Spring 教程04

spring-4
1.    Xml

<!-- \src\applicationContext-tx-xml.xml -->
<?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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.atguigu.spring"></context:component-scan>

    <!-- 导入资源文件 -->
    <context:property-placeholder location="classpath:db.properties"/>

    <!-- 配置 C3P0 数据源 -->
    <bean id="dataSource"
        class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>

        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
    </bean>

    <!-- 配置 Spirng 的 JdbcTemplate -->
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 配置 bean -->
    <bean id="bookShopDao" class="com.atguigu.spring.tx.xml.BookShopDaoImpl">
        <property name="jdbcTemplate" ref="jdbcTemplate"></property>
    </bean>

    <bean id="bookShopService" class="com.atguigu.spring.tx.xml.service.impl.BookShopServiceImpl">
        <property name="bookShopDao" ref="bookShopDao"></property>
    </bean>

    <bean id="cashier" class="com.atguigu.spring.tx.xml.service.impl.CashierImpl">
        <property name="bookShopService" ref="bookShopService"></property>
    </bean>

    <!-- 1. 配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 2. 配置事务属性 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <!-- 根据方法名指定事务的属性 -->
            <tx:method name="purchase" propagation="REQUIRES_NEW"/>
            <tx:method name="get*" read-only="true"/>
            <tx:method name="find*" read-only="true"/>
            <tx:method name="*"/>
        </tx:attributes>
    </tx:advice>

    <!-- 3. 配置事务切入点, 以及把事务切入点和事务属性关联起来 -->
    <aop:config>
        <aop:pointcut expression="execution(* com.atguigu.spring.tx.xml.service.*.*(..))"
            id="txPointCut"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="txPointCut"/>
    </aop:config>

</beans>

<!-- \src\applicationContext.xml -->
<?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:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <context:component-scan base-package="com.atguigu.spring"></context:component-scan>

    <!-- 导入资源文件 -->
    <context:property-placeholder location="classpath:db.properties"/>

    <!-- 配置 C3P0 数据源 -->
    <bean id="dataSource"
        class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>

        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
    </bean>

    <!-- 配置 Spirng 的 JdbcTemplate -->
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 配置 NamedParameterJdbcTemplate, 该对象可以使用具名参数, 其没有无参数的构造器, 所以必须为其构造器指定参数 -->
    <bean id="namedParameterJdbcTemplate"
        class="org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate">
        <constructor-arg ref="dataSource"></constructor-arg>
    </bean>

    <!-- 配置事务管理器 -->
    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 启用事务注解 -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

2.    Properties

# \src\db.properties
jdbc.user=root
jdbc.password=1230
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///spring

jdbc.initPoolSize=5
jdbc.maxPoolSize=10
3.    Java

// \src\com\atguigu\spring\jdbc\Department.java
package com.atguigu.spring.jdbc;

public class Department {

    private Integer id;
    private String name;

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    @Override
    public String toString() {
        return "Department [id=" + id + ", name=" + name + "]";
    }

}

// \src\com\atguigu\spring\jdbc\DepartmentDao.java
package com.atguigu.spring.jdbc;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;

/**
 * 不推荐使用 JdbcDaoSupport, 而推荐直接使用 JdbcTempate 作为 Dao 类的成员变量
 */
@Repository
public class DepartmentDao extends JdbcDaoSupport{

    @Autowired
    public void setDataSource2(DataSource dataSource){
        setDataSource(dataSource);
    }

    public Department get(Integer id){
        String sql = "SELECT id, dept_name name FROM departments WHERE id = ?";
        RowMapper<Department> rowMapper = new BeanPropertyRowMapper<>(Department.class);
        return getJdbcTemplate().queryForObject(sql, rowMapper, id);
    }

}

// \src\com\atguigu\spring\jdbc\Employee.java
package com.atguigu.spring.jdbc;

public class Employee {

    private Integer id;
    private String lastName;
    private String email;

    private Integer dpetId;

    public Integer getId() {
        return id;
    }

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

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getDpetId() {
        return dpetId;
    }

    public void setDpetId(Integer dpetId) {
        this.dpetId = dpetId;
    }

    @Override
    public String toString() {
        return "Employee [id=" + id + ", lastName=" + lastName + ", email="
                + email + ", dpetId=" + dpetId + "]";
    }

}

// \src\com\atguigu\spring\jdbc\EmployeeDao.java
package com.atguigu.spring.jdbc;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Repository;

@Repository
public class EmployeeDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    public Employee get(Integer id){
        String sql = "SELECT id, last_name lastName, email FROM employees WHERE id = ?";
        RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
        Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, id);

        return employee;
    }
}

// \src\com\atguigu\spring\jdbc\JDBCTest.java
package com.atguigu.spring.jdbc;

import java.sql.SQLException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.sql.DataSource;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.BeanPropertySqlParameterSource;
import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
import org.springframework.jdbc.core.namedparam.SqlParameterSource;

public class JDBCTest {

    private ApplicationContext ctx = null;
    private JdbcTemplate jdbcTemplate;
    private EmployeeDao employeeDao;
    private DepartmentDao departmentDao;
    private NamedParameterJdbcTemplate namedParameterJdbcTemplate;

    {
        ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        jdbcTemplate = (JdbcTemplate) ctx.getBean("jdbcTemplate");
        employeeDao = ctx.getBean(EmployeeDao.class);
        departmentDao = ctx.getBean(DepartmentDao.class);
        namedParameterJdbcTemplate = ctx.getBean(NamedParameterJdbcTemplate.class);
    }

    /**
     * 使用具名参数时, 可以使用 update(String sql, SqlParameterSource paramSource) 方法进行更新操作
     * 1. SQL 语句中的参数名和类的属性一致!
     * 2. 使用 SqlParameterSource 的 BeanPropertySqlParameterSource 实现类作为参数.
     */
    @Test
    public void testNamedParameterJdbcTemplate2(){
        String sql = "INSERT INTO employees(last_name, email, dept_id) "
                + "VALUES(:lastName,:email,:dpetId)";

        Employee employee = new Employee();
        employee.setLastName("XYZ");
        employee.setEmail("[email protected]");
        employee.setDpetId(3);

        SqlParameterSource paramSource = new BeanPropertySqlParameterSource(employee);
        namedParameterJdbcTemplate.update(sql, paramSource);
    }

    /**
     * 可以为参数起名字.
     * 1. 好处: 若有多个参数, 则不用再去对应位置, 直接对应参数名, 便于维护
     * 2. 缺点: 较为麻烦.
     */
    @Test
    public void testNamedParameterJdbcTemplate(){
        String sql = "INSERT INTO employees(last_name, email, dept_id) VALUES(:ln,:email,:deptid)";

        Map<String, Object> paramMap = new HashMap<>();
        paramMap.put("ln", "FF");
        paramMap.put("email", "[email protected]");
        paramMap.put("deptid", 2);

        namedParameterJdbcTemplate.update(sql, paramMap);
    }

    @Test
    public void testDepartmentDao(){
        System.out.println(departmentDao.get(1));
    }

    @Test
    public void testEmployeeDao(){
        System.out.println(employeeDao.get(1));
    }

    /**
     * 获取单个列的值, 或做统计查询
     * 使用 queryForObject(String sql, Class<Long> requiredType)
     */
    @Test
    public void testQueryForObject2(){
        String sql = "SELECT count(id) FROM employees";
        long count = jdbcTemplate.queryForObject(sql, Long.class);

        System.out.println(count);
    }

    /**
     * 查到实体类的集合
     * 注意调用的不是 queryForList 方法
     */
    @Test
    public void testQueryForList(){
        String sql = "SELECT id, last_name lastName, email FROM employees WHERE id > ?";
        RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
        List<Employee> employees = jdbcTemplate.query(sql, rowMapper,5);

        System.out.println(employees);
    }

    /**
     * 从数据库中获取一条记录, 实际得到对应的一个对象
     * 注意不是调用 queryForObject(String sql, Class<Employee> requiredType, Object... args) 方法!
     * 而需要调用 queryForObject(String sql, RowMapper<Employee> rowMapper, Object... args)
     * 1. 其中的 RowMapper 指定如何去映射结果集的行, 常用的实现类为 BeanPropertyRowMapper
     * 2. 使用 SQL 中列的别名完成列名和类的属性名的映射. 例如 last_name lastName
     * 3. 不支持级联属性. JdbcTemplate 到底是一个 JDBC 的小工具, 而不是 ORM 框架
     */
    @Test
    public void testQueryForObject(){
        String sql = "SELECT id, last_name lastName, email, dept_id as \"department.id\" FROM employees WHERE id = ?";
        RowMapper<Employee> rowMapper = new BeanPropertyRowMapper<>(Employee.class);
        Employee employee = jdbcTemplate.queryForObject(sql, rowMapper, 1);

        System.out.println(employee);
    }

    /**
     * 执行批量更新: 批量的 INSERT, UPDATE, DELETE
     * 最后一个参数是 Object[] 的 List 类型: 因为修改一条记录需要一个 Object 的数组, 那么多条不就需要多个 Object 的数组吗
     */
    @Test
    public void testBatchUpdate(){
        String sql = "INSERT INTO employees(last_name, email, dept_id) VALUES(?,?,?)";

        List<Object[]> batchArgs = new ArrayList<>();

        batchArgs.add(new Object[]{"AA", "[email protected]", 1});
        batchArgs.add(new Object[]{"BB", "[email protected]", 2});
        batchArgs.add(new Object[]{"CC", "[email protected]", 3});
        batchArgs.add(new Object[]{"DD", "[email protected]", 3});
        batchArgs.add(new Object[]{"EE", "[email protected]", 2});

        jdbcTemplate.batchUpdate(sql, batchArgs);
    }

    /**
     * 执行 INSERT, UPDATE, DELETE
     */
    @Test
    public void testUpdate(){
        String sql = "UPDATE employees SET last_name = ? WHERE id = ?";
        jdbcTemplate.update(sql, "Jack", 5);
    }

    @Test
    public void testDataSource() throws SQLException {
        DataSource dataSource = ctx.getBean(DataSource.class);
        System.out.println(dataSource.getConnection());
    }

}

// \src\com\atguigu\spring\tx\BookShopDao.java
package com.atguigu.spring.tx;

public interface BookShopDao {

    //根据书号获取书的单价
    public int findBookPriceByIsbn(String isbn);

    //更新数的库存. 使书号对应的库存 - 1
    public void updateBookStock(String isbn);

    //更新用户的账户余额: 使 username 的 balance - price
    public void updateUserAccount(String username, int price);
}

// \src\com\atguigu\spring\tx\BookShopDaoImpl.java
package com.atguigu.spring.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;

@Repository("bookShopDao")
public class BookShopDaoImpl implements BookShopDao {

    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Override
    public int findBookPriceByIsbn(String isbn) {
        String sql = "SELECT price FROM book WHERE isbn = ?";
        return jdbcTemplate.queryForObject(sql, Integer.class, isbn);
    }

    @Override
    public void updateBookStock(String isbn) {
        //检查书的库存是否足够, 若不够, 则抛出异常
        String sql2 = "SELECT stock FROM book_stock WHERE isbn = ?";
        int stock = jdbcTemplate.queryForObject(sql2, Integer.class, isbn);
        if(stock == 0){
            throw new BookStockException("库存不足!");
        }

        String sql = "UPDATE book_stock SET stock = stock -1 WHERE isbn = ?";
        jdbcTemplate.update(sql, isbn);
    }

    @Override
    public void updateUserAccount(String username, int price) {
        //验证余额是否足够, 若不足, 则抛出异常
        String sql2 = "SELECT balance FROM account WHERE username = ?";
        int balance = jdbcTemplate.queryForObject(sql2, Integer.class, username);
        if(balance < price){
            throw new UserAccountException("余额不足!");
        }

        String sql = "UPDATE account SET balance = balance - ? WHERE username = ?";
        jdbcTemplate.update(sql, price, username);
    }

}

// \src\com\atguigu\spring\tx\BookShopService.java
package com.atguigu.spring.tx;

public interface BookShopService {

    public void purchase(String username, String isbn);

}

// \src\com\atguigu\spring\tx\BookShopServiceImpl.java
package com.atguigu.spring.tx;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

@Service("bookShopService")
public class BookShopServiceImpl implements BookShopService {

    @Autowired
    private BookShopDao bookShopDao;

    //添加事务注解
    //1.使用 propagation 指定事务的传播行为, 即当前的事务方法被另外一个事务方法调用时
    //如何使用事务, 默认取值为 REQUIRED, 即使用调用方法的事务
    //REQUIRES_NEW: 事务自己的事务, 调用的事务方法的事务被挂起.
    //2.使用 isolation 指定事务的隔离级别, 最常用的取值为 READ_COMMITTED
    //3.默认情况下 Spring 的声明式事务对所有的运行时异常进行回滚. 也可以通过对应的
    //属性进行设置. 通常情况下去默认值即可.
    //4.使用 readOnly 指定事务是否为只读. 表示这个事务只读取数据但不更新数据,
    //这样可以帮助数据库引擎优化事务. 若真的事一个只读取数据库值的方法, 应设置 readOnly=true
    //5.使用 timeout 指定强制回滚之前事务可以占用的时间.
//  @Transactional(propagation=Propagation.REQUIRES_NEW,
//          isolation=Isolation.READ_COMMITTED,
//          noRollbackFor={UserAccountException.class})
    @Transactional(propagation=Propagation.REQUIRES_NEW,
            isolation=Isolation.READ_COMMITTED,
            readOnly=false,
            timeout=3)
    @Override
    public void purchase(String username, String isbn) {

        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {}

        //1. 获取书的单价
        int price = bookShopDao.findBookPriceByIsbn(isbn);

        //2. 更新数的库存
        bookShopDao.updateBookStock(isbn);

        //3. 更新用户余额
        bookShopDao.updateUserAccount(username, price);
    }

}

// \src\com\atguigu\spring\tx\BookStockException.java
package com.atguigu.spring.tx;

public class BookStockException extends RuntimeException{

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    public BookStockException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message, Throwable cause,
            boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

}

// \src\com\atguigu\spring\tx\Cashier.java
package com.atguigu.spring.tx;

import java.util.List;

public interface Cashier {

    public void checkout(String username, List<String> isbns);

}

// \src\com\atguigu\spring\tx\CashierImpl.java
package com.atguigu.spring.tx;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service("cashier")
public class CashierImpl implements Cashier {

    @Autowired
    private BookShopService bookShopService;

    @Transactional
    @Override
    public void checkout(String username, List<String> isbns) {
        for(String isbn: isbns){
            bookShopService.purchase(username, isbn);
        }
    }

}

// \src\com\atguigu\spring\tx\SpringTransactionTest.java
package com.atguigu.spring.tx;

import static org.junit.Assert.*;

import java.util.Arrays;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class SpringTransactionTest {

    private ApplicationContext ctx = null;
    private BookShopDao bookShopDao = null;
    private BookShopService bookShopService = null;
    private Cashier cashier = null;

    {
        ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        bookShopDao = ctx.getBean(BookShopDao.class);
        bookShopService = ctx.getBean(BookShopService.class);
        cashier = ctx.getBean(Cashier.class);
    }

    @Test
    public void testTransactionlPropagation(){
        cashier.checkout("AA", Arrays.asList("1001", "1002"));
    }

    @Test
    public void testBookShopService(){
        bookShopService.purchase("AA", "1001");
    }

    @Test
    public void testBookShopDaoUpdateUserAccount(){
        bookShopDao.updateUserAccount("AA", 200);
    }

    @Test
    public void testBookShopDaoUpdateBookStock(){
        bookShopDao.updateBookStock("1001");
    }

    @Test
    public void testBookShopDaoFindPriceByIsbn() {
        System.out.println(bookShopDao.findBookPriceByIsbn("1001"));
    }

}

// \src\com\atguigu\spring\tx\UserAccountException.java
package com.atguigu.spring.tx;

public class UserAccountException extends RuntimeException{

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    public UserAccountException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message, Throwable cause,
            boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

}

// \src\com\atguigu\spring\tx\xml\BookShopDao.java
package com.atguigu.spring.tx.xml;

public interface BookShopDao {

    //根据书号获取书的单价
    public int findBookPriceByIsbn(String isbn);

    //更新数的库存. 使书号对应的库存 - 1
    public void updateBookStock(String isbn);

    //更新用户的账户余额: 使 username 的 balance - price
    public void updateUserAccount(String username, int price);
}

// \src\com\atguigu\spring\tx\xml\BookShopDaoImpl.java
package com.atguigu.spring.tx.xml;

import org.springframework.jdbc.core.JdbcTemplate;

public class BookShopDaoImpl implements BookShopDao {

    private JdbcTemplate jdbcTemplate;

    public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
        this.jdbcTemplate = jdbcTemplate;
    }

    @Override
    public int findBookPriceByIsbn(String isbn) {
        String sql = "SELECT price FROM book WHERE isbn = ?";
        return jdbcTemplate.queryForObject(sql, Integer.class, isbn);
    }

    @Override
    public void updateBookStock(String isbn) {
        //检查书的库存是否足够, 若不够, 则抛出异常
        String sql2 = "SELECT stock FROM book_stock WHERE isbn = ?";
        int stock = jdbcTemplate.queryForObject(sql2, Integer.class, isbn);
        if(stock == 0){
            throw new BookStockException("库存不足!");
        }

        String sql = "UPDATE book_stock SET stock = stock -1 WHERE isbn = ?";
        jdbcTemplate.update(sql, isbn);
    }

    @Override
    public void updateUserAccount(String username, int price) {
        //验证余额是否足够, 若不足, 则抛出异常
        String sql2 = "SELECT balance FROM account WHERE username = ?";
        int balance = jdbcTemplate.queryForObject(sql2, Integer.class, username);
        if(balance < price){
            throw new UserAccountException("余额不足!");
        }

        String sql = "UPDATE account SET balance = balance - ? WHERE username = ?";
        jdbcTemplate.update(sql, price, username);
    }

}

// \src\com\atguigu\spring\tx\xml\BookStockException.java
package com.atguigu.spring.tx.xml;

public class BookStockException extends RuntimeException{

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    public BookStockException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message, Throwable cause,
            boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public BookStockException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

}

// \src\com\atguigu\spring\tx\xml\service\BookShopService.java
package com.atguigu.spring.tx.xml.service;

public interface BookShopService {

    public void purchase(String username, String isbn);

}

// \src\com\atguigu\spring\tx\xml\service\Cashier.java
package com.atguigu.spring.tx.xml.service;

import java.util.List;

public interface Cashier {

    public void checkout(String username, List<String> isbns);

}

// \src\com\atguigu\spring\tx\xml\service\impl\BookShopServiceImpl.java
package com.atguigu.spring.tx.xml.service.impl;

import com.atguigu.spring.tx.xml.BookShopDao;
import com.atguigu.spring.tx.xml.service.BookShopService;

public class BookShopServiceImpl implements BookShopService {

    private BookShopDao bookShopDao;

    public void setBookShopDao(BookShopDao bookShopDao) {
        this.bookShopDao = bookShopDao;
    }

    @Override
    public void purchase(String username, String isbn) {

        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {}

        //1. 获取书的单价
        int price = bookShopDao.findBookPriceByIsbn(isbn);

        //2. 更新数的库存
        bookShopDao.updateBookStock(isbn);

        //3. 更新用户余额
        bookShopDao.updateUserAccount(username, price);
    }

}

// \src\com\atguigu\spring\tx\xml\service\impl\CashierImpl.java
package com.atguigu.spring.tx.xml.service.impl;

import java.util.List;

import com.atguigu.spring.tx.xml.service.BookShopService;
import com.atguigu.spring.tx.xml.service.Cashier;

public class CashierImpl implements Cashier {

    private BookShopService bookShopService;

    public void setBookShopService(BookShopService bookShopService) {
        this.bookShopService = bookShopService;
    }

    @Override
    public void checkout(String username, List<String> isbns) {
        for(String isbn: isbns){
            bookShopService.purchase(username, isbn);
        }
    }

}

// \src\com\atguigu\spring\tx\xml\SpringTransactionTest.java
package com.atguigu.spring.tx.xml;

import java.util.Arrays;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.atguigu.spring.tx.xml.service.BookShopService;
import com.atguigu.spring.tx.xml.service.Cashier;

public class SpringTransactionTest {

    private ApplicationContext ctx = null;
    private BookShopDao bookShopDao = null;
    private BookShopService bookShopService = null;
    private Cashier cashier = null;

    {
        ctx = new ClassPathXmlApplicationContext("applicationContext-tx-xml.xml");
        bookShopDao = ctx.getBean(BookShopDao.class);
        bookShopService = ctx.getBean(BookShopService.class);
        cashier = ctx.getBean(Cashier.class);
    }

    @Test
    public void testTransactionlPropagation(){
        cashier.checkout("AA", Arrays.asList("1001", "1002"));
    }

    @Test
    public void testBookShopService(){
        bookShopService.purchase("AA", "1001");
    }

}

// \src\com\atguigu\spring\tx\xml\UserAccountException.java
package com.atguigu.spring.tx.xml;

public class UserAccountException extends RuntimeException{

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    public UserAccountException() {
        super();
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message, Throwable cause,
            boolean enableSuppression, boolean writableStackTrace) {
        super(message, cause, enableSuppression, writableStackTrace);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message, Throwable cause) {
        super(message, cause);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(String message) {
        super(message);
        // TODO Auto-generated constructor stub
    }

    public UserAccountException(Throwable cause) {
        super(cause);
        // TODO Auto-generated constructor stub
    }

}
时间： 2024-12-23 03:11:04

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