added partition parameter

kafka-ui-api/src/main/java/com/provectus/kafka/ui/cluster/service/ClusterService.java

@@ -197,14 +197,15 @@ public class ClusterService {
                 .orElse(Flux.empty());
     }
 
-    public Mono<Void> deleteTopicMessages(String clusterName, String topicName) {
+    public Mono<Void> deleteTopicMessages(String clusterName, String topicName, Optional<Integer> partition) {
         var cluster = clustersStorage.getClusterByName(clusterName)
                 .orElseThrow(() -> new NotFoundException("No such cluster"));
         var partitions = getTopicDetails(clusterName, topicName)
                 .orElseThrow(() -> new NotFoundException("No such topic"))
                 .getPartitions().stream()
                 .map(Partition::getPartition)
-                .map(partition -> new TopicPartition(topicName, partition))
+                .filter(p -> partition.isEmpty() || partition.get().equals(p))
+                .map(p-> new TopicPartition(topicName, p))
                 .collect(Collectors.toList());
         return consumingService.loadOffsets(cluster, partitions)
                 .flatMap(offsets -> kafkaService.deleteTopicMessages(cluster, topicName, offsets));

kafka-ui-api/src/main/java/com/provectus/kafka/ui/rest/MetricsRestController.java

@@ -18,6 +18,7 @@ import reactor.core.publisher.Mono;
 import javax.validation.Valid;
 import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.function.Function;
 
 @RestController
@@ -85,8 +86,8 @@ public class MetricsRestController implements ApiClustersApi {
     }
 
     @Override
-    public Mono<ResponseEntity<Void>> deleteTopicMessages(String clusterName, String topicName, ServerWebExchange exchange) {
-        return clusterService.deleteTopicMessages(clusterName, topicName).map(ResponseEntity::ok);
+    public Mono<ResponseEntity<Void>> deleteTopicMessages(String clusterName, String topicName, @Valid Integer partition, ServerWebExchange exchange) {
+        return clusterService.deleteTopicMessages(clusterName, topicName, Optional.ofNullable(partition)).map(ResponseEntity::ok);
     }
 
     @Override

kafka-ui-contract/src/main/resources/swagger/kafka-ui-api.yaml

@@ -325,6 +325,11 @@ paths:
           required: true
           schema:
             type: string
+        - name: partition
+          in: query
+          required: false
+          schema:
+            type: integer
       responses:
         200:
           description: OK