学习Spring框架，通过事务管理的方式搭建一个小的项目，该项目可以查询对数据库中的图书库存数量进行修改。
首先，使用MVC分层的设计模式思想搭建项目目录结构。
此部分代码源码之中都有相关注释，所以尽情附上源码。
首先Dao层的源码：
package com.jredu.book.Dao;
public interface BookDao {
/**
* 通过编号查询书的价格
* @param isbn
* @return
*/
int findBookPriceByIsbn(String isbn);
/**
* 通过用户名查询余额
* @param username
* @return
*/
int findBalanceByUsername(String username);
/**
* 更新书的库存
* @param isbn
*/
void updateBookStock(String isbn,int stock);
/**
* 通过编号查询库存数量
* @param isbn
* @return
*/
int findStockByIsbn(String isbn);
/**
* 更新用户余额信息
* @param username
* @param price
*/
void updateAccountBalance(String username,int price);
}
dao.impl相关的源码：
package com.jredu.book.Dao.Impl;
import java.util.Map;
import javax.sql.DataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;
import com.jredu.book.Dao.BookDao;
import com.jredu.book.entity.Account;
import com.jredu.book.entity.Book;
@Repository
public class BookDaoImpl extends JdbcDaoSupport implements BookDao{
@Autowired
public void setDS(DataSource dataSource){
setDataSource(dataSource);
}
@Override
public int findStockByIsbn(String isbn) {
// TODO Auto-generated method stub
String sql = "select * from book_stock where isbn=?";
Map<String, Object> bookStock= getJdbcTemplate().queryForMap(sql,isbn);
int stock = Integer.parseInt(bookStock.get("stock").toString());
return stock;
}
@Override
public int findBookPriceByIsbn(String isbn) {
// TODO Auto-generated method stub
String sql="select * from book where isbn=?";
Book book = getJdbcTemplate().queryForObject(sql, new Book(), isbn);
return book.getPrice();
}
@Override
public int findBalanceByUsername(String username) {
// TODO Auto-generated method stub
String sql = "select * from account where username=?";
Account account = getJdbcTemplate().queryForObject(sql, new Account(),username);
return account.getBalance();
}
@Override
public void updateBookStock(String isbn,int stock) {
// TODO Auto-generated method stub
String sql="update book_stock set stock=? where isbn=?";
getJdbcTemplate().update(sql,stock,isbn);
}
@Override
public void updateAccountBalance(String username, int price) {
// TODO Auto-generated method stub
String sql="update account set balance=? where username=?";
getJdbcTemplate().update(sql,price,username);
}
}
entity实体类的相关源码：
package com.jredu.book.entity;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
public class Account implements RowMapper<Account>{
private String username;
private int balance;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public int getBalance() {
return balance;
}
public void setBalance(int balance) {
this.balance = balance;
}
@Override
public Account mapRow(ResultSet rs, int arg1) throws SQLException {
// TODO Auto-generated method stub
Account account = new Account();
account.setUsername(rs.getString("username"));
account.setBalance(rs.getInt("balance"));
return account;
}
}
package com.jredu.book.entity;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
public class Book implements RowMapper<Book>{
private String isbn;
private String bookName;
private int price;
public String getIsbn() {
return isbn;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
public String getBookName() {
return bookName;
}
public void setBookName(String bookName) {
this.bookName = bookName;
}
public int getPrice() {
return price;
}
public void setPrice(int price) {
this.price = price;
}
@Override
public Book mapRow(ResultSet rs, int arg1) throws SQLException {
// TODO Auto-generated method stub
Book book = new Book();
book.setIsbn(rs.getString("isbn"));
book.setBookName(rs.getString("book_name"));
book.setPrice(rs.getInt("price"));
return book;
}
}
service目录下的相关源码：
package com.jredu.book.service;
public interface BookService {
void purchase(String isbn,String username);
}
package com.jredu.book.service;
public interface MoneyService {
void purchase(String isbn,String username);
}
service接口即service.impl目录下的相关源码：
package com.jredu.book.service.Impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import com.jredu.book.Dao.BookDao;
import com.jredu.book.service.BookService;
@Repository
public class BookServiceImpl implements BookService{
@Autowired
private BookDao dao;
@Override
public void purchase(String isbn, String username) {
// TODO Auto-generated method stub
int stock = dao.findStockByIsbn(isbn);
//库存要大于1本
if(stock>0){
int price = dao.findBookPriceByIsbn(isbn);
int balance = dao.findBalanceByUsername(username);
//余额是否大于书的价格
if(balance>=price){
//执行更新余额信息
dao.updateAccountBalance(username, balance-price);
//更新库存信息
dao.updateBookStock(isbn, stock-1);
}
}
}
}
编写一个测试类,book.test目录下测试类源码：
package com.jredu.book.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.jredu.book.service.BookService;
import com.jredu.book.service.MoneyService;
public class BookTest {
public static void main(String[] args) {
ApplicationContext app= new ClassPathXmlApplicationContext("applicationContext-book.xml");
BookService service = app.getBean(BookService.class);
service.purchase("abc","wang");
System.out.println("业务完成");
}
}
最重要的部分是配置application-book.xml的相关配置信息，相关注释代码之中含有，附上源码：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 自动扫描 -->
<context:component-scan base-package="com.jredu.book"></context:component-scan>
<!-- 配置C3P0数据源 -->
<!-- 导入资源文件 -->
<context:property-placeholder location="classpath:jdbc.properties"/>
<bean
id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
p:user="${jdbc.user}"
p:password="${jdbc.pwd}"
p:driverClass="${jdbc.driverClassName}"
p:jdbcUrl="${jdbc.url}"
p:initialPoolSize="${jdbc.initPoolSize}"
p:maxPoolSize="${jdbc.maxPoolSize}"
/>
<!-- 配置事务管理器 -->
<bean
id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="dataSource"
/>
<!-- 事务的通知 -->
<tx:advice
id="booktxAdvice" transaction-manager="transactionManager"
>
<tx:attributes>
<tx:method name="purchase*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
<aop:config>
<aop:pointcut expression="execution (* com.jredu.book.service.*.*(..))" id="pointcut"/>
<aop:advisor advice-ref="booktxAdvice" pointcut-ref="pointcut"/>
</aop:config>
<!-- 配置JDBC Template -->
<bean
id="jdbcTemplate"
class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource"
/>
</beans>至此，使用事务方式搭建的一个小项目就已经完成，操作完成后，数据库中的图书库存数量会有所变化。