DAO跨事物调用---转账

第一步创建实体类：Entity

 1 package com.beiwo.epet.entity;
 2 
 3 public class Account {
 4     private int id;
 5 
 6     private String name;
 7 
 8     private int money;
 9 
10     public int getId() {
11         return id;
12     }
13 
14     public void setId(int id) {
15         this.id = id;
16     }
17 
18     public String getName() {
19         return name;
20     }
21 
22     public void setName(String name) {
23         this.name = name;
24     }
25 
26     public int getMoney() {
27         return money;
28     }
29 
30     public void setMoney(int money) {
31         this.money = money;
32     }
33 
34 }

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

 1 package com.beiwo.epet.dao;
 2 
 3 import com.beiwo.epet.entity.Account;
 4 
 5 public interface  AccountDao {
 6 
 7     
 8     public void updateAccount(String fromName,String toName,int money)throws Exception;
 9     
10     
11     public void updateAccount(Account account)throws Exception;
12     
13 
14     public Account findAccountByName(String name)throws Exception;
15 }
16 
17 
18 
19 
20 package com.beiwo.epet.dao.impl;
21 
22 import org.apache.commons.dbutils.QueryRunner;
23 import org.apache.commons.dbutils.handlers.BeanHandler;
24 
25 import com.beiwo.epet.dao.AccountDao;
26 import com.beiwo.epet.entity.Account;
27 import com.beiwo.epet.util.C3P0Util;
28 import com.beiwo.epet.util.TransactionManager;
29 
30 public class AccountDaoImpl implements AccountDao{
31 
32     @Override
33     public void updateAccount(String fromName, String toName, int money) throws Exception{
34         QueryRunner qr=new QueryRunner(C3P0Util.getDataSource());
35         
36         qr.update("UPDATE account SET money=money-? WHERE name=?",money,fromName);
37         qr.update("UPDATE account SET money=money+? WHERE name=?",money,toName);
38     }
39 
40     @Override
41     public void updateAccount(Account account) throws Exception{
42         QueryRunner qr=new QueryRunner();
43         qr.update(TransactionManager.getConnection(),"UPDATE account SET money=? WHERE name=?", account.getMoney(),account.getName());
44     }
45 
46     @Override
47     public Account findAccountByName(String name) throws Exception{
48         QueryRunner qr=new QueryRunner();
49         return qr.query(TransactionManager.getConnection(),"SELECT * FROM account WHERE name=?",new BeanHandler<Account>(Account.class),name);
50 
51     }
52 
53     
54     
55 }

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

 1 package com.beiwo.epet.service;
 2 
 3 public interface AccountService {
 4 
 5     public void transfer(String formName,String toName,int money);
 6     
 7 }
 8 
 9 
10 
11 
12 
13 
14 package com.beiwo.epet.service.impl;
15 
16 import com.beiwo.epet.dao.AccountDao;
17 import com.beiwo.epet.dao.impl.AccountDaoImpl;
18 import com.beiwo.epet.entity.Account;
19 import com.beiwo.epet.service.AccountService;
20 import com.beiwo.epet.util.TransactionManager;
21 
22 public class AccountServiceImpl implements AccountService{
23 
24     @Override
25     public void transfer(String formName, String toName, int money) {
26         AccountDao accountDao=new AccountDaoImpl(); 
27         
28         try {
29             ///开始一个事务,start transaction;
30             //获取转入和转出的账户对象
31             TransactionManager.startTransaction();
32             
33             Account fromAccount=accountDao.findAccountByName(formName);
34             Account toAccount=accountDao.findAccountByName(toName);
35             
36             //修改账户的各自金额
37             fromAccount.setMoney(fromAccount.getMoney()-money);
38             toAccount.setMoney(toAccount.getMoney()+money);
39             
40             //完成转账的操作
41             accountDao.updateAccount(fromAccount);
42             
43             int i=2/0;
44             
45             accountDao.updateAccount(toAccount);
46               
47             TransactionManager.commitTransaction();
48             
49         } catch (Exception e) {
50             try {
51                 TransactionManager.rollbackTransaction();;//事务的回滚
52             } catch (Exception e2) {
53                 e2.printStackTrace();
54             }
55             
56         }finally{
57             try {
58                 TransactionManager.close();
59             } catch (Exception e2) {
60                 e2.printStackTrace();
61             }
62         }
63         
64         
65     }
66 
67     
68 }

第四步：测试类 TesTransfer

 1 package com.beiwo.epet.test;
 2 
 3 import org.junit.Test;
 4 
 5 import com.beiwo.epet.service.AccountService;
 6 import com.beiwo.epet.service.impl.AccountServiceImpl;
 7 
 8 public class TestTransfer {
 9 
10     
11     @Test
12     public void test(){
13         AccountService accountService=new AccountServiceImpl();
14         
15         accountService.transfer("aaa", "bbb", 100);
16         
17     }
18 }

数据库的建立：