事务工具类

public class TransactionsUtil {
    //创建线程
    private static ThreadLocal<Connection> threadLocal = new ThreadLocal<>();

    //获取连接
    public static Connection getConnection() throws PropertyVetoException, SQLException {
        Connection conn = threadLocal.get();//获取链接,如果没有自动创建副本
        if (conn == null) {
            //c3p0数据源
            conn = ComboPooledDataSourceUtil.getDataSourceByxml().getConnection();
            threadLocal.set(conn);
        }
        return conn;
    }

    //开启事务
    public static void begin() throws PropertyVetoException, SQLException {
        Connection conn = getConnection();//先获取链接
        if (conn != null) conn.setAutoCommit(false);//手动提交/开启事务
    }

    //提交事务
    public static void commit() throws PropertyVetoException, SQLException {
        Connection connection = getConnection();
        if (connection != null) connection.commit();
    }

    //事务回滚
    public static void rollback() throws PropertyVetoException, SQLException {
        Connection connection = getConnection();
        if (connection == null) connection.rollback();
    }

    //关闭线程和连接
    public static void close() throws PropertyVetoException, SQLException {
        Connection conn = getConnection();
        if (conn != null) conn.close();
        threadLocal.remove();
    }

}