fix wrong ordered smaller number is on the top

Author: Yang Guo

platform-core/src/main/java/com/flow/platform/core/queue/PriorityMessage.java

@@ -25,7 +25,7 @@
  */
 public class PriorityMessage extends Message implements PriorityQueueItem {
 
-    private long priority;
+    private Long priority;
 
     public static PriorityMessage create(byte[] content, long priority) {
         MessageProperties properties = new MessageProperties();
@@ -42,20 +42,12 @@ public PriorityMessage(byte[] body, MessageProperties messageProperties, long pr
     }
 
     @Override
-    public long getPriority() {
+    public Long getPriority() {
         return this.priority;
     }
 
     @Override
     public int compareTo(PriorityQueueItem o) {
-        if (o.getPriority() > priority) {
-            return -1;
-        }
-
-        if (o.getPriority() < priority) {
-            return 1;
-        }
-
-        return 0;
+        return o.getPriority().compareTo(getPriority());
     }
 }

platform-queue/src/main/java/com/flow/platform/queue/DefaultQueueMessage.java

@@ -23,15 +23,15 @@ public class DefaultQueueMessage implements PriorityQueueItem {
 
     private final byte[] body;
 
-    private long priority;
+    private Long priority;
 
-    public DefaultQueueMessage(byte[] body, Integer priority) {
+    public DefaultQueueMessage(byte[] body, Long priority) {
         this.body = body;
         this.priority = priority;
     }
 
     @Override
-    public long getPriority() {
+    public Long getPriority() {
         return priority;
     }
 
@@ -42,14 +42,6 @@ public byte[] getBody() {
 
     @Override
     public int compareTo(PriorityQueueItem o) {
-        if (o.getPriority() > priority) {
-            return -1;
-        }
-
-        if (o.getPriority() < priority) {
-            return 1;
-        }
-
-        return 0;
+        return o.getPriority().compareTo(getPriority());
     }
 }

platform-queue/src/main/java/com/flow/platform/queue/PriorityQueueItem.java

@@ -21,7 +21,7 @@
  */
 public interface PriorityQueueItem extends Comparable<PriorityQueueItem> {
 
-    long getPriority();
+    Long getPriority();
 
     byte[] getBody();
 }