Spring 事务详解

实现购买股票案例：

一、引入JAR文件：

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二、开始搭建分层架构---创建账户(Account)和股票(Stock)实体类

Account:

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/*  * 账户  */ public class Account {       private int aid;//账户编号     private String aname;//账户名称     private double balance;//账户金额                 public int getAid() {         return aid;     }     public void setAid(int aid) {         this.aid = aid;     }     public String getAname() {         return aname;     }     public void setAname(String aname) {         this.aname = aname;     }     public double getBalance() {         return balance;     }     public void setBalance(double balance) {         this.balance = balance;     }

Stock：　　

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/*  * 股票  */ public class Stock {   private int sid;//股票编号 private String sname;//名称 private int count;//股数     public int getSid() {     return sid; } public void setSid(int sid) {     this.sid = sid; } public String getSname() {     return sname; } public void setSname(String sname) {     this.sname = sname; } public int getCount() {     return count; } public void setCount(int count) {     this.count = count; } }

三、创建Dao层，定义账户以及股票的接口，自定义新增和修改的方法，实现类实现该接口，重写方法　　

IAccountDao：

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public interface IAccountDao {     //添加账户     public int addAccount(Account account);          //修改账户     public int updateAccount(int aid,int money,boolean isBuyOrNot);<br>

//查询余额
     public int selectMoney(int aid);

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}

IStockDao：　　

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public interface IStockDao {   //添加股票   public int addStock(Stock stock);             //修改股票   public int updateStock(int aid,int num,boolean isBuyOrNot); }

AccountDaoImpl:实现类。继承自JdbcDaoSupport并实现IAccountDao接口，在这里需要用到JDBC模板的getJdbcTemplate()，通过该方法实现对SQL语句增删改查。

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public class AccountDaoImpl extends JdbcDaoSupport implements IAccountDao{       //添加     public int addAccount(Account account) {         String sql="insert into account(aid,aname,balance) values(?,?,?)";         int count=this.getJdbcTemplate().update(sql, account.getAid(),account.getAname(),account.getBalance());         return count;     }       //修改     public int updateAccount(int aid, int money, boolean isBuyOrNot) {         String sql=null;         if(isBuyOrNot){             sql="update account set balance=balance-? where aid=?";         }         else{             sql="update account set balance=balance+? where aid=?";         }         int count=this.getJdbcTemplate().update(sql, money,aid);         return count;     }

StockDaoImpl：实现类同理

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public class StockDaoImpl extends JdbcDaoSupport implements IStockDao{       //添加股票     public int addStock(Stock stock) {         String sql="insert into stock(sid,sname,count) values(?,?,?)";         int count=this.getJdbcTemplate().update(sql, stock.getSid(),stock.getSname(),stock.getCount());         return count;     }       //修改     public int updateStock(int aid, int num, boolean isBuyOrNot) {         String sql=null;         if(isBuyOrNot){             sql="update stock set count=count+? where sid=?";         }         else{             sql="update stock set count=count-? where sid=?";         }         int count=this.getJdbcTemplate().update(sql, num,aid);         return count;           }

四、业务逻辑层：service　　

定义接口IStockService,并实现添加账户，股票，以及购买股票的方法.购买股票需要传入账户的id,股票的id。以及金额，股数

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public interface IStockService {        //添加账户     public int addAccount(Account account);     //添加股票     public int addStock(Stock stock);           //购买股票     public void buyStock(int aid,int money,int sid,int num) throws StockException; }

实现类：StockServiceImpl。重写方法。并植入Dao。以及自定义StockException异常，用于判定用户的余额小于0，抛出异常

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public class StockServiceImpl implements IStockService{        //植入dao     private IAccountDao accountDao;     private IStockDao stockDao;     //添加账户     public int addAccount(Account account) {                   return accountDao.addAccount(account);     }        //添加股票     public int addStock(Stock stock) {         return stockDao.addStock(stock);     }       //购买一股票     public void buyStock(int aid, int money, int sid, int num) throws StockException {           boolean isBuy=true;         accountDao.updateAccount(aid, money, isBuy);         if(accountDao.selectMoney(aid)<=0){             throw new StockException("捕获异常！！！");         }                   stockDao.updateStock(aid, num, isBuy);               }

五、Spring配置文件。[重点]

方式一:通过事务代理工厂bean进行配置[XML方式]

①引入一系列的约束头文件以及标签

②配置C3P0数据源以及DAO、Service　　

③配置事务管理器以及事务代理工厂Bean。测试类getBean获取的是代理工厂id

　

方式二：注解。测试类getBean获取的id是原始对象service

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方式三：Aspectj AOP配置事务 。同理 测试类getBean方法id获取的是原始对象

测试类：

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public class Test01 { @Test public void addTest() throws StockException{     ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext.xml");           IStockService service = (IStockService)ctx.getBean("stockService");           service.buyStock(1, 800, 1, 2); }