DAO跨事物调用---转账

第一步创建实体类：Entity

package com.beiwo.epet.entity;

public class Account {
    private int id;

    private String name;

    private int money;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getMoney() {
        return money;
    }

    public void setMoney(int money) {
        this.money = money;
    }

}

第二步：基类接口和实现基类接口：Account AccountDaoImpl

package com.beiwo.epet.dao;

import com.beiwo.epet.entity.Account;

public interface  AccountDao {

    
    public void updateAccount(String fromName,String toName,int money)throws Exception;
    
    
    public void updateAccount(Account account)throws Exception;
    

    public Account findAccountByName(String name)throws Exception;
}




package com.beiwo.epet.dao.impl;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

import com.beiwo.epet.dao.AccountDao;
import com.beiwo.epet.entity.Account;
import com.beiwo.epet.util.C3P0Util;
import com.beiwo.epet.util.TransactionManager;

public class AccountDaoImpl implements AccountDao{

    @Override
    public void updateAccount(String fromName, String toName, int money) throws Exception{
        QueryRunner qr=new QueryRunner(C3P0Util.getDataSource());
        
        qr.update("UPDATE account SET money=money-? WHERE name=?",money,fromName);
        qr.update("UPDATE account SET money=money+? WHERE name=?",money,toName);
    }

    @Override
    public void updateAccount(Account account) throws Exception{
        QueryRunner qr=new QueryRunner();
        qr.update(TransactionManager.getConnection(),"UPDATE account SET money=? WHERE name=?", account.getMoney(),account.getName());
    }

    @Override
    public Account findAccountByName(String name) throws Exception{
        QueryRunner qr=new QueryRunner();
        return qr.query(TransactionManager.getConnection(),"SELECT * FROM account WHERE name=?",new BeanHandler<Account>(Account.class),name);

    }

    
    
}

第三步：业务逻辑接口和业务逻辑的实现：AccountService  AccountServiceImply

package com.beiwo.epet.service;

public interface AccountService {

    public void transfer(String formName,String toName,int money);
    
}






package com.beiwo.epet.service.impl;

import com.beiwo.epet.dao.AccountDao;
import com.beiwo.epet.dao.impl.AccountDaoImpl;
import com.beiwo.epet.entity.Account;
import com.beiwo.epet.service.AccountService;
import com.beiwo.epet.util.TransactionManager;

public class AccountServiceImpl implements AccountService{

    @Override
    public void transfer(String formName, String toName, int money) {
        AccountDao accountDao=new AccountDaoImpl(); 
        
        try {
            ///开始一个事务,start transaction;
            //获取转入和转出的账户对象
            TransactionManager.startTransaction();
            
            Account fromAccount=accountDao.findAccountByName(formName);
            Account toAccount=accountDao.findAccountByName(toName);
            
            //修改账户的各自金额
            fromAccount.setMoney(fromAccount.getMoney()-money);
            toAccount.setMoney(toAccount.getMoney()+money);
            
            //完成转账的操作
            accountDao.updateAccount(fromAccount);
            
            int i=2/0;
            
            accountDao.updateAccount(toAccount);
              
            TransactionManager.commitTransaction();
            
        } catch (Exception e) {
            try {
                TransactionManager.rollbackTransaction();;//事务的回滚
            } catch (Exception e2) {
                e2.printStackTrace();
            }
            
        }finally{
            try {
                TransactionManager.close();
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
        
        
    }

    
}

第四步：测试类 TesTransfer

package com.beiwo.epet.test;

import org.junit.Test;

import com.beiwo.epet.service.AccountService;
import com.beiwo.epet.service.impl.AccountServiceImpl;

public class TestTransfer {

    
    @Test
    public void test(){
        AccountService accountService=new AccountServiceImpl();
        
        accountService.transfer("aaa", "bbb", 100);
        
    }
}

数据库的建立：