JAVA如何设置手动提交事务,回滚事务,提交事务

/**
  * 设置数据库是否自动提交事务
  * @param flag
  * @throws SQLException
  */
 public void setAutoCommit(boolean flag) throws SQLException {
  con.setAutoCommit(flag);
 }
 
 /**
  * 提交
  * @throws SQLException
  */
 public void commit() throws SQLException {
  con.commit();
 }
 
 /**
  * 回滚
  * @throws SQLException
  */
 public void rollback() throws SQLException {
  con.rollback();
 }

List<OrdLogSyn> ordLogSynList = ordLogSynMapper.batchQuery("AP", "20190926", "0", "1000");
  for (int i = 0; i < 2; i++) {
   DefaultTransactionDefinition def = new DefaultTransactionDefinition();
   def.setPropagationBehavior(DefaultTransactionDefinition.PROPAGATION_REQUIRES_NEW);
   TransactionStatus status = platformTransactionManager.getTransaction(def);
   List<OrdLogSyn> subList = null;
   if (i==0){
    subList = ordLogSynList.subList(0, 500);
   }else if (i==1){
    subList = ordLogSynList.subList(501, 1000);
   }
   for (OrdLogSyn ordLogSyn : subList) {
    int q = ordLogSynMapper.updateChkFlag(ordLogSyn.getConfirmSeqId(), ordLogSyn.getAcctDate(), "I");
    System.out.println("q = " + q);
   }
   platformTransactionManager.commit(status);
 
  }