test01

//JDBC中使用事务来模似转帐 
public class TransactionDemo1 {
	
	// 模拟转账成功时的业务场景
	public void testTransaction1() {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			conn.setAutoCommit(false);// 通知数据库开启事务(start transaction)
			String sql1 = "update account set money=money-100 where name='A'";
			ps = conn.prepareStatement(sql1);
			ps.executeUpdate();
			String sql2 = "update account set money=money+100 where name='B'";
			ps = conn.prepareStatement(sql2);
			ps.executeUpdate();
			conn.commit();// 上面的两条SQL执行Update语句成功之后就通知数据库提交事务(commit)
			System.out.println("成功");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JdbcUtils.release(conn, ps, rs);
		}
	}

	// 模拟转账过程中出现异常导致有一部分SQL执行失败后让数据库自动回滚事务
	public void testTransaction2() {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			conn.setAutoCommit(false);
			String sql1 = "update account set money=money-100 where name='A'";
			ps = conn.prepareStatement(sql1);
			ps.executeUpdate();
			// 用这句代码模拟执行完SQL1之后程序出现了异常而导致后面的SQL无法正常执行，
			// 事务也无法正常提交，此时数据库会自动执行回滚操作
			int x = 1 / 0;
			String sql2 = "update account set money=money+100 where name='B'";
			ps = conn.prepareStatement(sql2);
			ps.executeUpdate();
			conn.commit();
			System.out.println("成功");
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			JdbcUtils.release(conn, ps, rs);
		}
	}

	// 模拟转账过程中出现异常导致有一部分SQL执行失败时手动通知数据库回滚事务
	@Test
	public void testTransaction3() {
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		try {
			conn = JdbcUtils.getConnection();
			conn.setAutoCommit(false);
			String sql1 = "update account set money=money-100 where name='A'";
			ps = conn.prepareStatement(sql1);
			ps.executeUpdate();
			// 用这句代码模拟执行完SQL1之后程序出现了异常而导致后面的SQL无法正常执行，事务也无法正常提交
			int x = 1 / 0;
			String sql2 = "update account set money=money+100 where name='B'";
			ps = conn.prepareStatement(sql2);
			ps.executeUpdate();
			conn.commit();
			System.out.println("成功");
		} catch (Exception e) {
			try {
				// 捕获到异常之后手动通知数据库执行回滚事务的操作
				conn.rollback();
			} catch (SQLException e1) {
				e1.printStackTrace();
			}
			e.printStackTrace();
		} finally {
			JdbcUtils.release(conn, ps, rs);
		}
	}
}