fix #180 Batch update returns inaccurate

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/executor/PreparedStatementExecutor.java

@@ -204,8 +204,9 @@ private boolean executeInternal(final PreparedStatementExecutorWrapper preparedS
      * 执行批量接口.
      *
      * @return 每个
+     * @param batchSize 批量执行语句总数
      */
-    public int[] executeBatch() {
+    public int[] executeBatch(final int batchSize) {
         Context context = MetricsContext.start("ShardingPreparedStatement-executeUpdate");
         eventPostman.postExecutionEvents();
         final boolean isExceptionThrown = ExecutorExceptionHandler.isExceptionThrown();
@@ -229,15 +230,13 @@ public int[] merge(final List<int[]> results) {
                     if (null == results) {
                         return new int[]{0};
                     }
-                    int length = 0;
-                    for (int[] array : results) {
-                        length += array.length;
-                    }
-                    int[] result = new int[length];
-                    int pos = 0;
-                    for (int[] array : results) {
-                        System.arraycopy(array, 0, result, pos, array.length);
-                        pos += array.length;
+                    int[] result = new int[batchSize];
+                    int i = 0;
+                    for (PreparedStatementExecutorWrapper each : preparedStatementExecutorWrappers) {
+                        for (Integer[] indices : each.getBatchIndices()) {
+                            result[indices[0]] += results.get(i)[indices[1]];
+                        }
+                        i++;
                     }
                     return result;
                 }

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/executor/wrapper/PreparedStatementExecutorWrapper.java

@@ -26,6 +26,7 @@
 import lombok.Getter;
 
 import java.sql.PreparedStatement;
+import java.util.ArrayList;
 import java.util.List;
 
 /**
@@ -42,6 +43,11 @@ public class PreparedStatementExecutorWrapper extends AbstractExecutorWrapper {
 
     private final Optional<DQLExecutionEvent> dqlExecutionEvent;
 
+    @Getter
+    private final List<Integer[]> batchIndices = new ArrayList<>();
+
+    private int batchIndex;
+
     public PreparedStatementExecutorWrapper(final PreparedStatement preparedStatement, final List<Object> parameters,
                                             final SQLExecutionUnit sqlExecutionUnit) {
         super(sqlExecutionUnit);
@@ -77,4 +83,14 @@ public void addBatchParameters(final List<Object> parameters) {
         Preconditions.checkArgument(isDML() && dmlExecutionEvent.isPresent());
         dmlExecutionEvent.get().addBatchParameters(Lists.newArrayList(parameters));
     }
+
+    /**
+     * 映射批量执行索引.
+     * 将{@linkplain com.dangdang.ddframe.rdb.sharding.jdbc.ShardingPreparedStatement}批量执行索引映射为真实的{@linkplain PreparedStatement}批量执行索引.
+     * 
+     * @param shardingBatchIndex 分片批量执行索引
+     */
+    public void mapBatchIndex(final int shardingBatchIndex) {
+        batchIndices.add(new Integer[]{shardingBatchIndex, this.batchIndex++});
+    }
 }

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/jdbc/ShardingPreparedStatement.java

@@ -55,6 +55,8 @@ public final class ShardingPreparedStatement extends AbstractPreparedStatementAd
 
     private String[] columnNames;
 
+    private int batchIndex;
+
     ShardingPreparedStatement(final ShardingConnection shardingConnection, final String sql) {
         this(shardingConnection, sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY, ResultSet.HOLD_CURSORS_OVER_COMMIT);
     }
@@ -119,6 +121,7 @@ public boolean execute() throws SQLException {
     protected void clearRouteContext() throws SQLException {
         resetBatch();
         cachedPreparedStatementWrappers.clear();
+        batchIndex = 0;
     }
 
     @Override
@@ -131,7 +134,9 @@ public void addBatch() throws SQLException {
         try {
             for (PreparedStatementExecutorWrapper each : routeSQL()) {
                 each.getPreparedStatement().addBatch();
+                each.mapBatchIndex(batchIndex);
             }
+            batchIndex++;
             getGeneratedKeyContext().addRow();
         } finally {
             resetBatch();
@@ -146,7 +151,7 @@ private void resetBatch() throws SQLException {
     @Override
     public int[] executeBatch() throws SQLException {
         try {
-            return new PreparedStatementExecutor(getShardingConnection().getShardingContext().getExecutorEngine(), cachedPreparedStatementWrappers).executeBatch();
+            return new PreparedStatementExecutor(getShardingConnection().getShardingContext().getExecutorEngine(), cachedPreparedStatementWrappers).executeBatch(batchIndex);
         } finally {
             clearRouteContext();
         }

sharding-jdbc-core/src/test/java/com/dangdang/ddframe/rdb/sharding/jdbc/ShardingPreparedStatementTest.java

@@ -336,6 +336,32 @@ public void assertAddBatchWithAutoIncrementColumn() throws SQLException {
         }
     }
 
+    @Test
+    public void assertUpdateBatch() throws SQLException {
+        String sql = "UPDATE `t_order` SET `status` = ? WHERE  `status` = ?";
+        try (
+                Connection connection = shardingDataSource.getConnection();
+                PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
+            preparedStatement.setString(1, "batch");
+            preparedStatement.setString(2, "init");
+            preparedStatement.addBatch();
+            preparedStatement.setString(1, "batch");
+            preparedStatement.setString(2, "init");
+            preparedStatement.addBatch();
+            preparedStatement.setString(1, "init");
+            preparedStatement.setString(2, "batch");
+            preparedStatement.addBatch();
+
+            int[] result = preparedStatement.executeBatch();
+            assertThat(result.length, is(3));
+            assertThat(result[0], is(40));
+            assertThat(result[1], is(0));
+            assertThat(result[2], is(40));
+        } finally {
+            DMLExecutionEventBus.clearListener();
+        }
+    }
+
     @Test
     public void assertClearBatch() throws SQLException {
         String sql = "INSERT INTO `t_order`(`order_id`, `user_id`, `status`) VALUES (?,?,?)";

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

@@ -12,18 +12,14 @@ next = "/03-community/directory-structure"
 ### 功能提升
 
 1. [ISSUE #219](https://github.com/dangdangdotcom/sharding-jdbc/issues/219) 线程性能优化
+1. [ISSUE #215](https://github.com/dangdangdotcom/sharding-jdbc/issues/215) 流式排序的聚集结果集 StreamingOrderByReducerResultSet性能优化
+1. [ISSUE #161](https://github.com/dangdangdotcom/sharding-jdbc/issues/161) 结果集归并的时候可以采用堆排序来提升性能
 
 ### 缺陷修正
 
 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
-
-## 1.4.2
-
-### 功能提升
-
-1. [ISSUE #215](https://github.com/dangdangdotcom/sharding-jdbc/issues/215) 流式排序的聚集结果集 StreamingOrderByReducerResultSet性能优化
-1. [ISSUE #161](https://github.com/dangdangdotcom/sharding-jdbc/issues/161) 结果集归并的时候可以采用堆排序来提升性能
+1. [ISSUE #180](https://github.com/dangdangdotcom/sharding-jdbc/issues/180) 批量执行Update返回值不准确
 
 ## 1.4.1