fix( #506 ): 修复只连上一个 TM 节点时，还负载均衡的问题

txlcn-protocol/src/main/java/com/codingapi/txlcn/protocol/message/separate/AbsMessage.java

@@ -31,10 +31,6 @@ public abstract class AbsMessage implements Message {
      */
     protected Boolean isReadyCallBack = false;
 
-    protected Connection tcConnection;
-
-    protected String firstConnectionKey;
-
     protected String messageId;
 
     protected String firstMessageId;

txlcn-protocol/src/main/java/com/codingapi/txlcn/protocol/message/separate/TransactionMessage.java

@@ -15,7 +15,7 @@ import org.springframework.context.ApplicationContext;
  */
 @EqualsAndHashCode(callSuper = true)
 @Data
-public  class TransactionMessage extends AbsMessage {
+public class TransactionMessage extends AbsMessage {
 
     protected String groupId;
 

txlcn-protocol/src/main/java/com/codingapi/txlcn/protocol/service/ConnectionService.java

@@ -17,7 +17,7 @@ import java.util.Map;
 public class ConnectionService {
 
     // server name -> connection
-    private final Map<String, Connection> connections = new HashMap<String, Connection>();
+    private final Map<String, Connection> connections = new HashMap<>();
 
     public void addConnection(final Connection connection) {
         final String uniqueKey = connection.getUniqueKey();

txlcn-tm/src/main/java/com/codingapi/txlcn/tm/loadbalancer/EventStatus.java

@@ -36,4 +36,11 @@ public interface EventStatus {
      * @param firstConnectionKeyTmp 暂时保存 ConnectionUniKey
      */
     void onReadyCallBack(AbsMessage absMessage, Protocoler protocoler, String firstConnectionKeyTmp);
+
+    /**
+     * TM 节点只连接了一个 TC 时
+     *
+     * @param event EventService
+     */
+    void onOneConnection(EventService event) throws Exception;
 }

txlcn-tm/src/main/java/com/codingapi/txlcn/tm/loadbalancer/EventStatusHandler.java

@@ -58,6 +58,12 @@ public class EventStatusHandler implements EventStatus {
         }
     }
 
+    @Override
+    public void onOneConnection(EventService event) throws Exception {
+        log.debug("EventStatusHandler.onOneConnection");
+        event.execute();
+    }
+
     /**
      * 判断 AbsMessage 是来自哪个事件的，并 new 一个该事件
      *

txlcn-tm/src/main/java/com/codingapi/txlcn/tm/loadbalancer/LoadBalancerInterceptor.java

@@ -43,9 +43,14 @@ public class LoadBalancerInterceptor implements EventInterceptor {
             throws Exception {
         String firstConnectionKeyTmp = connection.getUniqueKey();
         String firstMessageIdTmp = absMessage.getMessageId();
-        eventStatus.onFirstNode(absMessage, firstMessageIdTmp, connection);
-        eventStatus.onBusinessExecuted(absMessage, event);
-        eventStatus.onReadyCallBack(absMessage, protocoler, firstConnectionKeyTmp);
+        if (protocoler.getConnections().size() == 1) {
+            eventStatus.onOneConnection(event);
+        } else {
+            eventStatus.onFirstNode(absMessage, firstMessageIdTmp, connection);
+            eventStatus.onBusinessExecuted(absMessage, event);
+            eventStatus.onReadyCallBack(absMessage, protocoler, firstConnectionKeyTmp);
+        }
+
     }
 
     /**