Requirements for transfer transaction cases: 1 Employee 1 transfers money to employee 2. Therefore, two update sals should be executed. Purpose: either both updates are successful or both implementati

package com.htf.demo;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.htf.util.DBUtils;

/** 
 *  Transfer accounts , Open transaction , Or at the same time , Or fail at the same time 
* @author : htf 
*  Transaction case requirements ：
* 1. staff 1 To employees 2 Transfer accounts    So we need to execute two  update sal
*  Purpose ： Or they are all updated successfully , Or they all fail 
*/

public class Test {

	private static final String UPDATE_EMP="update t_emp set sal=sal+? where empno=?";
	/**
	 *  Transfer accounts   Transfer according to the number 
	 * @param from  Number always 
	 * @param to   No. 2 transfer 
	 * @param money   How much is it 
	 * @return  ture It means the transfer is successful ,false Transfer failure 
	 */
	public boolean transfer(Integer from,Integer to,Double money) {
		boolean result =false;
		Connection conn=null;
		PreparedStatement stmt=null;
		try {
			conn=DBUtils.getConnection();
			conn.setAutoCommit(false);// Turn off auto commit transactions 
			stmt=conn.prepareStatement(UPDATE_EMP);
			stmt.setDouble(1, -money);
			stmt.setInt(2, from);
			
			int rows1=stmt.executeUpdate();
			
			stmt.setDouble(1, money);
			stmt.setInt(2, to);
			
			int rows2=stmt.executeUpdate();
			
			if(rows1==1 && rows2==1) {
				result=true;// Transfer succeeded 
				conn.commit();// Commit transaction 
			}
			
		} catch (Exception e) {
			e.printStackTrace();// Transfer failure 
			try {
				conn.rollback();// Roll back the transaction 
			} catch (SQLException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
		}
		
		return result;
	}
	
	public static void main(String[] args) {
		Test t1=new Test();
		t1.transfer(4446, 4447, 1.0);
	}
	
}