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();
         }
     }
 }