#193: Handle messages as Sets instead of Lists

Signed-off-by: Jonas Arnhold <[email protected]>
amosproj · Jul 8, 2023 · 71d27b9 · 71d27b9
1 parent 67b17ac
commit 71d27b9
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Showing 3 changed files with 19 additions and 13 deletions.
diff --git a/backend/src/main/java/de/amos/apachepulsarui/controller/MessageController.java b/backend/src/main/java/de/amos/apachepulsarui/controller/MessageController.java
@@ -18,6 +18,7 @@
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
+import java.util.Set;
 
 @RestController
 @RequestMapping("/messages")
@@ -30,8 +31,10 @@ public class MessageController {
     public ResponseEntity<MessagesDto> getMessages(@RequestParam String topic,
                                                    @RequestParam(required = false, defaultValue = "10") Integer numMessages,
                                                    @RequestParam(required = false, defaultValue = "") List<String> producers,
-                                                   @RequestParam(required = false, defaultValue = "") List<String> subscriptions) {
-        List<MessageDto> messageDtos = messageService.getLatestMessagesFiltered(topic, numMessages, producers, subscriptions);
+                                                   @RequestParam(required = false, defaultValue = "") List<String> subscriptions)
+    {
+        Set<MessageDto> messageDtos = messageService.getLatestMessagesFiltered(topic, numMessages, producers, subscriptions);
         return new ResponseEntity<>(new MessagesDto(messageDtos), HttpStatus.OK);
     }
+
 }
diff --git a/backend/src/main/java/de/amos/apachepulsarui/dto/MessagesDto.java b/backend/src/main/java/de/amos/apachepulsarui/dto/MessagesDto.java
@@ -8,13 +8,13 @@
 import lombok.AllArgsConstructor;
 import lombok.Data;
 
-import java.util.List;
+import java.util.Set;
 
 
 @Data
 @AllArgsConstructor
 public class MessagesDto {
 
-    private List<MessageDto> messages;
+    private Set<MessageDto> messages;
 
 }
diff --git a/backend/src/main/java/de/amos/apachepulsarui/service/MessageService.java b/backend/src/main/java/de/amos/apachepulsarui/service/MessageService.java
@@ -20,15 +20,17 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 @Service
 @Slf4j
 @RequiredArgsConstructor
 public class MessageService {
     private final PulsarAdmin pulsarAdmin;
 
-    public List<MessageDto> getLatestMessagesFiltered(String topic, Integer numMessages, List<String> producers, List<String> subscriptions) {
-        List<MessageDto> messageDtos = getLatestMessagesOfTopic(topic, numMessages);
+    public Set<MessageDto> getLatestMessagesFiltered(String topic, Integer numMessages, List<String> producers, List<String> subscriptions) {
+        Set<MessageDto> messageDtos = getLatestMessagesOfTopic(topic, numMessages);
         if (!producers.isEmpty()) {
             messageDtos = filterByProducers(messageDtos, producers);
         }
@@ -39,12 +41,14 @@ public List<MessageDto> getLatestMessagesFiltered(String topic, Integer numMessa
         return messageDtos;
     }
 
-    private List<MessageDto> filterBySubscription(List<MessageDto> messageDtos, Integer numMessages, String topic, List<String> subscriptions) {
+    private Set<MessageDto> filterBySubscription(Set<MessageDto> messageDtos, Integer numMessages, String topic, List<String> subscriptions) {
         List<String> messageIds = subscriptions.stream()
                 .flatMap(s -> peekMessageIds(topic, s, numMessages).stream())
                 .toList();
 
-        return messageDtos.stream().filter(m -> messageIds.contains(m.getMessageId())).toList();
+        return messageDtos.stream()
+                .filter(m -> messageIds.contains(m.getMessageId()))
+                .collect(Collectors.toSet());
     }
 
     private List<String> peekMessageIds(String topic, String subscription, Integer numMessages) {
@@ -60,14 +64,13 @@ private List<String> peekMessageIds(String topic, String subscription, Integer n
     }
 
 
-    private List<MessageDto> filterByProducers(List<MessageDto> messageDtos, List<String> producers) {
+    private Set<MessageDto> filterByProducers(Set<MessageDto> messageDtos, List<String> producers) {
         return messageDtos.stream()
                 .filter(m -> producers.contains(m.getProducer()))
-                .toList();
-
+                .collect(Collectors.toSet());
     }
 
-    private List<MessageDto> getLatestMessagesOfTopic(String topic, Integer numMessages) {
+    private Set<MessageDto> getLatestMessagesOfTopic(String topic, Integer numMessages) {
         var schema = getSchemaIfExists(topic);
         try {
             var messages = new ArrayList<Message<byte[]>>();
@@ -83,7 +86,7 @@ private List<MessageDto> getLatestMessagesOfTopic(String topic, Integer numMessa
             }
             return messages.stream()
                     .map(message -> MessageDto.fromExistingMessage(message, schema))
-                    .toList();
+                    .collect(Collectors.toSet());
         } catch (PulsarAdminException e) {
             throw new PulsarApiException(
                     "Could not examine the amount of '%d' messages for topic '%s'".formatted(numMessages, topic),