optimize code

core/src/main/java/io/seata/core/util/IdWorker.java

@@ -109,8 +109,8 @@ public long nextId() {
             } else {
                 sequence = 0L;
             }
+            lastTimestamp = timestamp;
         }
-        lastTimestamp = timestamp;
         return ((timestamp - twepoch) << timestampLeftShift) | (workerId << workerIdShift) | sequence;
     }
 

server/src/main/java/io/seata/server/UUIDGenerator.java

@@ -34,9 +34,11 @@ public class UUIDGenerator {
     public static long generateUUID() {
         return idWorker.nextId();
     }
+
     /**
-     * IdWorker Instantiate by service node
+     * Init.
      *
+     * @param serverNode the server node id
      */
     public static void init(Long serverNode) {
         IdWorker.init(serverNode);

server/src/test/java/io/seata/server/UUIDGeneratorOverflowTest.java

@@ -31,7 +31,7 @@ public class UUIDGeneratorOverflowTest {
      */
     @Test
     public void testGenerateUUID() {
-        IdWorker.init(SERVER_NODE_ID);
+        UUIDGenerator.init(SERVER_NODE_ID);
         for (int i = 0; i < UUID_GENERATE_COUNT; i++) {
             System.out.println("[UUID " + i + "] is: " + UUIDGenerator.generateUUID());
         }