Java操作数据库——在JDBC里使用事务

Java操作数据库——在JDBC里使用事务

摘要：本文主要学习了如何在JDBC里使用事务。

使用Connection的事务控制方法

当JDBC程序向数据库获得一个Connection对象时，默认情况下这个Connection对象会自动向数据库提交发送的SQL语句。若想关闭这种默认提交方式，让多条SQL在一个事务中执行，可使用JDBC提供的事务控制方法。

常用方法

查询自动提交的状态：boolean getAutoCommit() throws SQLException;

设置自动提交的状态：void setAutoCommit(boolean autoCommit) throws SQLException;

设置还原点：Savepoint setSavepoint() throws SQLException;

设置指定名称的还原点：Savepoint setSavepoint(String name) throws SQLException;

删除指定名称的还原点：void releaseSavepoint(Savepoint savepoint) throws SQLException;

提交：void commit() throws SQLException;

回滚：void rollback() throws SQLException;

回滚到指定名称的还原点：void rollback(Savepoint savepoint) throws SQLException;

查询隔离级别：int getTransactionIsolation() throws SQLException;

设置隔离级别：void setTransactionIsolation(int level) throws SQLException;

使用实例

public static void main(String[] args) {
    Properties pros = new Properties();
    try {
        pros.load(TestConnection.class.getClassLoader().getResourceAsStream("jdbc.properties"));
    } catch (IOException e) {
        e.printStackTrace();
    }
    try {
        Class.forName(pros.getProperty("driverClass"));
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
    Connection conn = null;
    PreparedStatement pstmt = null;
    try {
        String url = pros.getProperty("url");
        String user = pros.getProperty("user");
        String password = pros.getProperty("password");
        conn = DriverManager.getConnection(url, user, password);
        boolean status = conn.getAutoCommit();
        System.out.println("AutoCommit = " + status);
        conn.setAutoCommit(false);
        pstmt = conn.prepareStatement("delete from student where id = 906");
        pstmt.executeUpdate();
        int e = 1 / 0;// 模拟出现异常
        pstmt = conn.prepareStatement("delete from student where id = 907");
        pstmt.executeUpdate();
        conn.commit();// 手动提交，不能省略
    } catch (Exception e) {
        e.printStackTrace();
        try {
            conn.rollback();// 手动回滚，可以省略，系统会自动回滚
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    } finally {
        try {
            pstmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}