Spring-tx-PlatformTransactionManager(DataSourceTransactionManager)

事务管理接口，负责事务的创建，提交，回滚，三个操作

//创建事务，返回该事务的状态
  TransactionStatus getTransaction(@Nullable TransactionDefinition definition) throws TransactionException;

  //提交事务，具体提交哪个事务，由参数status决定
  void commit(TransactionStatus status) throws TransactionException;
  //事务回滚，滚到哪里，由参数status决定，也可以理解由
  //TransactionStatus中的savepoint属性决定
  void rollback(TransactionStatus status) throws TransactionException;

PlatformTransactionManager接口最重要的实现类是DataSourceTransactionManager，下面的事例使用该实现类演示事务的提交

示例1：手动提交事务，这个例子依赖于spring容器

@Autowired
DataSourceTransactionManager tx

public void aa(){
  DefaultTransactionDefinition def=new DefaultTransactionDefinition();
  //这个地方可以根据自己需要选择传播行为和隔离级别
  def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW);
  TransactionStatus status=tx.getTransaction(def);
  try{
  自己的各种业务操作
  tx.commit();//然后这里提交
  }catch(Exception e){
  tx.rollback(status);//报错这里回滚
  }
}

示例2：要想理解spring，就不应该依赖spring容器，同样是个手动提交事务，下面这个例子不再依赖spring容器

public static void main(String[] args) throws SQLException {
  HikariDataSource ds = new HikariDataSource();
  ds.setJdbcUrl("jdbc:mysql://localhost:3306/swttest?serverTimezone=UTC&&useSSL=false");
  ds.setUsername("root");
  ds.setPassword("123456");
  PlatformTransactionManager manager = new DataSourceTransactionManager(ds);
  DefaultTransactionAttribute td = new DefaultTransactionAttribute();
  TransactionStatus status = manager.getTransaction(td);

  Map<Object, Object> resourceMap = TransactionSynchronizationManager.getResourceMap();
  ConnectionHolder connectionHolder = (ConnectionHolder) resourceMap.get(ds);
  Connection conn = connectionHolder.getConnection();
  conn.prepareStatement("insert into t1(value) values ('二抱三抱是真抗冻')").execute();
  manager.commit(status);
  // manager.rollback(status);
}