[ISSUE #9479] Relax topic length constraint when creating retry and dlq topics (#9480)

Author: Allenhuangrui

common/src/main/java/org/apache/rocketmq/common/topic/TopicValidator.java

@@ -18,6 +18,7 @@
 
 import java.util.HashSet;
 import java.util.Set;
+import org.apache.rocketmq.common.MixAll;
 import org.apache.rocketmq.common.UtilAll;
 
 public class TopicValidator {
@@ -38,6 +39,7 @@ public class TopicValidator {
 
     public static final boolean[] VALID_CHAR_BIT_MAP = new boolean[128];
     private static final int TOPIC_MAX_LENGTH = 127;
+    private static final int RETRY_OR_DLQ_TOPIC_MAX_LENGTH = 255;
 
     private static final Set<String> SYSTEM_TOPIC_SET = new HashSet<>();
 
@@ -111,8 +113,14 @@ public static ValidateTopicResult validateTopic(String topic) {
             return new ValidateTopicResult(false, "The specified topic contains illegal characters, allowing only ^[%|a-zA-Z0-9_-]+$");
         }
 
-        if (topic.length() > TOPIC_MAX_LENGTH) {
-            return new ValidateTopicResult(false, "The specified topic is longer than topic max length.");
+        if (topic.startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX) || topic.startsWith(MixAll.DLQ_GROUP_TOPIC_PREFIX)) {
+            if (topic.length() > RETRY_OR_DLQ_TOPIC_MAX_LENGTH) {
+                return new ValidateTopicResult(false, "The specified topic is longer than topic max length.");
+            }
+        } else {
+            if (topic.length() > TOPIC_MAX_LENGTH) {
+                return new ValidateTopicResult(false, "The specified topic is longer than topic max length.");
+            }
         }
 
         return new ValidateTopicResult(true, "");

common/src/test/java/org/apache/rocketmq/common/topic/TopicValidatorTest.java

@@ -35,13 +35,37 @@ public void testTopicValidator_NotPass() {
         res = TopicValidator.validateTopic(generateString(128));
         assertThat(res.isValid()).isFalse();
         assertThat(res.getRemark()).contains("The specified topic is longer than topic max length.");
+
+        res = TopicValidator.validateTopic(generateString2(128));
+        assertThat(res.isValid()).isFalse();
+        assertThat(res.getRemark()).contains("The specified topic is longer than topic max length.");
+
+        res = TopicValidator.validateTopic(generateRetryTopic(256));
+        assertThat(res.isValid()).isFalse();
+        assertThat(res.getRemark()).contains("The specified topic is longer than topic max length.");
+
+        res = TopicValidator.validateTopic(generateDlqTopic(256));
+        assertThat(res.isValid()).isFalse();
+        assertThat(res.getRemark()).contains("The specified topic is longer than topic max length.");
     }
 
     @Test
     public void testTopicValidator_Pass() {
         TopicValidator.ValidateTopicResult res = TopicValidator.validateTopic("TestTopic");
         assertThat(res.isValid()).isTrue();
         assertThat(res.getRemark()).isEmpty();
+
+        res = TopicValidator.validateTopic(generateString2(127));
+        assertThat(res.isValid()).isTrue();
+        assertThat(res.getRemark()).isEmpty();
+
+        res = TopicValidator.validateTopic(generateRetryTopic(255));
+        assertThat(res.isValid()).isTrue();
+        assertThat(res.getRemark()).isEmpty();
+
+        res = TopicValidator.validateTopic(generateDlqTopic(255));
+        assertThat(res.isValid()).isTrue();
+        assertThat(res.getRemark()).isEmpty();
     }
 
     @Test
@@ -115,4 +139,30 @@ private static String generateString(int length) {
         }
         return stringBuffer.toString();
     }
+
+    private static String generateString2(int length) {
+        StringBuilder stringBuilder = new StringBuilder();
+        for (int i = 0; i < length; i++) {
+            stringBuilder.append("a");
+        }
+        return stringBuilder.toString();
+    }
+
+    private static String generateRetryTopic(int length) {
+        StringBuilder stringBuilder = new StringBuilder();
+        stringBuilder.append("%RETRY%");
+        for (int i = 0; i < length - 7; i++) {
+            stringBuilder.append("a");
+        }
+        return stringBuilder.toString();
+    }
+
+    private static String generateDlqTopic(int length) {
+        StringBuilder stringBuilder = new StringBuilder();
+        stringBuilder.append("%DLQ%");
+        for (int i = 0; i < length - 5; i++) {
+            stringBuilder.append("a");
+        }
+        return stringBuilder.toString();
+    }
 }