diff --git a/dbflute.xml b/dbflute.xml
index e33b2e784..75556ae0f 100644
--- a/dbflute.xml
+++ b/dbflute.xml
@@ -2,7 +2,7 @@
 <project name="dbflute" basedir=".">
 	<property name="mydbflute.dir" value="${basedir}/mydbflute" />
 	<property name="target.dir" value="${basedir}/target" />
-	<property name="branch.name" value="master" />
+	<property name="branch.name" value="es-6.3" />
 	<property name="mydbflute.url" value="https://github.com/lastaflute/lastaflute-example-waterfront/archive/${branch.name}.zip" />
 
 	<target name="mydbflute.check">
diff --git a/plugin.xml b/plugin.xml
index 01d989ad1..7cd941259 100644
--- a/plugin.xml
+++ b/plugin.xml
@@ -13,66 +13,66 @@
 		<mkdir dir="${plugins.dir}" />
 		<!-- analysis-fess -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="analysis-fess" />
-			<param name="plugin.version" value="6.2.1" />
-			<param name="plugin.zip.version" value="6.2.1" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180614.205104-1" />
 		</antcall>
 		<!-- analysis-ja -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="analysis-ja" />
-			<param name="plugin.version" value="6.2.1" />
-			<param name="plugin.zip.version" value="6.2.1" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180614.213049-1" />
 		</antcall>
 		<!-- analysis-synonym -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="analysis-synonym" />
-			<param name="plugin.version" value="6.2.1" />
-			<param name="plugin.zip.version" value="6.2.1" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180614.214213-1" />
 		</antcall>
 		<!-- configsync -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="configsync" />
-			<param name="plugin.version" value="6.2.2" />
-			<param name="plugin.zip.version" value="6.2.2" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180614.214445-1" />
 		</antcall>
 		<!-- dataformat -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="dataformat" />
-			<param name="plugin.version" value="6.2.3" />
-			<param name="plugin.zip.version" value="6.2.3" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180615.130428-1" />
 		</antcall>
 		<!-- langfield -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="langfield" />
-			<param name="plugin.version" value="6.2.1" />
-			<param name="plugin.zip.version" value="6.2.1" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180615.131150-1" />
 		</antcall>
 		<!-- minhash -->
 		<antcall target="install.plugin">
-			<param name="repo.url" value="${maven.release.repo.url}" />
+			<param name="repo.url" value="${maven.snapshot.repo.url}" />
 			<param name="plugin.groupId" value="org/codelibs" />
 			<param name="plugin.name.prefix" value="elasticsearch-" />
 			<param name="plugin.name" value="minhash" />
-			<param name="plugin.version" value="6.2.1" />
-			<param name="plugin.zip.version" value="6.2.1" />
+			<param name="plugin.version" value="6.3.0-SNAPSHOT" />
+			<param name="plugin.zip.version" value="6.3.0-20180615.132619-1" />
 		</antcall>
 
 		<antcall target="remove.jars" />
diff --git a/pom.xml b/pom.xml
index 3c70e4993..53b9cf282 100644
--- a/pom.xml
+++ b/pom.xml
@@ -63,10 +63,10 @@
 		<crawler.version>2.2.0-SNAPSHOT</crawler.version>
 
 		<!-- Suggest -->
-		<suggest.version>6.2.1</suggest.version>
+		<suggest.version>6.3.0-SNAPSHOT</suggest.version>
 
 		<!-- Elasticsearch -->
-		<elasticsearch.version>6.2.4</elasticsearch.version>
+		<elasticsearch.version>6.3.0</elasticsearch.version>
 		<elasticsearch.min.version>6.0.0</elasticsearch.min.version>
 		<cluster.runner.version>${elasticsearch.version}.0</cluster.runner.version>
 
@@ -1265,6 +1265,11 @@
 			<artifactId>corelib</artifactId>
 			<version>0.4.0-SNAPSHOT</version>
 		</dependency>
+		<dependency>
+			<groupId>org.codelibs</groupId>
+			<artifactId>curl4j</artifactId>
+			<version>1.0.0</version>
+		</dependency>
 		<dependency>
 			<groupId>org.codelibs</groupId>
 			<artifactId>spnego</artifactId>
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 c2ab7df24..cb722dd57 100644
--- a/src/main/java/org/codelibs/fess/api/es/EsApiManager.java
+++ b/src/main/java/org/codelibs/fess/api/es/EsApiManager.java
@@ -33,8 +33,8 @@ import javax.servlet.http.HttpServletResponse;
 import org.apache.catalina.connector.ClientAbortException;
 import org.codelibs.core.io.CopyUtil;
 import org.codelibs.core.lang.StringUtil;
-import org.codelibs.elasticsearch.runner.net.Curl.Method;
-import org.codelibs.elasticsearch.runner.net.CurlRequest;
+import org.codelibs.curl.Curl.Method;
+import org.codelibs.curl.CurlRequest;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.api.BaseApiManager;
 import org.codelibs.fess.exception.FessSystemException;
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 76843712a..fca85c059 100644
--- a/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java
+++ b/src/main/java/org/codelibs/fess/api/json/JsonApiManager.java
@@ -15,7 +15,9 @@
  */
 package org.codelibs.fess.api.json;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.net.URLDecoder;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -56,7 +58,6 @@ import org.codelibs.fess.util.FacetResponse;
 import org.codelibs.fess.util.FacetResponse.Field;
 import org.dbflute.optional.OptionalThing;
 import org.elasticsearch.common.xcontent.ToXContent;
-import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.script.Script;
 import org.slf4j.Logger;
@@ -371,9 +372,9 @@ public class JsonApiManager extends BaseJsonApiManager {
     }
 
     protected String toGeoRequestString(final GeoInfo geoInfo) {
-        try {
-            final XContentBuilder builder = XContentFactory.jsonBuilder();
-            return geoInfo.toQueryBuilder().toXContent(builder, ToXContent.EMPTY_PARAMS).string();
+        try (OutputStream out =
+                geoInfo.toQueryBuilder().toXContent(XContentFactory.jsonBuilder(), ToXContent.EMPTY_PARAMS).getOutputStream()) {
+            return ((ByteArrayOutputStream) out).toString(Constants.UTF_8);
         } catch (final Exception e) {
             return "{\"error\":\"" + detailedMessage(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 0d9248bf1..847cbd3bd 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
@@ -41,7 +41,7 @@ import org.apache.commons.text.StringEscapeUtils;
 import org.codelibs.core.exception.IORuntimeException;
 import org.codelibs.core.io.CopyUtil;
 import org.codelibs.core.misc.Pair;
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
+import org.codelibs.curl.CurlResponse;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.app.web.base.FessAdminAction;
 import org.codelibs.fess.es.config.exbhv.FileConfigBhv;
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 fa91ca77f..c46071203 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
@@ -25,8 +25,8 @@ import java.util.Locale;
 import org.codelibs.core.io.CopyUtil;
 import org.codelibs.core.io.ReaderUtil;
 import org.codelibs.core.lang.StringUtil;
-import org.codelibs.elasticsearch.runner.net.CurlRequest;
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
+import org.codelibs.curl.CurlRequest;
+import org.codelibs.curl.CurlResponse;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.app.web.base.FessAdminAction;
 import org.codelibs.fess.helper.CurlHelper;
diff --git a/src/main/java/org/codelibs/fess/app/web/api/admin/backup/ApiAdminBackupAction.java b/src/main/java/org/codelibs/fess/app/web/api/admin/backup/ApiAdminBackupAction.java
index 15e42d0c2..acb1eb7c9 100644
--- a/src/main/java/org/codelibs/fess/app/web/api/admin/backup/ApiAdminBackupAction.java
+++ b/src/main/java/org/codelibs/fess/app/web/api/admin/backup/ApiAdminBackupAction.java
@@ -33,7 +33,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
 
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
+import org.codelibs.curl.CurlResponse;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.app.web.api.ApiResult;
 import org.codelibs.fess.app.web.api.ApiResult.ApiBackupFilesResponse;
diff --git a/src/main/java/org/codelibs/fess/dict/DictionaryManager.java b/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
index b84218fcb..e6a3fffe6 100644
--- a/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
+++ b/src/main/java/org/codelibs/fess/dict/DictionaryManager.java
@@ -27,7 +27,8 @@ import java.util.Map;
 import javax.annotation.PostConstruct;
 
 import org.codelibs.core.io.FileUtil;
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
+import org.codelibs.curl.CurlResponse;
+import org.codelibs.elasticsearch.runner.net.EcrCurl;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.util.ComponentUtil;
 import org.dbflute.optional.OptionalEntity;
@@ -50,7 +51,7 @@ public class DictionaryManager {
         try (CurlResponse response =
                 ComponentUtil.getCurlHelper().get("/_configsync/file").param("fields", "path,@timestamp")
                         .param("size", ComponentUtil.getFessConfig().getPageDictionaryMaxFetchSize()).execute()) {
-            final Map<String, Object> contentMap = response.getContentAsMap();
+            final Map<String, Object> contentMap = response.getContent(EcrCurl.jsonParser);
             @SuppressWarnings("unchecked")
             final List<Map<String, Object>> fileList = (List<Map<String, Object>>) contentMap.get("file");
             return fileList
@@ -96,7 +97,7 @@ public class DictionaryManager {
                 try (CurlResponse response =
                         ComponentUtil.getCurlHelper().post("/_configsync/file").param("path", dictFile.getPath())
                                 .body(FileUtil.readUTF8(file)).execute()) {
-                    final Map<String, Object> contentMap = response.getContentAsMap();
+                    final Map<String, Object> contentMap = response.getContent(EcrCurl.jsonParser);
                     if (!Constants.TRUE.equalsIgnoreCase(contentMap.get("acknowledged").toString())) {
                         throw new DictionaryException("Failed to update " + dictFile.getPath());
                     }
diff --git a/src/main/java/org/codelibs/fess/entity/PingResponse.java b/src/main/java/org/codelibs/fess/entity/PingResponse.java
index c2bb951e3..cd204a25d 100644
--- a/src/main/java/org/codelibs/fess/entity/PingResponse.java
+++ b/src/main/java/org/codelibs/fess/entity/PingResponse.java
@@ -15,13 +15,15 @@
  */
 package org.codelibs.fess.entity;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
 
 import org.codelibs.core.lang.StringUtil;
+import org.codelibs.fess.Constants;
 import org.elasticsearch.action.admin.cluster.health.ClusterHealthResponse;
 import org.elasticsearch.cluster.health.ClusterHealthStatus;
 import org.elasticsearch.common.xcontent.ToXContent;
-import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 
 public class PingResponse {
@@ -37,10 +39,8 @@ public class PingResponse {
         status = response.getStatus() == ClusterHealthStatus.RED ? 1 : 0;
         clusterName = response.getClusterName();
         clusterStatus = response.getStatus().toString();
-        try {
-            final XContentBuilder builder = XContentFactory.jsonBuilder();
-            response.toXContent(builder, ToXContent.EMPTY_PARAMS);
-            message = builder.string();
+        try (OutputStream out = response.toXContent(XContentFactory.jsonBuilder(), ToXContent.EMPTY_PARAMS).getOutputStream()) {
+            message = ((ByteArrayOutputStream) out).toString(Constants.UTF_8);
         } catch (final IOException e) {
             message = "{ \"error\" : \"" + e.getMessage() + "\"}";
         }
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 8e10b594f..bdb5c34cf 100644
--- a/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
+++ b/src/main/java/org/codelibs/fess/es/client/FessEsClient.java
@@ -43,9 +43,9 @@ import org.codelibs.core.exception.ResourceNotFoundRuntimeException;
 import org.codelibs.core.io.FileUtil;
 import org.codelibs.core.io.ResourceUtil;
 import org.codelibs.core.lang.StringUtil;
+import org.codelibs.curl.CurlResponse;
 import org.codelibs.elasticsearch.runner.ElasticsearchClusterRunner;
 import org.codelibs.elasticsearch.runner.ElasticsearchClusterRunner.Configs;
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.entity.FacetInfo;
 import org.codelibs.fess.entity.GeoInfo;
diff --git a/src/main/java/org/codelibs/fess/helper/CurlHelper.java b/src/main/java/org/codelibs/fess/helper/CurlHelper.java
index b6d4d69d8..34c7d0874 100644
--- a/src/main/java/org/codelibs/fess/helper/CurlHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/CurlHelper.java
@@ -15,8 +15,8 @@
  */
 package org.codelibs.fess.helper;
 
-import org.codelibs.elasticsearch.runner.net.Curl.Method;
-import org.codelibs.elasticsearch.runner.net.CurlRequest;
+import org.codelibs.curl.Curl.Method;
+import org.codelibs.curl.CurlRequest;
 import org.codelibs.fess.util.ResourceUtil;
 
 public class CurlHelper {
diff --git a/src/main/java/org/codelibs/fess/timer/SystemMonitorTarget.java b/src/main/java/org/codelibs/fess/timer/SystemMonitorTarget.java
index 0445ee3e0..55646276f 100644
--- a/src/main/java/org/codelibs/fess/timer/SystemMonitorTarget.java
+++ b/src/main/java/org/codelibs/fess/timer/SystemMonitorTarget.java
@@ -15,6 +15,8 @@
  */
 package org.codelibs.fess.timer;
 
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.Supplier;
@@ -22,6 +24,7 @@ import java.util.stream.Collectors;
 
 import org.apache.commons.text.StringEscapeUtils;
 import org.codelibs.core.timer.TimeoutTarget;
+import org.codelibs.fess.Constants;
 import org.codelibs.fess.es.client.FessEsClient;
 import org.codelibs.fess.util.ComponentUtil;
 import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
@@ -179,14 +182,16 @@ public class SystemMonitorTarget implements TimeoutTarget {
         try {
             final FessEsClient esClient = ComponentUtil.getFessEsClient();
             final NodesStatsResponse response =
-                    esClient.admin().cluster().prepareNodesStats().ingest(false).setBreaker(false).setDiscovery(false).setFs(true)
+                    esClient.admin().cluster().prepareNodesStats().setIngest(false).setBreaker(false).setDiscovery(false).setFs(true)
                             .setHttp(false).setIndices(true).setJvm(true).setOs(true).setProcess(true).setScript(false).setThreadPool(true)
                             .setTransport(true).execute().actionGet(10000L);
             final XContentBuilder builder = XContentFactory.jsonBuilder();
             builder.startObject();
-            response.toXContent(builder, ToXContent.EMPTY_PARAMS);
+            response.toXContent(XContentFactory.jsonBuilder(), ToXContent.EMPTY_PARAMS);
             builder.endObject();
-            stats = builder.string();
+            try (OutputStream out = builder.getOutputStream()) {
+                stats = ((ByteArrayOutputStream) out).toString(Constants.UTF_8);
+            }
         } catch (final Exception e) {
             logger.debug("Failed to access Elasticsearch stats.", e);
         }
diff --git a/src/main/java/org/codelibs/fess/util/UpgradeUtil.java b/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
index 90d88f6a3..f13ab104a 100644
--- a/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
+++ b/src/main/java/org/codelibs/fess/util/UpgradeUtil.java
@@ -20,7 +20,7 @@ import java.util.function.Consumer;
 
 import org.codelibs.core.exception.ResourceNotFoundRuntimeException;
 import org.codelibs.core.io.FileUtil;
-import org.codelibs.elasticsearch.runner.net.CurlResponse;
+import org.codelibs.curl.CurlResponse;
 import org.codelibs.fess.mylasta.direction.FessConfig;
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.admin.indices.alias.IndicesAliasesResponse;
diff --git a/src/test/java/org/codelibs/fess/helper/AccessTokenHelperTest.java b/src/test/java/org/codelibs/fess/helper/AccessTokenHelperTest.java
index efbbb2bb9..5948ac0e5 100644
--- a/src/test/java/org/codelibs/fess/helper/AccessTokenHelperTest.java
+++ b/src/test/java/org/codelibs/fess/helper/AccessTokenHelperTest.java
@@ -15,14 +15,13 @@
  */
 package org.codelibs.fess.helper;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-import org.codelibs.fess.unit.UnitFessTestCase;
 import org.codelibs.fess.exception.InvalidAccessTokenException;
-import org.codelibs.fess.util.ComponentUtil;
+import org.codelibs.fess.unit.UnitFessTestCase;
 import org.dbflute.utflute.mocklet.MockletHttpServletRequest;
 
 public class AccessTokenHelperTest extends UnitFessTestCase {
diff --git a/src/test/java/org/codelibs/fess/helper/QueryHelperTest.java b/src/test/java/org/codelibs/fess/helper/QueryHelperTest.java
index c330b915e..65cb46005 100644
--- a/src/test/java/org/codelibs/fess/helper/QueryHelperTest.java
+++ b/src/test/java/org/codelibs/fess/helper/QueryHelperTest.java
@@ -115,13 +115,13 @@ public class QueryHelperTest extends UnitFessTestCase {
                 "{\"function_score\":{\"query\":{\"wildcard\":{\"title\":{\"wildcard\":\"*\",\"boost\":1.0}}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
                 buildQuery("allintitle:").toString().replaceAll("\\s", ""));
         assertEquals(
-                "{\"function_score\":{\"query\":{\"match_phrase\":{\"title\":{\"query\":\"test\",\"slop\":0,\"boost\":1.0}}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
+                "{\"function_score\":{\"query\":{\"match_phrase\":{\"title\":{\"query\":\"test\",\"slop\":0,\"zero_terms_query\":\"NONE\",\"boost\":1.0}}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
                 buildQuery("allintitle:test").toString().replaceAll("\\s", ""));
         assertEquals(
-                "{\"function_score\":{\"query\":{\"match_phrase\":{\"title\":{\"query\":\"test\",\"slop\":0,\"boost\":1.0}}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
+                "{\"function_score\":{\"query\":{\"match_phrase\":{\"title\":{\"query\":\"test\",\"slop\":0,\"zero_terms_query\":\"NONE\",\"boost\":1.0}}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
                 buildQuery("allintitle: test").toString().replaceAll("\\s", ""));
         assertEquals(
-                "{\"function_score\":{\"query\":{\"bool\":{\"must\":[{\"match_phrase\":{\"title\":{\"query\":\"aaa\",\"slop\":0,\"boost\":1.0}}},{\"match_phrase\":{\"title\":{\"query\":\"bbb\",\"slop\":0,\"boost\":1.0}}}],\"adjust_pure_negative\":true,\"boost\":1.0}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
+                "{\"function_score\":{\"query\":{\"bool\":{\"must\":[{\"match_phrase\":{\"title\":{\"query\":\"aaa\",\"slop\":0,\"zero_terms_query\":\"NONE\",\"boost\":1.0}}},{\"match_phrase\":{\"title\":{\"query\":\"bbb\",\"slop\":0,\"zero_terms_query\":\"NONE\",\"boost\":1.0}}}],\"adjust_pure_negative\":true,\"boost\":1.0}},\"functions\":[{\"filter\":{\"match_all\":{\"boost\":1.0}},\"field_value_factor\":{\"field\":\"boost\",\"factor\":1.0,\"modifier\":\"none\"}}],\"score_mode\":\"multiply\",\"max_boost\":3.4028235E38,\"boost\":1.0}}",
                 buildQuery("allintitle: aaa bbb").toString().replaceAll("\\s", ""));
 
         assertEquals(
diff --git a/src/test/java/org/codelibs/fess/it/admin/SearchListTests.java b/src/test/java/org/codelibs/fess/it/admin/SearchListTests.java
index 6396309df..b3f263a89 100644
--- a/src/test/java/org/codelibs/fess/it/admin/SearchListTests.java
+++ b/src/test/java/org/codelibs/fess/it/admin/SearchListTests.java
@@ -15,13 +15,11 @@
  */
 package org.codelibs.fess.it.admin;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.hamcrest.Matchers.equalTo;
 
 import java.util.HashMap;
-import java.util.Map;
 import java.util.List;
-import java.util.Set;
+import java.util.Map;
 
 import org.codelibs.fess.it.CrudTestBase;
 import org.junit.jupiter.api.Tag;
diff --git a/src/test/java/org/codelibs/fess/util/DocMapTest.java b/src/test/java/org/codelibs/fess/util/DocMapTest.java
index 0bdb02e3c..9c521c8c6 100644
--- a/src/test/java/org/codelibs/fess/util/DocMapTest.java
+++ b/src/test/java/org/codelibs/fess/util/DocMapTest.java
@@ -15,12 +15,11 @@
  */
 package org.codelibs.fess.util;
 
-import java.util.Map;
-import java.util.Set;
-import java.util.List;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
-import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
 import org.codelibs.fess.unit.UnitFessTestCase;
 
diff --git a/src/test/java/org/codelibs/fess/util/KuromojiCSVUtilTest.java b/src/test/java/org/codelibs/fess/util/KuromojiCSVUtilTest.java
index 4003a97e0..116cc8321 100644
--- a/src/test/java/org/codelibs/fess/util/KuromojiCSVUtilTest.java
+++ b/src/test/java/org/codelibs/fess/util/KuromojiCSVUtilTest.java
@@ -15,11 +15,12 @@
  */
 package org.codelibs.fess.util;
 
-import java.util.List;
-import java.util.Arrays;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
 
+import java.util.Arrays;
+import java.util.List;
+
 import org.codelibs.fess.unit.UnitFessTestCase;
 
 public class KuromojiCSVUtilTest extends UnitFessTestCase {