failed to update {}", entity, e);
+                logger.error("Failed to update " + entity, e);
                 throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToUpdateCrudTable(GLOBAL, buildThrowableMessage(e)));
             }
             return entity;
diff --git a/src/main/java/org/codelibs/fess/app/web/profile/ProfileAction.java b/src/main/java/org/codelibs/fess/app/web/profile/ProfileAction.java
index c37792b5f..d76f52f69 100644
--- a/src/main/java/org/codelibs/fess/app/web/profile/ProfileAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/profile/ProfileAction.java
@@ -70,7 +70,7 @@ public class ProfileAction extends FessSearchAction {
             userService.changePassword(username, form.newPassword);
             saveInfo(messages -> messages.addSuccessChangedPassword(GLOBAL));
         } catch (final Exception e) {
-            logger.error("Failed to change password for {}", username, e);
+            logger.error("Failed to change password for " + username, e);
             throwValidationError(messages -> messages.addErrorsFailedToChangePassword(GLOBAL), toIndexPage);
         }
         return redirect(getClass());
diff --git a/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java b/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
index 233e90345..0bd4c5568 100644
--- a/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
+++ b/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
@@ -162,7 +162,7 @@ public class FessCrawlerThread extends CrawlerThread {
                     final Date documentExpires = crawlingInfoHelper.getDocumentExpires(crawlingConfig);
                     if (documentExpires != null
                             && !indexingHelper.updateDocument(fessEsClient, id, fessConfig.getIndexFieldExpires(), documentExpires)) {
-                        logger.debug("Failed to update {} at {}", fessConfig.getIndexFieldExpires(), url);
+                        logger.debug("Failed to update " + fessConfig.getIndexFieldExpires() + " at " + url);
                     }
 
                     return false;
diff --git a/src/main/java/org/codelibs/fess/crawler/transformer/AbstractFessFileTransformer.java b/src/main/java/org/codelibs/fess/crawler/transformer/AbstractFessFileTransformer.java
index 4e6a36e54..3390d1ad8 100644
--- a/src/main/java/org/codelibs/fess/crawler/transformer/AbstractFessFileTransformer.java
+++ b/src/main/java/org/codelibs/fess/crawler/transformer/AbstractFessFileTransformer.java
@@ -154,7 +154,7 @@ public abstract class AbstractFessFileTransformer extends AbstractTransformer im
                                             if (dt != null) {
                                                 dataMap.put(mapping.getValue1(), FessFunctions.formatDate(dt));
                                             } else {
-                                                logger.warn("Failed to parse {}", mapping.toString());
+                                                logger.warn("Failed to parse " + mapping.toString());
                                             }
                                         } else {
                                             logger.warn("Unknown mapping type: {}={}", key, mapping);
diff --git a/src/main/java/org/codelibs/fess/crawler/transformer/FessXpathTransformer.java b/src/main/java/org/codelibs/fess/crawler/transformer/FessXpathTransformer.java
index a53880c19..d90468d7d 100644
--- a/src/main/java/org/codelibs/fess/crawler/transformer/FessXpathTransformer.java
+++ b/src/main/java/org/codelibs/fess/crawler/transformer/FessXpathTransformer.java
@@ -247,7 +247,7 @@ public class FessXpathTransformer extends XpathTransformer implements FessTransf
                 }
             }
         } catch (final TransformerException e) {
-            logger.warn("Could not parse a value of {}", META_NAME_ROBOTS_CONTENT, e);
+            logger.warn("Could not parse a value of " + META_NAME_ROBOTS_CONTENT, e);
         }
 
     }
@@ -593,7 +593,7 @@ public class FessXpathTransformer extends XpathTransformer implements FessTransf
                 parseTextContent(node, buf);
             }
         } catch (final Exception e) {
-            logger.warn("Could not parse a value of {}", xpath);
+            logger.warn("Could not parse a value of " + xpath);
         }
         if (buf == null) {
             return null;
@@ -694,7 +694,7 @@ public class FessXpathTransformer extends XpathTransformer implements FessTransf
                 buf.append("\n");
             }
         } catch (final Exception e) {
-            logger.warn("Could not parse a value of {}", xpath, e);
+            logger.warn("Could not parse a value of " + xpath, e);
         }
         return buf.toString().trim();
     }
@@ -854,7 +854,7 @@ public class FessXpathTransformer extends XpathTransformer implements FessTransf
                             return thumbnailUrl;
                         }
                     } catch (final Exception e) {
-                        logger.debug("Failed to parse {} at {}", imgNode, responseData.getUrl(), e);
+                        logger.debug("Failed to parse " + imgNode + " at " + responseData.getUrl(), e);
                     }
                 } else if (firstThumbnailUrl == null) {
                     firstThumbnailUrl = thumbnailUrl;
@@ -865,7 +865,7 @@ public class FessXpathTransformer extends XpathTransformer implements FessTransf
                 return firstThumbnailUrl;
             }
         } catch (final Exception e) {
-            logger.warn("Failed to retrieve thumbnail url from {}", responseData.getUrl(), e);
+            logger.warn("Failed to retrieve thumbnail url from " + responseData.getUrl(), e);
         }
         return null;
     }
diff --git a/src/main/java/org/codelibs/fess/dict/DictionaryManager.java b/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
index b30f986c7..3f8d513eb 100644
--- a/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
+++ b/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
@@ -71,7 +71,7 @@ public class DictionaryManager {
                                 }
                             }
                         } catch (final Exception e) {
-                            logger.warn("Failed to load {}", fileMap, e);
+                            logger.warn("Failed to load " + fileMap, e);
                         }
                         return null;
                     }).filter(file -> file != null).toArray(n -> new DictionaryFile<?>[n]);
diff --git a/src/main/java/org/codelibs/fess/dict/mapping/CharMappingFile.java b/src/main/java/org/codelibs/fess/dict/mapping/CharMappingFile.java
index 009acedbd..86220717d 100644
--- a/src/main/java/org/codelibs/fess/dict/mapping/CharMappingFile.java
+++ b/src/main/java/org/codelibs/fess/dict/mapping/CharMappingFile.java
@@ -152,7 +152,7 @@ public class CharMappingFile extends DictionaryFile<CharMappingItem> {
                 final Matcher m = parsePattern.matcher(replacedLine);
 
                 if (!m.find()) {
-                    logger.warn("Failed to parse {} in {}", line, path);
+                    logger.warn("Failed to parse " + line + " in " + path);
                     if (updater != null) {
                         updater.write("# " + line);
                     }
@@ -163,7 +163,7 @@ public class CharMappingFile extends DictionaryFile<CharMappingItem> {
                 output = m.group(2).trim();
 
                 if (inputs == null || output == null || inputs.length == 0) {
-                    logger.warn("Failed to parse {} in {}", line, path);
+                    logger.warn("Failed to parse " + line + " in " + path);
                     if (updater != null) {
                         updater.write("# " + line);
                     }
diff --git a/src/main/java/org/codelibs/fess/dict/stemmeroverride/StemmerOverrideFile.java b/src/main/java/org/codelibs/fess/dict/stemmeroverride/StemmerOverrideFile.java
index 588c774fa..2853b978b 100644
--- a/src/main/java/org/codelibs/fess/dict/stemmeroverride/StemmerOverrideFile.java
+++ b/src/main/java/org/codelibs/fess/dict/stemmeroverride/StemmerOverrideFile.java
@@ -149,7 +149,7 @@ public class StemmerOverrideFile extends DictionaryFile<StemmerOverrideItem> {
                 final Matcher m = parsePattern.matcher(replacedLine);
 
                 if (!m.find()) {
-                    logger.warn("Failed to parse {} in {}", line, path);
+                    logger.warn("Failed to parse " + line + " in " + path);
                     if (updater != null) {
                         updater.write("# " + line);
                     }
@@ -160,7 +160,7 @@ public class StemmerOverrideFile extends DictionaryFile<StemmerOverrideItem> {
                 final String output = m.group(2).trim();
 
                 if (input == null || output == null) {
-                    logger.warn("Failed to parse {} in {}", line, path);
+                    logger.warn("Failed to parse " + line + " in " + path);
                     if (updater != null) {
                         updater.write("# " + line);
                     }
diff --git a/src/main/java/org/codelibs/fess/ds/DataStoreFactory.java b/src/main/java/org/codelibs/fess/ds/DataStoreFactory.java
index 75966b459..bb862908b 100644
--- a/src/main/java/org/codelibs/fess/ds/DataStoreFactory.java
+++ b/src/main/java/org/codelibs/fess/ds/DataStoreFactory.java
@@ -57,7 +57,7 @@ public class DataStoreFactory {
             throw new IllegalArgumentException("name or dataStore is null.");
         }
         if (logger.isDebugEnabled()) {
-            logger.debug("Loaded {}", name);
+            logger.debug("Loaded " + name);
         }
         dataStoreMap.put(name.toLowerCase(Locale.ROOT), dataStore);
         dataStoreMap.put(dataStore.getClass().getSimpleName().toLowerCase(Locale.ROOT), dataStore);
@@ -107,7 +107,7 @@ public class DataStoreFactory {
                     }
                 }
             } catch (final Exception e) {
-                logger.warn("Failed to load {}", jarFile.getAbsolutePath(), e);
+                logger.warn("Failed to load " + jarFile.getAbsolutePath(), e);
             }
         }
         return nameSet.stream().sorted().collect(Collectors.toList());
diff --git a/src/main/java/org/codelibs/fess/ds/callback/FileListIndexUpdateCallbackImpl.java b/src/main/java/org/codelibs/fess/ds/callback/FileListIndexUpdateCallbackImpl.java
index 6121981e5..78e6f6949 100644
--- a/src/main/java/org/codelibs/fess/ds/callback/FileListIndexUpdateCallbackImpl.java
+++ b/src/main/java/org/codelibs/fess/ds/callback/FileListIndexUpdateCallbackImpl.java
@@ -191,7 +191,7 @@ public class FileListIndexUpdateCallbackImpl implements IndexUpdateCallback {
     protected boolean deleteDocument(final Map<String, String> paramMap, final Map<String, Object> dataMap) {
 
         if (logger.isDebugEnabled()) {
-            logger.debug("Deleting {}", dataMap);
+            logger.debug("Deleting " + dataMap);
         }
 
         final FessConfig fessConfig = ComponentUtil.getFessConfig();
@@ -242,7 +242,7 @@ public class FileListIndexUpdateCallbackImpl implements IndexUpdateCallback {
             indexingHelper.deleteDocumentByUrl(fessEsClient, url);
         }
         if (logger.isDebugEnabled()) {
-            logger.debug("Deleted {}", deleteUrlList);
+            logger.debug("Deleted " + deleteUrlList);
         }
         deleteUrlList.clear();
     }
diff --git a/src/main/java/org/codelibs/fess/ds/callback/IndexUpdateCallbackImpl.java b/src/main/java/org/codelibs/fess/ds/callback/IndexUpdateCallbackImpl.java
index bec761513..9644696e1 100644
--- a/src/main/java/org/codelibs/fess/ds/callback/IndexUpdateCallbackImpl.java
+++ b/src/main/java/org/codelibs/fess/ds/callback/IndexUpdateCallbackImpl.java
@@ -65,7 +65,7 @@ public class IndexUpdateCallbackImpl implements IndexUpdateCallback {
         final FessEsClient fessEsClient = ComponentUtil.getFessEsClient();
 
         if (logger.isDebugEnabled()) {
-            logger.debug("Adding {}", dataMap);
+            logger.debug("Adding " + dataMap);
         }
 
         //   required check
@@ -125,7 +125,7 @@ public class IndexUpdateCallbackImpl implements IndexUpdateCallback {
         documentSize.getAndIncrement();
 
         if (logger.isDebugEnabled()) {
-            logger.debug("The number of an added document is {}.", documentSize.get());
+            logger.debug("The number of an added document is " + documentSize.get() + ".");
         }
 
     }
diff --git a/src/main/java/org/codelibs/fess/es/client/FessEsClient.java b/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
index 3d93260f1..586a0b6a9 100644
--- a/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
+++ b/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
@@ -352,10 +352,10 @@ public class FessEsClient implements Client {
             if (response.getHttpStatusCode() == 200) {
                 return true;
             } else {
-                logger.warn("Failed to reindex from {} to {}", fromIndex, toIndex);
+                logger.warn("Failed to reindex from " + fromIndex + " to " + toIndex);
             }
         } catch (final IOException e) {
-            logger.warn("Failed to reindex from {} to {}", fromIndex, toIndex, e);
+            logger.warn("Failed to reindex from " + fromIndex + " to " + toIndex, e);
         }
         return false;
     }
@@ -389,10 +389,10 @@ public class FessEsClient implements Client {
                     client.admin().indices().prepareCreate(indexName).setSource(source, XContentType.JSON).execute()
                             .actionGet(fessConfig.getIndexIndicesTimeout());
             if (indexResponse.isAcknowledged()) {
-                logger.info("Created {} index.", indexName);
+                logger.info("Created " + indexName + " index.");
                 return true;
             } else if (logger.isDebugEnabled()) {
-                logger.debug("Failed to create {} index.", indexName);
+                logger.debug("Failed to create " + indexName + " index.");
             }
         } catch (final Exception e) {
             logger.warn(indexConfigFile + " is not found.", e);
@@ -430,7 +430,7 @@ public class FessEsClient implements Client {
                     insertBulkData(fessConfig, indexName, docType, dataPath);
                 }
             } catch (final Exception e) {
-                logger.warn("Failed to create {}/{} mapping.", indexName, docType, e);
+                logger.warn("Failed to create " + indexName + "/" + docType + " mapping.", e);
             }
         } else if (logger.isDebugEnabled()) {
             logger.debug(indexName + "/" + docType + " mapping exists.");
@@ -478,9 +478,9 @@ public class FessEsClient implements Client {
                                     client.admin().indices().prepareAliases().addAlias(createdIndexName, aliasName, source).execute()
                                             .actionGet(fessConfig.getIndexIndicesTimeout());
                             if (response.isAcknowledged()) {
-                                logger.info("Created {} alias for {}", aliasName, createdIndexName);
+                                logger.info("Created " + aliasName + " alias for " + createdIndexName);
                             } else if (logger.isDebugEnabled()) {
-                                logger.debug("Failed to create {} alias for {}", aliasName, createdIndexName);
+                                logger.debug("Failed to create " + aliasName + " alias for " + createdIndexName);
                             }
                         }));
             }
@@ -501,17 +501,17 @@ public class FessEsClient implements Client {
                         try (CurlResponse response =
                                 ComponentUtil.getCurlHelper().post("/_configsync/file").param("path", path).body(source).execute()) {
                             if (response.getHttpStatusCode() == 200) {
-                                logger.info("Register {} to {}", path, index);
+                                logger.info("Register " + path + " to " + index);
                             } else {
                                 if (response.getContentException() != null) {
-                                    logger.warn("Invalid request for {}.", path, response.getContentException());
+                                    logger.warn("Invalid request for " + path + ".", response.getContentException());
                                 } else {
-                                    logger.warn("Invalid request for {}. The response is {}", path, response.getContentAsString());
+                                    logger.warn("Invalid request for " + path + ". The response is " + response.getContentAsString());
                                 }
                             }
                         }
                     } catch (final Exception e) {
-                        logger.warn("Failed to register {}", filePath, e);
+                        logger.warn("Failed to register " + filePath, e);
                     }
                 });
         try (CurlResponse response = ComponentUtil.getCurlHelper().post("/_configsync/flush").execute()) {
@@ -559,7 +559,7 @@ public class FessEsClient implements Client {
                                 }
                             }
                         } catch (final Exception e) {
-                            logger.warn("Failed to parse {}", dataPath);
+                            logger.warn("Failed to parse " + dataPath);
                         }
                         return StringUtil.EMPTY;
                     });
diff --git a/src/main/java/org/codelibs/fess/es/config/exbhv/ScheduledJobBhv.java b/src/main/java/org/codelibs/fess/es/config/exbhv/ScheduledJobBhv.java
index a8280c2d7..625d64181 100644
--- a/src/main/java/org/codelibs/fess/es/config/exbhv/ScheduledJobBhv.java
+++ b/src/main/java/org/codelibs/fess/es/config/exbhv/ScheduledJobBhv.java
@@ -51,7 +51,7 @@ public class ScheduledJobBhv extends BsScheduledJobBhv {
                 return super.selectByPK(id);
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to select a job by {}", id, e);
+                    logger.debug("Failed to select a job by " + id, e);
                 }
                 lastException = e;
                 try {
@@ -61,7 +61,7 @@ public class ScheduledJobBhv extends BsScheduledJobBhv {
                 }
             }
         }
-        logger.warn("Failed to select a job by {}", id, lastException);
+        logger.warn("Failed to select a job by " + id, lastException);
         return OptionalEntity.empty();
     }
 }
diff --git a/src/main/java/org/codelibs/fess/es/config/exentity/DataConfig.java b/src/main/java/org/codelibs/fess/es/config/exentity/DataConfig.java
index 7ff6d3f6c..248261d21 100644
--- a/src/main/java/org/codelibs/fess/es/config/exentity/DataConfig.java
+++ b/src/main/java/org/codelibs/fess/es/config/exentity/DataConfig.java
@@ -234,7 +234,7 @@ public class DataConfig extends BsDataConfig implements CrawlingConfig {
                         try {
                             smbAuth.setPort(Integer.parseInt(port));
                         } catch (final NumberFormatException e) {
-                            logger.warn("Failed to parse {}", port, e);
+                            logger.warn("Failed to parse " + port, e);
                         }
                     }
                     smbAuth.setUsername(username);
@@ -249,7 +249,7 @@ public class DataConfig extends BsDataConfig implements CrawlingConfig {
                         try {
                             smb1Auth.setPort(Integer.parseInt(port));
                         } catch (final NumberFormatException e) {
-                            logger.warn("Failed to parse {}", port, e);
+                            logger.warn("Failed to parse " + port, e);
                         }
                     }
                     smb1Auth.setUsername(username);
@@ -272,7 +272,7 @@ public class DataConfig extends BsDataConfig implements CrawlingConfig {
                         try {
                             ftpAuth.setPort(Integer.parseInt(port));
                         } catch (final NumberFormatException e) {
-                            logger.warn("Failed to parse {}", port, e);
+                            logger.warn("Failed to parse " + port, e);
                         }
                     }
                     ftpAuth.setUsername(username);
@@ -350,7 +350,7 @@ public class DataConfig extends BsDataConfig implements CrawlingConfig {
                 try {
                     p = Integer.parseInt(port);
                 } catch (final NumberFormatException e) {
-                    logger.warn("Failed to parse {}", port, e);
+                    logger.warn("Failed to parse " + port, e);
                 }
             }
 
diff --git a/src/main/java/org/codelibs/fess/es/config/exentity/FileAuthentication.java b/src/main/java/org/codelibs/fess/es/config/exentity/FileAuthentication.java
index db717ad29..dca1febb0 100644
--- a/src/main/java/org/codelibs/fess/es/config/exentity/FileAuthentication.java
+++ b/src/main/java/org/codelibs/fess/es/config/exentity/FileAuthentication.java
@@ -54,7 +54,7 @@ public class FileAuthentication extends BsFileAuthentication {
             try {
                 fileConfig = fileConfigService.getFileConfig(getFileConfigId()).get();
             } catch (final Exception e) {
-                logger.warn("File Config {} does not exist.", getFileConfigId(), e);
+                logger.warn("File Config " + getFileConfigId() + " does not exist.", e);
             }
         }
         return fileConfig;
diff --git a/src/main/java/org/codelibs/fess/es/config/exentity/PathMapping.java b/src/main/java/org/codelibs/fess/es/config/exentity/PathMapping.java
index ad35884fe..d5535cade 100644
--- a/src/main/java/org/codelibs/fess/es/config/exentity/PathMapping.java
+++ b/src/main/java/org/codelibs/fess/es/config/exentity/PathMapping.java
@@ -69,7 +69,7 @@ public class PathMapping extends BsPathMapping {
             try {
                 return pathMapper.apply(input, matcher);
             } catch (final Exception e) {
-                logger.warn("Failed to apply {}", pathMapper, e);
+                logger.warn("Failed to apply " + pathMapper, e);
             }
         }
         return input;
diff --git a/src/main/java/org/codelibs/fess/es/config/exentity/RequestHeader.java b/src/main/java/org/codelibs/fess/es/config/exentity/RequestHeader.java
index c04efd373..a6ed792ea 100644
--- a/src/main/java/org/codelibs/fess/es/config/exentity/RequestHeader.java
+++ b/src/main/java/org/codelibs/fess/es/config/exentity/RequestHeader.java
@@ -58,7 +58,7 @@ public class RequestHeader extends BsRequestHeader {
             try {
                 webConfig = webConfigService.getWebConfig(getWebConfigId()).get();
             } catch (final Exception e) {
-                logger.warn("Web Config {} does not exist.", getWebConfigId(), e);
+                logger.warn("Web Config " + getWebConfigId() + " does not exist.", e);
             }
         }
         return webConfig;
diff --git a/src/main/java/org/codelibs/fess/es/config/exentity/WebAuthentication.java b/src/main/java/org/codelibs/fess/es/config/exentity/WebAuthentication.java
index 4ba320769..16beebe90 100644
--- a/src/main/java/org/codelibs/fess/es/config/exentity/WebAuthentication.java
+++ b/src/main/java/org/codelibs/fess/es/config/exentity/WebAuthentication.java
@@ -124,7 +124,7 @@ public class WebAuthentication extends BsWebAuthentication {
             try {
                 webConfig = webConfigService.getWebConfig(getWebConfigId()).get();
             } catch (final Exception e) {
-                logger.warn("Web Config {} does not exist.", getWebConfigId(), e);
+                logger.warn("Web Config " + getWebConfigId() + " does not exist.", e);
             }
         }
         return webConfig;
diff --git a/src/main/java/org/codelibs/fess/exec/ThumbnailGenerator.java b/src/main/java/org/codelibs/fess/exec/ThumbnailGenerator.java
index 82b7124ed..fe8c8a3c5 100644
--- a/src/main/java/org/codelibs/fess/exec/ThumbnailGenerator.java
+++ b/src/main/java/org/codelibs/fess/exec/ThumbnailGenerator.java
@@ -141,7 +141,7 @@ public class ThumbnailGenerator {
 
             final int totalCount = process(options);
             if (totalCount != 0) {
-                logger.info("Created {} thumbnail files.", totalCount);
+                logger.info("Created " + totalCount + " thumbnail files.");
             } else {
                 logger.info("No new thumbnails found.");
             }
diff --git a/src/main/java/org/codelibs/fess/helper/DataIndexHelper.java b/src/main/java/org/codelibs/fess/helper/DataIndexHelper.java
index a25fdd007..9c68951cb 100644
--- a/src/main/java/org/codelibs/fess/helper/DataIndexHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/DataIndexHelper.java
@@ -221,7 +221,7 @@ public class DataIndexHelper {
             final DataStoreFactory dataStoreFactory = ComponentUtil.getDataStoreFactory();
             dataStore = dataStoreFactory.getDataStore(dataConfig.getHandlerName());
             if (dataStore == null) {
-                logger.error("DataStore({}) is not found.", dataConfig.getHandlerName());
+                logger.error("DataStore(" + dataConfig.getHandlerName() + ") is not found.");
             } else {
                 try {
                     dataStore.store(dataConfig, indexUpdateCallback, initParamMap);
@@ -242,7 +242,7 @@ public class DataIndexHelper {
             }
             final String sessionId = initParamMap.get(Constants.SESSION_ID);
             if (StringUtil.isBlank(sessionId)) {
-                logger.warn("Invalid sessionId at {}", dataConfig);
+                logger.warn("Invalid sessionId at " + dataConfig);
                 return;
             }
             final FessConfig fessConfig = ComponentUtil.getFessConfig();
@@ -260,7 +260,7 @@ public class DataIndexHelper {
                 final long numOfDeleted = fessEsClient.deleteByQuery(index, queryBuilder);
                 logger.info("Deleted {} old docs.", numOfDeleted);
             } catch (final Exception e) {
-                logger.error("Could not delete old docs at {}", dataConfig, e);
+                logger.error("Could not delete old docs at " + dataConfig, e);
             }
         }
 
diff --git a/src/main/java/org/codelibs/fess/helper/DocumentHelper.java b/src/main/java/org/codelibs/fess/helper/DocumentHelper.java
index 3e9aadf39..dfc371b93 100644
--- a/src/main/java/org/codelibs/fess/helper/DocumentHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/DocumentHelper.java
@@ -234,7 +234,7 @@ public class DocumentHelper {
                 return ReaderUtil.readText(reader);
             } catch (final IOException e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to decode {}", hash, e);
+                    logger.debug("Failed to decode " + hash, e);
                 }
             }
         }
@@ -249,7 +249,7 @@ public class DocumentHelper {
                 }
                 return SIMILAR_DOC_HASH_PREFIX + Base64.getUrlEncoder().withoutPadding().encodeToString(baos.toByteArray());
             } catch (final IOException e) {
-                logger.warn("Failed to encode {}", hash, e);
+                logger.warn("Failed to encode " + hash, e);
             }
         }
         return hash;
diff --git a/src/main/java/org/codelibs/fess/helper/IndexingHelper.java b/src/main/java/org/codelibs/fess/helper/IndexingHelper.java
index 8049c329d..a227c8baa 100644
--- a/src/main/java/org/codelibs/fess/helper/IndexingHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/IndexingHelper.java
@@ -52,7 +52,7 @@ public class IndexingHelper {
         }
         final long execTime = System.currentTimeMillis();
         if (logger.isDebugEnabled()) {
-            logger.debug("Sending {} documents to a server.", docList.size());
+            logger.debug("Sending " + docList.size() + " documents to a server.");
         }
         try {
             if (fessConfig.isThumbnailCrawlerEnabled()) {
diff --git a/src/main/java/org/codelibs/fess/helper/JobHelper.java b/src/main/java/org/codelibs/fess/helper/JobHelper.java
index e881345f9..f027e0d0c 100644
--- a/src/main/java/org/codelibs/fess/helper/JobHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/JobHelper.java
@@ -61,7 +61,7 @@ public class JobHelper {
                 unregister(scheduledJob);
             } catch (final Exception e) {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to delete Job {}", scheduledJob, e);
+                    logger.debug("Failed to delete Job " + scheduledJob, e);
                 }
             }
             return;
@@ -73,7 +73,7 @@ public class JobHelper {
                     final Map<String, Object> params = new HashMap<>();
                     ComponentUtil.getComponent(ScheduledJobBhv.class).selectByPK(scheduledJob.getId())
                             .ifPresent(e -> params.put(Constants.SCHEDULED_JOB, e)).orElse(() -> {
-                                logger.warn("Job {} is not found.", scheduledJob.getId());
+                                logger.warn("Job " + scheduledJob.getId() + " is not found.");
                             });
                     return params;
                 };
@@ -176,7 +176,7 @@ public class JobHelper {
             if (jobLog.getEndTime() == null) {
                 jobLog.setLastUpdated(ComponentUtil.getSystemHelper().getCurrentTimeAsLong());
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Update {}", jobLog);
+                    logger.debug("Update " + jobLog);
                 }
                 ComponentUtil.getComponent(JobLogBhv.class).insertOrUpdate(jobLog, op -> {
                     op.setRefreshPolicy(Constants.TRUE);
diff --git a/src/main/java/org/codelibs/fess/helper/LabelTypeHelper.java b/src/main/java/org/codelibs/fess/helper/LabelTypeHelper.java
index c1a3bc0f3..b69f4dabf 100644
--- a/src/main/java/org/codelibs/fess/helper/LabelTypeHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/LabelTypeHelper.java
@@ -258,7 +258,7 @@ public class LabelTypeHelper {
                 if (includedPaths.matcher(path).matches()) {
                     if (excludedPaths != null && excludedPaths.matcher(path).matches()) {
                         if (logger.isDebugEnabled()) {
-                            logger.debug("Path {} matched against the excludes paths expression {}", path, excludedPaths.toString());
+                            logger.debug("Path " + path + " matched against the excludes paths expression " + excludedPaths.toString());
                         }
                         return false;
                     }
@@ -271,7 +271,7 @@ public class LabelTypeHelper {
             } else {
                 if (excludedPaths != null && excludedPaths.matcher(path).matches()) {
                     if (logger.isDebugEnabled()) {
-                        logger.debug("Path {} matched against the excludes paths expression {}", path, excludedPaths.toString());
+                        logger.debug("Path " + path + " matched against the excludes paths expression " + excludedPaths.toString());
                     }
                     return false;
                 }
diff --git a/src/main/java/org/codelibs/fess/helper/PluginHelper.java b/src/main/java/org/codelibs/fess/helper/PluginHelper.java
index e1358fdf0..c40aee625 100644
--- a/src/main/java/org/codelibs/fess/helper/PluginHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/PluginHelper.java
@@ -144,7 +144,7 @@ public class PluginHelper {
                     }
                 }
             } catch (final Exception e) {
-                logger.warn("Failed to parse {}maven-metadata.xml.", pluginUrl, e);
+                logger.warn("Failed to parse " + pluginUrl + "maven-metadata.xml.", e);
             }
         }
         return list;
@@ -182,7 +182,7 @@ public class PluginHelper {
 
     protected String getRepositoryContent(final String url) {
         if (logger.isDebugEnabled()) {
-            logger.debug("Loading {}", url);
+            logger.debug("Loading " + url);
         }
         try (final CurlResponse response = Curl.get(url).execute()) {
             return response.getContentAsString();
diff --git a/src/main/java/org/codelibs/fess/helper/ProcessHelper.java b/src/main/java/org/codelibs/fess/helper/ProcessHelper.java
index 46f7c5720..2ffc222a8 100644
--- a/src/main/java/org/codelibs/fess/helper/ProcessHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/ProcessHelper.java
@@ -47,11 +47,11 @@ public class ProcessHelper {
     public void destroy() {
         for (final String sessionId : runningProcessMap.keySet()) {
             if (logger.isInfoEnabled()) {
-                logger.info("Stopping process {}", sessionId);
+                logger.info("Stopping process " + sessionId);
             }
             if (destroyProcess(sessionId) == 0) {
                 if (logger.isInfoEnabled()) {
-                    logger.info("Stopped process {}", sessionId);
+                    logger.info("Stopped process " + sessionId);
                 }
             }
         }
diff --git a/src/main/java/org/codelibs/fess/helper/SuggestHelper.java b/src/main/java/org/codelibs/fess/helper/SuggestHelper.java
index a7c09f15a..885d9f28e 100644
--- a/src/main/java/org/codelibs/fess/helper/SuggestHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/SuggestHelper.java
@@ -110,7 +110,7 @@ public class SuggestHelper {
             try {
                 suggester.settings().array().add(SuggestSettings.DefaultKeys.SUPPORTED_FIELDS, field);
             } catch (final SuggestSettingsException e) {
-                logger.warn("Failed to add {}", field, e);
+                logger.warn("Failed to add " + field, e);
             }
         }));
         suggester.createIndexIfNothing();
diff --git a/src/main/java/org/codelibs/fess/helper/ThemeHelper.java b/src/main/java/org/codelibs/fess/helper/ThemeHelper.java
index a49b1a949..b84414f3d 100644
--- a/src/main/java/org/codelibs/fess/helper/ThemeHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/ThemeHelper.java
@@ -112,17 +112,17 @@ public class ThemeHelper {
         try (Stream<Path> walk = Files.walk(dir, FileVisitOption.FOLLOW_LINKS)) {
             walk.sorted(Comparator.reverseOrder()).forEach(f -> {
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Deleting {}", f);
+                    logger.debug("Deleting " + f);
                 }
                 try {
                     Files.delete(f);
                 } catch (final IOException e) {
-                    logger.warn("Failed to delete {}", f, e);
+                    logger.warn("Failed to delete " + f, e);
                 }
             });
             Files.deleteIfExists(dir);
         } catch (final IOException e) {
-            logger.warn("Failed to delete {}", dir, e);
+            logger.warn("Failed to delete " + dir, e);
         }
     }
 
diff --git a/src/main/java/org/codelibs/fess/helper/ViewHelper.java b/src/main/java/org/codelibs/fess/helper/ViewHelper.java
index f59a91c78..4a2fa0404 100644
--- a/src/main/java/org/codelibs/fess/helper/ViewHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/ViewHelper.java
@@ -360,7 +360,7 @@ public class ViewHelper {
                     url = URLDecoder.decode(url.replace("+", "%2B"), urlLinkEncoding);
                 } catch (final Exception e) {
                     if (logger.isDebugEnabled()) {
-                        logger.warn("Failed to decode {}", url, e);
+                        logger.warn("Failed to decode " + url, e);
                     }
                 }
             }
@@ -675,7 +675,7 @@ public class ViewHelper {
                 CloseableUtil.closeQuietly(responseData);
             }
             if (logger.isDebugEnabled()) {
-                logger.debug("Finished to write {}", url);
+                logger.debug("Finished to write " + url);
             }
         });
         return response;
diff --git a/src/main/java/org/codelibs/fess/helper/WebFsIndexHelper.java b/src/main/java/org/codelibs/fess/helper/WebFsIndexHelper.java
index 8a73527ea..059d385f4 100644
--- a/src/main/java/org/codelibs/fess/helper/WebFsIndexHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/WebFsIndexHelper.java
@@ -143,7 +143,7 @@ public class WebFsIndexHelper {
                 try {
                     urlFilterService.delete(sid);
                 } catch (final Exception e) {
-                    logger.warn("Failed to delete url filters for {}", sid);
+                    logger.warn("Failed to delete url filters for " + sid);
                 }
             }
 
@@ -195,7 +195,7 @@ public class WebFsIndexHelper {
             }
 
             if (logger.isDebugEnabled()) {
-                logger.debug("Crawling {}", urlsStr);
+                logger.debug("Crawling " + urlsStr);
             }
 
             crawler.setBackground(true);
@@ -251,7 +251,7 @@ public class WebFsIndexHelper {
                 try {
                     urlFilterService.delete(sid);
                 } catch (final Exception e) {
-                    logger.warn("Failed to delete url filters for {}", sid);
+                    logger.warn("Failed to delete url filters for " + sid);
                 }
             }
 
@@ -330,7 +330,7 @@ public class WebFsIndexHelper {
             }
 
             if (logger.isDebugEnabled()) {
-                logger.debug("Crawling {}", pathsStr);
+                logger.debug("Crawling " + pathsStr);
             }
 
             crawler.setBackground(true);
@@ -465,7 +465,7 @@ public class WebFsIndexHelper {
             // clear url filter
             urlFilterService.delete(sid);
         } catch (final Exception e) {
-            logger.warn("Failed to delete UrlFilter for {}", sid, e);
+            logger.warn("Failed to delete UrlFilter for " + sid, e);
         }
 
         try {
@@ -473,14 +473,14 @@ public class WebFsIndexHelper {
             urlQueueService.clearCache();
             urlQueueService.delete(sid);
         } catch (final Exception e) {
-            logger.warn("Failed to delete UrlQueue for {}", sid, e);
+            logger.warn("Failed to delete UrlQueue for " + sid, e);
         }
 
         try {
             // clear
             dataService.delete(sid);
         } catch (final Exception e) {
-            logger.warn("Failed to delete AccessResult for {}", sid, e);
+            logger.warn("Failed to delete AccessResult for " + sid, e);
         }
     }
 
diff --git a/src/main/java/org/codelibs/fess/indexer/IndexUpdater.java b/src/main/java/org/codelibs/fess/indexer/IndexUpdater.java
index 5a9d508bd..533a70ebb 100644
--- a/src/main/java/org/codelibs/fess/indexer/IndexUpdater.java
+++ b/src/main/java/org/codelibs/fess/indexer/IndexUpdater.java
@@ -252,7 +252,7 @@ public class IndexUpdater extends Thread {
                         throw e;
                     }
                     errorCount++;
-                    logger.warn("Failed to access data. Retry to access.. {}", errorCount, e);
+                    logger.warn("Failed to access data. Retry to access.. " + errorCount, e);
                 } finally {
                     if (systemHelper.isForceStop()) {
                         finishCrawling = true;
@@ -318,7 +318,7 @@ public class IndexUpdater extends Thread {
         final long maxDocumentRequestSize = fessConfig.getIndexerWebfsMaxDocumentRequestSizeAsInteger().longValue();
         for (final EsAccessResult accessResult : arList) {
             if (logger.isDebugEnabled()) {
-                logger.debug("Indexing {}", accessResult.getUrl());
+                logger.debug("Indexing " + accessResult.getUrl());
             }
             accessResult.setStatus(Constants.DONE_STATUS);
             accessResultList.add(accessResult);
@@ -326,7 +326,7 @@ public class IndexUpdater extends Thread {
             if (accessResult.getHttpStatusCode() != 200) {
                 // invalid page
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Skipped. The response code is {}.", accessResult.getHttpStatusCode());
+                    logger.debug("Skipped. The response code is " + accessResult.getHttpStatusCode() + ".");
                 }
                 continue;
             }
@@ -379,7 +379,7 @@ public class IndexUpdater extends Thread {
                     }
                     documentSize++;
                     if (logger.isDebugEnabled()) {
-                        logger.debug("The number of an added document is {}.", documentSize);
+                        logger.debug("The number of an added document is " + documentSize + ".");
                     }
                 } catch (final Exception e) {
                     logger.warn("Could not add a doc: " + accessResult.getUrl(), e);
@@ -427,7 +427,7 @@ public class IndexUpdater extends Thread {
         final FessConfig fessConfig = ComponentUtil.getFessConfig();
         map.put(fessConfig.getIndexFieldBoost(), documentBoost);
         if (logger.isDebugEnabled()) {
-            logger.debug("Set a document boost ({}).", documentBoost);
+            logger.debug("Set a document boost (" + documentBoost + ").");
         }
     }
 
@@ -465,7 +465,7 @@ public class IndexUpdater extends Thread {
             accessResultList.clear();
             final long time = System.currentTimeMillis() - execTime;
             if (logger.isDebugEnabled()) {
-                logger.debug("Updated {} access results. The execution time is {}ms.", size, time);
+                logger.debug("Updated " + size + " access results. The execution time is " + time + "ms.");
             }
             return time;
         }
diff --git a/src/main/java/org/codelibs/fess/job/UpdateLabelJob.java b/src/main/java/org/codelibs/fess/job/UpdateLabelJob.java
index 573a81f79..b7deef2af 100644
--- a/src/main/java/org/codelibs/fess/job/UpdateLabelJob.java
+++ b/src/main/java/org/codelibs/fess/job/UpdateLabelJob.java
@@ -63,7 +63,7 @@ public class UpdateLabelJob {
                                                 .field(fessConfig.getIndexFieldLabel(), labelSet.toArray(n -> new String[n])).endObject());
                                     }
                                 } catch (final IOException e) {
-                                    logger.warn("Failed to process {}", hit, e);
+                                    logger.warn("Failed to process " + hit, e);
                                 }
                                 return null;
                             });
diff --git a/src/main/java/org/codelibs/fess/mylasta/direction/sponsor/FessUserLocaleProcessProvider.java b/src/main/java/org/codelibs/fess/mylasta/direction/sponsor/FessUserLocaleProcessProvider.java
index 9bb016277..4ed0c5307 100644
--- a/src/main/java/org/codelibs/fess/mylasta/direction/sponsor/FessUserLocaleProcessProvider.java
+++ b/src/main/java/org/codelibs/fess/mylasta/direction/sponsor/FessUserLocaleProcessProvider.java
@@ -49,7 +49,7 @@ public class FessUserLocaleProcessProvider implements UserLocaleProcessProvider
             try {
                 return requestManager.getParameter(name).filter(StringUtil::isNotBlank).map(LocaleUtils::toLocale);
             } catch (final Exception e) {
-                logger.debug("Failed to parse a value of {}.", name, e);
+                logger.debug("Failed to parse a value of " + name + ".", e);
             }
         }
         return OptionalObject.empty();
diff --git a/src/main/java/org/codelibs/fess/sso/spnego/SpnegoAuthenticator.java b/src/main/java/org/codelibs/fess/sso/spnego/SpnegoAuthenticator.java
index 00db34cf3..48c613d8c 100644
--- a/src/main/java/org/codelibs/fess/sso/spnego/SpnegoAuthenticator.java
+++ b/src/main/java/org/codelibs/fess/sso/spnego/SpnegoAuthenticator.java
@@ -135,7 +135,7 @@ public class SpnegoAuthenticator implements SsoAuthenticator {
                     }
 
                     if (logger.isDebugEnabled()) {
-                        logger.debug("principal={}", principal);
+                        logger.debug("principal=" + principal);
                     }
 
                     final String[] username = principal.getName().split("@", 2);
diff --git a/src/main/java/org/codelibs/fess/taglib/FessFunctions.java b/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
index 9fbd023a6..dcf2e82c6 100644
--- a/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
+++ b/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
@@ -82,7 +82,7 @@ public class FessFunctions {
                             return Files.getLastModifiedTime(path).toMillis();
                         }
                     } catch (final Exception e) {
-                        logger.debug("Failed to access {}", key, e);
+                        logger.debug("Failed to access " + key, e);
                     }
                     return 0L;
                 }
@@ -328,7 +328,7 @@ public class FessFunctions {
                     sb.append("?t=").append(value.toString());
                 }
             } catch (final ExecutionException e) {
-                logger.debug("Failed to access {}", input, e);
+                logger.debug("Failed to access " + input, e);
             }
         }
         return LaResponseUtil.getResponse().encodeURL(sb.toString());
diff --git a/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java b/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
index 48f05e38e..6705e05d0 100644
--- a/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
+++ b/src/main/java/org/codelibs/fess/thumbnail/ThumbnailManager.java
@@ -188,7 +188,7 @@ public class ThumbnailManager {
         });
         taskList.clear();
         if (logger.isDebugEnabled()) {
-            logger.debug("Storing {} thumbnail tasks.", list.size());
+            logger.debug("Storing " + list.size() + " thumbnail tasks.");
         }
         final ThumbnailQueueBhv thumbnailQueueBhv = ComponentUtil.getComponent(ThumbnailQueueBhv.class);
         thumbnailQueueBhv.batchInsert(list);
@@ -243,7 +243,7 @@ public class ThumbnailManager {
             final File noImageFile = new File(outputFile.getAbsolutePath() + NOIMAGE_FILE_SUFFIX);
             if (!noImageFile.isFile() || System.currentTimeMillis() - noImageFile.lastModified() > noImageExpired) {
                 if (noImageFile.isFile() && !noImageFile.delete()) {
-                    logger.warn("Failed to delete {}", noImageFile.getAbsolutePath());
+                    logger.warn("Failed to delete " + noImageFile.getAbsolutePath());
                 }
                 final ThumbnailGenerator generator = ComponentUtil.getComponent(generatorName);
                 if (generator.isAvailable()) {
@@ -262,7 +262,7 @@ public class ThumbnailManager {
                 logger.debug("No image file exists: " + noImageFile.getAbsolutePath());
             }
         } catch (final Exception e) {
-            logger.warn("Failed to create thumbnail for {}", entity, e);
+            logger.warn("Failed to create thumbnail for " + entity, e);
         }
     }
 
@@ -407,7 +407,7 @@ public class ThumbnailManager {
             try {
                 Files.delete(path);
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Delete {}", path);
+                    logger.debug("Delete " + path);
                 }
 
                 Path parent = path.getParent();
@@ -415,7 +415,7 @@ public class ThumbnailManager {
                     parent = parent.getParent();
                 }
             } catch (final IOException e) {
-                logger.warn("Failed to delete {}", path, e);
+                logger.warn("Failed to delete " + path, e);
             }
         }
 
@@ -455,7 +455,7 @@ public class ThumbnailManager {
         @Override
         public FileVisitResult visitFileFailed(final Path file, final IOException e) throws IOException {
             if (e != null) {
-                logger.warn("I/O exception on {}", file, e);
+                logger.warn("I/O exception on " + file, e);
             }
             return FileVisitResult.CONTINUE;
         }
@@ -463,7 +463,7 @@ public class ThumbnailManager {
         @Override
         public FileVisitResult postVisitDirectory(final Path dir, final IOException e) throws IOException {
             if (e != null) {
-                logger.warn("I/O exception on {}", dir, e);
+                logger.warn("I/O exception on " + dir, e);
             }
             deleteEmptyDirectory(dir);
             return FileVisitResult.CONTINUE;
@@ -477,7 +477,7 @@ public class ThumbnailManager {
             if (directory.list() != null && directory.list().length == 0 && !THUMBNAILS_DIR_NAME.equals(directory.getName())) {
                 Files.delete(dir);
                 if (logger.isDebugEnabled()) {
-                    logger.debug("Delete {}", dir);
+                    logger.debug("Delete " + dir);
                 }
                 return true;
             }
@@ -504,9 +504,9 @@ public class ThumbnailManager {
                                 // ignore
                     }
                     Files.move(path, newPath);
-                    logger.info("Move {} to {}", path, newPath);
+                    logger.info("Move " + path + " to " + newPath);
                 } catch (final IOException e) {
-                    logger.warn("Failed to move {}", path, e);
+                    logger.warn("Failed to move " + path, e);
                 }
             }
         }       );
diff --git a/src/main/java/org/codelibs/fess/thumbnail/impl/BaseThumbnailGenerator.java b/src/main/java/org/codelibs/fess/thumbnail/impl/BaseThumbnailGenerator.java
index 4770013ea..d2d01f342 100644
--- a/src/main/java/org/codelibs/fess/thumbnail/impl/BaseThumbnailGenerator.java
+++ b/src/main/java/org/codelibs/fess/thumbnail/impl/BaseThumbnailGenerator.java
@@ -154,7 +154,7 @@ public abstract class BaseThumbnailGenerator implements ThumbnailGenerator {
             ComponentUtil.getIndexingHelper().updateDocument(ComponentUtil.getFessEsClient(), thumbnailId,
                     fessConfig.getIndexFieldThumbnail(), value);
         } catch (final Exception e) {
-            logger.warn("Failed to update thumbnail field at {}", thumbnailId, e);
+            logger.warn("Failed to update thumbnail field at " + thumbnailId, e);
         }
     }
 
@@ -182,10 +182,10 @@ public abstract class BaseThumbnailGenerator implements ThumbnailGenerator {
             if (e.getCause() == null) {
                 logger.debug(e.getMessage());
             } else {
-                logger.warn("Failed to process {}", id, e);
+                logger.warn("Failed to process " + id, e);
             }
         } catch (final Exception e) {
-            logger.warn("Failed to process {}", id, e);
+            logger.warn("Failed to process " + id, e);
         }
         return false;
     }
diff --git a/src/main/java/org/codelibs/fess/thumbnail/impl/CommandGenerator.java b/src/main/java/org/codelibs/fess/thumbnail/impl/CommandGenerator.java
index 5d6107e16..3f4885a2f 100644
--- a/src/main/java/org/codelibs/fess/thumbnail/impl/CommandGenerator.java
+++ b/src/main/java/org/codelibs/fess/thumbnail/impl/CommandGenerator.java
@@ -101,7 +101,7 @@ public class CommandGenerator extends BaseThumbnailGenerator {
                 executeCommand(thumbnailId, cmdList);
 
                 if (outputFile.isFile() && outputFile.length() == 0) {
-                    logger.warn("Thumbnail File is empty. ID is {}", thumbnailId);
+                    logger.warn("Thumbnail File is empty. ID is " + thumbnailId);
                     if (outputFile.delete()) {
                         logger.info("Deleted: " + outputFile.getAbsolutePath());
                     }
@@ -119,7 +119,7 @@ public class CommandGenerator extends BaseThumbnailGenerator {
                 return false;
             } finally {
                 if (tempFile != null && !tempFile.delete()) {
-                    logger.debug("Failed to delete {}", tempFile.getAbsolutePath());
+                    logger.debug("Failed to delete " + tempFile.getAbsolutePath());
                 }
             }
         });
@@ -164,7 +164,7 @@ public class CommandGenerator extends BaseThumbnailGenerator {
                 p.destroy();
             }
         } catch (final Exception e) {
-            logger.warn("Failed to generate a thumbnail of {}", thumbnailId, e);
+            logger.warn("Failed to generate a thumbnail of " + thumbnailId, e);
         }
         if (task != null) {
             task.cancel();
diff --git a/src/main/java/org/codelibs/fess/thumbnail/impl/HtmlTagBasedGenerator.java b/src/main/java/org/codelibs/fess/thumbnail/impl/HtmlTagBasedGenerator.java
index 45ff733e8..e88659e55 100644
--- a/src/main/java/org/codelibs/fess/thumbnail/impl/HtmlTagBasedGenerator.java
+++ b/src/main/java/org/codelibs/fess/thumbnail/impl/HtmlTagBasedGenerator.java
@@ -120,7 +120,7 @@ public class HtmlTagBasedGenerator extends BaseThumbnailGenerator {
                         if (!created) {
                             updateThumbnailField(thumbnailId, StringUtil.EMPTY);
                             if (outputFile.exists() && !outputFile.delete()) {
-                                logger.warn("Failed to delete {}", outputFile.getAbsolutePath());
+                                logger.warn("Failed to delete " + outputFile.getAbsolutePath());
                             }
                         }
                     }
diff --git a/src/main/java/org/codelibs/fess/util/GroovyUtil.java b/src/main/java/org/codelibs/fess/util/GroovyUtil.java
index 0beeb60bb..1ee3d3ed5 100644
--- a/src/main/java/org/codelibs/fess/util/GroovyUtil.java
+++ b/src/main/java/org/codelibs/fess/util/GroovyUtil.java
@@ -48,7 +48,7 @@ public final class GroovyUtil {
             //                try {
             //                    GroovySystem.getMetaClassRegistry().removeMetaClass(c);
             //                } catch (Throwable t) {
-            //                    logger.warn("Failed to delete {}", c, t);
+            //                    logger.warn("Failed to delete " + c, t);
             //                }
             //            });
             loader.clearCache();
diff --git a/src/main/java/org/codelibs/fess/util/ThreadDumpUtil.java b/src/main/java/org/codelibs/fess/util/ThreadDumpUtil.java
index d6099088f..9ab3a7e04 100644
--- a/src/main/java/org/codelibs/fess/util/ThreadDumpUtil.java
+++ b/src/main/java/org/codelibs/fess/util/ThreadDumpUtil.java
@@ -58,7 +58,7 @@ public class ThreadDumpUtil {
                 }
             });
         } catch (final Exception e) {
-            logger.warn("Failed to write a thread dump to {}", file, e);
+            logger.warn("Failed to write a thread dump to " + file, e);
         }
     }
 
diff --git a/src/main/java/org/codelibs/fess/util/UpgradeUtil.java b/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
index dbf31cb97..aa0f8ca3d 100644
--- a/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
+++ b/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
@@ -50,14 +50,14 @@ public final class UpgradeUtil {
             final String source = FileUtil.readUTF8(filePath);
             try (CurlResponse response = ComponentUtil.getCurlHelper().post("/_configsync/file").param("path", path).body(source).execute()) {
                 if (response.getHttpStatusCode() == 200) {
-                    logger.info("Register {} to {}", path, indexName);
+                    logger.info("Register " + path + " to " + indexName);
                     return true;
                 } else {
-                    logger.warn("Invalid request for {}", path);
+                    logger.warn("Invalid request for " + path);
                 }
             }
         } catch (final Exception e) {
-            logger.warn("Failed to register {}", filePath, e);
+            logger.warn("Failed to register " + filePath, e);
         }
         return false;
     }
@@ -74,10 +74,10 @@ public final class UpgradeUtil {
                         indicesClient.prepareAliases().addAlias(indexName, aliasName, source).execute()
                                 .actionGet(fessConfig.getIndexIndicesTimeout());
                 if (response.isAcknowledged()) {
-                    logger.info("Created {} alias for {}", aliasName, indexName);
+                    logger.info("Created " + aliasName + " alias for " + indexName);
                     return true;
                 } else if (logger.isDebugEnabled()) {
-                    logger.debug("Failed to create {} alias for {}", aliasName, indexName);
+                    logger.debug("Failed to create " + aliasName + " alias for " + indexName);
                 }
             }
         } catch (final ResourceNotFoundRuntimeException e) {
@@ -114,7 +114,7 @@ public final class UpgradeUtil {
                 }
                 // TODO bulk
             } catch (final Exception e) {
-                logger.warn("Failed to create {}/{} mapping.", index, type, e);
+                logger.warn("Failed to create " + index + "/" + type + " mapping.", e);
             }
         }
         return false;
@@ -150,12 +150,12 @@ public final class UpgradeUtil {
             final PutMappingRequestBuilder builder = indicesClient.preparePutMapping(index).setSource(source, XContentType.JSON);
             final AcknowledgedResponse pmResponse = builder.execute().actionGet();
             if (!pmResponse.isAcknowledged()) {
-                logger.warn("Failed to update {} settings.", index);
+                logger.warn("Failed to update " + index + " settings.");
             } else {
                 return true;
             }
         } catch (final Exception e) {
-            logger.warn("Failed to update {} settings.", index, e);
+            logger.warn("Failed to update " + index + " settings.", e);
         }
 
         return false;
@@ -167,7 +167,7 @@ public final class UpgradeUtil {
             fessEsClient.index(indexRequest).actionGet();
             return true;
         } catch (final Exception e) {
-            logger.warn("Failed to add {} to {}", id, index, e);
+            logger.warn("Failed to add " + id + " to " + index, e);
         }
         return false;
     }
@@ -191,13 +191,13 @@ public final class UpgradeUtil {
 
             @Override
             public void onResponse(final AcknowledgedResponse response) {
-                logger.info("Deleted {} index.", index);
+                logger.info("Deleted " + index + " index.");
                 comsumer.accept(response);
             }
 
             @Override
             public void onFailure(final Exception e) {
-                logger.warn("Failed to delete {} index.", index, e);
+                logger.warn("Failed to delete " + index + " index.", e);
             }
         });
     }