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Spring事务之详解--三种实现方式
实现购买股票案例:
一、引入JAR文件:
二、开始搭建分层架构---创建账户(Account)和股票(Stock)实体类
Account:
/* * 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:
/* * 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:
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);
//查询余额
public int selectMoney(int aid);
}
IStockDao:
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。
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
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
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
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
<!-- 注解 --> <tx:annotation-driven transaction-manager="mytx"/>
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:
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); }
Spring事务之详解--三种实现方式