fix #225 ID's sequence can not reset to zero

sharding-jdbc-doc/content/03-community/release-notes.md

@@ -20,6 +20,7 @@ next = "/03-community/directory-structure"
 1. [ISSUE #212](https://github.com/dangdangdotcom/sharding-jdbc/issues/212) 对去缺少数据源规则给出更有意义的提示
 1. [ISSUE #214](https://github.com/dangdangdotcom/sharding-jdbc/issues/214) where中 table_name.column_name in (?,?)无法解析表达式
 1. [ISSUE #180](https://github.com/dangdangdotcom/sharding-jdbc/issues/180) 批量执行Update返回值不准确
+1. [ISSUE #225](https://github.com/dangdangdotcom/sharding-jdbc/issues/225) 自动生成Id最后一位不归零
 
 ## 1.4.1
 

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/main/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/CommonSelfIdGenerator.java

@@ -112,15 +112,6 @@ public class CommonSelfIdGenerator implements IdGenerator {
         CommonSelfIdGenerator.workerId = workerId;
     }
     
-    /**
-     * 获取工作Id的二进制长度.
-     * 
-     * @return 工作Id的二进制长度
-     */
-    public static long getWorkerIdLength() {
-        return WORKER_ID_BITS;
-    }
-    
     /**
      * 生成Id.
      * 
@@ -131,7 +122,7 @@ public class CommonSelfIdGenerator implements IdGenerator {
         long time = clock.millis();
         Preconditions.checkState(lastTime <= time, "Clock is moving backwards, last time is %d milliseconds, current time is %d milliseconds", lastTime, time);
         if (lastTime == time) {
-            if (0L == (++sequence & SEQUENCE_MASK)) {
+            if (0L == (sequence = ++sequence & SEQUENCE_MASK)) {
                 time = waitUntilNextTime(time);
             }
         } else {

sharding-jdbc-id-generator-parent/sharding-jdbc-self-id-generator/src/test/java/com/dangdang/ddframe/rdb/sharding/id/generator/self/CommonSelfIdGeneratorTest.java

@@ -61,20 +61,16 @@ public class CommonSelfIdGeneratorTest {
     public void testMaxSequence() throws Exception {
         assertThat(maxId((1 << 12) - 1), is((1L << 12L) - 2));
         assertThat(maxId(1 << 12), is((1L << 12L) - 1));
-        assertThat(maxId((1 << 12) + 1), is((1L << 12L) - 1));
-        assertThat(maxId(1 << 13), is((1L << 12L) - 1));
-        assertThat(maxId((1 << 13) + 1), is((1L << 12L) - 1));
+        assertThat(maxId((1 << 12) + 1), is(1L << 22));
     }
     
     private long maxId(final int maxSequence) {
         CommonSelfIdGenerator idGenerator = new CommonSelfIdGenerator();
-        CommonSelfIdGenerator.setClock(new FixClock(maxSequence));
+        CommonSelfIdGenerator.setClock(new FixClock(1 << 13));
         long id = 0;
-        long preId = 0;
-        while (id < (1L << 12)) {
-            preId = id;
+        for (int i = 0; i < maxSequence; i++) {
             id = (Long) idGenerator.generateId();
         }
-        return preId;
+        return id;
     }
 }