ibatis中的的處理方法
首先在你的dao中需要繼承org.springframework.orm.ibatis.support.SqlMapClientDaoSupport
然后在代碼中調用getSqlMapClientTemplate方法， 獲取SqlMapClientTemplate對象，然后做處理
if (null == records || records.size() == 0) {
return;
}
// 執行回調
SqlMapClientTemplate sqlMapClientTemplate = iBatisDaoLS13.getSqlMapClientTemplate();
sqlMapClientTemplate.execute(new SqlMapClientCallback() {
// 實現回調接口
public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
// 開始批處理, for循環里面的sql必須一致，否則會創建新的PreparedStatement
executor.startBatch();
for (Info info : records) {
executor.insert(NAMESPACE + "insertAInfo", info);
}
// 執行批處理
executor.executeBatch();
return null;
}
});
}
mybatis中的的處理方法
@Test
public void testJDBCBatch() throws SQLException {
String sql = "insert into t_user(name, mobile, email) values(?,?,?)";
try (Connection conn = dataSource.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql);) {
List<User> users = this.getUsers();
for (User user : users) {
pstmt.setString(1, user.getName());
pstmt.setString(2, user.getMobile());
pstmt.setString(3, user.getEmail());
pstmt.addBatch();
}
pstmt.executeBatch();
conn.commit();
}
}
在每一次調用的時候是調用Statement.addBatch()方法，最終所有的參數都傳遞完了，沒有更多的參數時調用Statement.executeBatch()方法進行批量操作。在上一篇博文中我們查看了BatchExecutor的源碼，它的核心代碼doUpdate()方法，每次被調用的時候都是以handler.batch()結束，而handler.batch()對應的底層代碼是調用對應的Statement的addBatch()方法。那它是在什么時候執行executeBatch()呢？
@Override
public int doUpdate(MappedStatement ms, Object parameterObject) throws SQLException {
final Configuration configuration = ms.getConfiguration();
final StatementHandler handler = configuration.newStatementHandler(this, ms, parameterObject, RowBounds.DEFAULT, null, null);
final BoundSql boundSql = handler.getBoundSql();
final String sql = boundSql.getSql();
final Statement stmt;
if (sql.equals(currentSql) && ms.equals(currentStatement)) {
intlast = statementList.size() - 1;
stmt = statementList.get(last);
handler.parameterize(stmt);//fix Issues 322
BatchResult batchResult = batchResultList.get(last);
batchResult.addParameterObject(parameterObject);
} else {
Connection connection = getConnection(ms.getStatementLog());
stmt = handler.prepare(connection);
handler.parameterize(stmt); //fix Issues 322
currentSql = sql;
currentStatement = ms;
statementList.add(stmt);
batchResultList.add(new BatchResult(ms, sql, parameterObject));
}
// handler.parameterize(stmt);
handler.batch(stmt);
return BATCH_UPDATE_RETURN_VALUE;
}
它的executeBatch()是在doFlushStatements()方法調用中調用的，它會在當前Executor進行commit時調用，也會在當前Executor第一次執行doQuery()時調用，在這個時候都會調用Executor的flushStatements()方法，而BaseExecutor在執行flushStatements()時最終會調用其doFlushStatements()方法。當然，我們也可以手動的調用SqlSession的flushStatements()方法，其底層實現也會調用對應的BaseExecutor的flushStatements()方法。
@Override
public List<BatchResult> doFlushStatements(boolean isRollback) throws SQLException {
try {
List<BatchResult> results = new ArrayList<BatchResult>();
if (isRollback) {
return Collections.emptyList();
}
for (int i = 0, n = statementList.size(); i < n; i++) {
Statement stmt = statementList.get(i);
BatchResult batchResult = batchResultList.get(i);
try {
batchResult.setUpdateCounts(stmt.executeBatch());
MappedStatement ms = batchResult.getMappedStatement();
List<Object> parameterObjects = batchResult.getParameterObjects();
KeyGenerator keyGenerator = ms.getKeyGenerator();
if (Jdbc3KeyGenerator.class.equals(keyGenerator.getClass())) {
Jdbc3KeyGenerator jdbc3KeyGenerator = (Jdbc3KeyGenerator) keyGenerator;
jdbc3KeyGenerator.processBatch(ms, stmt, parameterObjects);
} else if (!NoKeyGenerator.class.equals(keyGenerator.getClass())) { //issue #141
for (Object parameter : parameterObjects) {
keyGenerator.processAfter(this, ms, stmt, parameter);
}
}
} catch (BatchUpdateException e) {
StringBuilder message = new StringBuilder();
message.append(batchResult.getMappedStatement().getId())
.append(" (batch index #")
.append(i + 1)
.append(")")
.append(" failed.");
if (i > 0) {
message.append(" ")
.append(i)
.append(" prior sub executor(s) completed successfully, but will be rolled back.");
}
throw new BatchExecutorException(message.toString(), e, results, batchResult);
}
results.add(batchResult);
}
return results;
} finally {
for (Statement stmt : statementList) {
closeStatement(stmt);
}
currentSql = null;
statementList.clear();
batchResultList.clear();
}
}
下面是一個使用Mybatis的BatchExecutor進行批量操作的示例。在示例中我們創建了一個使用BatchExecutor的SqlSession，也可以是SqlSessionTemplate，其實現了SqlSession接口，底層通過一個SqlSession代理進行相應的操作。然后在循環中一次調用對應Mapper的新增操作，相當於調用BatchExecutor的doUpdate()，最后調用SqlSession的commit()方法提交事務，在SqlSession的commit()中會調用Executor的commit()，從而導致了executeBatch()的發生。
@Test
public void testExecutor() {
SqlSession session = this.sessionFactory.openSession(ExecutorType.BATCH);
UserMapper mapper = session.getMapper(UserMapper.class);
User user = null;
for (inti = 0; i < 10; i++) {
user = new User();
user.setName("Name_" + i);
user.setEmail("email");
mapper.insert(user);
}
// 批量插入User
session.commit();// 提交事務時批量操作才會寫入數據庫
session.close();
}