代码优化，由IDEA自动进行的Code Cleanup

weixin-java-common/src/main/java/me/chanjar/weixin/common/api/WxErrorExceptionHandler.java

@@ -7,6 +7,6 @@ import me.chanjar.weixin.common.exception.WxErrorException;
  */
 public interface WxErrorExceptionHandler {
 
-  public void handle(WxErrorException e);
+  void handle(WxErrorException e);
 
 }

weixin-java-common/src/main/java/me/chanjar/weixin/common/api/WxMessageDuplicateChecker.java

@@ -22,6 +22,6 @@ public interface WxMessageDuplicateChecker {
    * @param messageId messageId需要根据上面讲的方式构造
    * @return 如果是重复消息，返回true，否则返回false
    */
-  public boolean isDuplicate(String messageId);
+  boolean isDuplicate(String messageId);
 
 }

weixin-java-common/src/main/java/me/chanjar/weixin/common/api/WxMessageInMemoryDuplicateChecker.java

@@ -87,11 +87,7 @@ public class WxMessageInMemoryDuplicateChecker implements WxMessageDuplicateChec
     }
     checkBackgroundProcessStarted();
     Long timestamp = msgId2Timestamp.putIfAbsent(messageId, System.currentTimeMillis());
-    if (timestamp == null) {
-      // 第一次接收到这个消息
-      return false;
-    }
-    return true;
+    return timestamp != null;
   }