详解Spring MVC事务配置

发布时间：2020-08-28 22:34:21 来源：脚本之家阅读：205 作者：leiOOlei 栏目：编程语言

要了解事务配置的所有方法，请看一下《Spring事务配置的5种方法》

本文介绍两种配置方法：

一、XML，使用tx标签配置拦截器实现事务

二、Annotation方式

以下所使用环境为Spring4.0.3、Hibernate4.3.5

一、 XML，使用tx标签配置拦截器实现事务

Entity类User.java，持久化类，对应数据库表user

package com.lei.demo.entity;

import javax.persistence.*;

@Entity(name="users")
public class Users {
  
  public Users(){
    super();
  }
  
  @Id
  @GeneratedValue(strategy=GenerationType.AUTO)
  @Column(name="id")
  private Integer id;
  
  @Column(name="user_name",length=32)
  private String user_name;
  
  @Column(name="age")
  private Integer age;
  
  @Column(name="nice_name",length=32)
  private String nice_name;
  
  //属性实现......

}

UserDAO.javar，表user的一些操作，其中属性sessionFactory应该由Spring注入，如下：

package com.lei.demo.dao;

import java.util.List;

import javax.annotation.Resource;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;

import com.lei.demo.entity.Users;

public class UsersDAO {
  private SessionFactory sessionFactory;

  public void setSessionFactory(SessionFactory sessionFactory) {
    this.sessionFactory = sessionFactory;
  }

  public SessionFactory getSessionFactory() {
    return sessionFactory;
  }

  public List<Users> getAllUser(){
    String hsql="from users";
    Session session = sessionFactory.getCurrentSession();
    Query query = session.createQuery(hsql);
    
    return query.list();
  }
}

UserService.java，业务实现类，如下

package com.lei.demo.service;

import javax.annotation.Resource;

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

import com.lei.demo.dao.*;

public class UserService {
  private UsersDAO userDao;
  
  public int userCount(){
    return userDao.getAllUser().size();
  }

  public UsersDAO getUserDao() {
    return userDao;
  }

  public void setUserDao(UsersDAO userDao) {
    this.userDao = userDao;
  }

}

首先看一下xml配置，spring-hibernate.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xsi:schemaLocation="
    http://www.springframework.org/schema/beans   
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    ">

  <!-- Hibernate4 -->
  <!-- 加载资源文件 其中包含变量信息，必须在Spring配置文件的最前面加载，即第一个加载-->
  <context:property-placeholder location="classpath:persistence-mysql.properties" />
  
  <bean id="sessionFactory" 
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan">
      <list>
        <!-- 可以加多个包 -->
        <value>com.lei.demo.entity</value>
      </list>
    </property>
    <property name="hibernateProperties">
      <props>
        <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
        <prop key="hibernate.dialect">${hibernate.dialect}</prop>
        <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
        <!-- <prop key="hibernate.current_session_context_class">thread</prop> --> 
      </props>
    </property>
  </bean>
  
  <!-- 数据库映射 -->
  <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
   <property name="driverClassName" value="${jdbc.driverClassName}" />
   <property name="url" value="${jdbc.url}" />
   <property name="username" value="${jdbc.user}" />
   <property name="password" value="${jdbc.pass}" />
  </bean>
  
  <!-- 配置Hibernate事务管理器 -->
  <bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
   <property name="sessionFactory" ref="sessionFactory" />
  </bean>
  
  <!-- 配置事务异常封装 -->
  <bean id="persistenceExceptionTranslationPostProcessor" 
    class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />
  
  <!-- 声明式容器事务管理 ,transaction-manager指定事务管理器为transactionManager -->
  <tx:advice id="txAdvice" transaction-manager="transactionManager">
    <tx:attributes>
      <tx:method name="add*" propagation="REQUIRED" />
      <tx:method name="get*" propagation="REQUIRED" />
      <tx:method name="*" read-only="true" />
    </tx:attributes>
  </tx:advice>
  
  <aop:config expose-proxy="true">
    <!-- 只对业务逻辑层实施事务 -->
    <aop:pointcut id="txPointcut" expression="execution(* com.lei.demo.service..*.*(..))" />
    <!-- Advisor定义，切入点和通知分别为txPointcut、txAdvice -->
    <aop:advisor pointcut-ref="txPointcut" advice-ref="txAdvice"/>
  </aop:config>
  
</beans>

其中主要配置中是tx:advice和aop:config两个配置节，以Spring AOP的方式实现事务管理。

tx:advice配置了事务的管理者是transactionManager，同时tx:method也规定了如果方法名匹配“add*”和“get*”方法时使用事务，propagation是设定事务的传播级别。除了“add*”和“get*”方法，其他的方法的事务是只读的（典型地，对于只执行查询的事务你会将该属性设为true，如果出现了更新、插入或是删除语句时只读事务就会失败）

aop:config指定了一个aop:pointcut去引用上边的advice。

这样就通过AOP的拦截机制实现了事务，当然你还要用Spring的方式自己配置UserDAO和UserService。

二、Annotation方式

第一步，首先看一下web.xml，如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xmlns="http://java.sun.com/xml/ns/javaee" 
  xmlns:web="http://java.sun.com/xml/ns/javaee" 
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
    id="WebApp_ID" version="3.0">
 <display-name>Archetype Created Web Application</display-name>
 <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:/spring-*.xml</param-value>
 </context-param>
 <listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>
 <servlet>
  <servlet-name>lei-dispatcher</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <init-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>classpath:/lei-dispatcher-servlet.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
  <servlet-name>lei-dispatcher</servlet-name>
  <url-pattern>/</url-pattern>
 </servlet-mapping>
</web-app>

第二步，spring-hibernate配置，见以下spring-hibernate.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xsi:schemaLocation="
    http://www.springframework.org/schema/beans   
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    ">

  <!-- Hibernate4 -->
  <!-- 加载资源文件 其中包含变量信息，必须在Spring配置文件的最前面加载，即第一个加载-->
  <context:property-placeholder location="classpath:persistence-mysql.properties" />
  
  <bean id="sessionFactory" 
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan">
      <list>
        <!-- 可以加多个包 -->
        <value>com.lei.demo.entity</value>
      </list>
    </property>
    <property name="hibernateProperties">
      <props>
        <prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
        <prop key="hibernate.dialect">${hibernate.dialect}</prop>
        <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
        <!-- <prop key="hibernate.current_session_context_class">thread</prop> --> 
      </props>
    </property>
  </bean>
  
  <!-- 数据库映射 -->
  <!-- class="org.apache.tomcat.dbcp.dbcp.BasicDataSource" -->
  <!-- class="org.springframework.jdbc.datasource.DriverManagerDataSource" -->
  <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
   <property name="driverClassName" value="${jdbc.driverClassName}" />
   <property name="url" value="${jdbc.url}" />
   <property name="username" value="${jdbc.user}" />
   <property name="password" value="${jdbc.pass}" />
  </bean>
  
  <!-- 配置Hibernate事务管理器 -->
  <bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
   <property name="sessionFactory" ref="sessionFactory" />
  </bean>
  
  <!-- 配置事务异常封装 -->
  <bean id="persistenceExceptionTranslationPostProcessor" 
    class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

</beans>

第一节中xml配置事务中需要通过配置tx:advice和aop:config来增加事务的功能。此处采用全注释方法，这两个配置节就不需要了。

相应的需要在视图解析配置中启用注释，如下lei-dispatcher-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:mvc="http://www.springframework.org/schema/mvc"
  xmlns:p="http://www.springframework.org/schema/p"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xsi:schemaLocation="
    http://www.springframework.org/schema/beans   
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    http://www.springframework.org/schema/tx
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    ">
    
  <!-- 启动自动扫描 该包下所有的Bean(@Controller) -->
  <context:component-scan base-package="com.lei.demo" />
  
  <!-- 基于注释的事务，当注释中发现@Transactional时，使用id为“transactionManager”的事务管理器 -->
  <!-- 如果没有设置transaction-manager的值，则spring以缺省默认的事务管理器来处理事务，默认事务管理器为第一个加载的事务管理器 -->
  <tx:annotation-driven transaction-manager="transactionManager"/>
  
  <!-- 定义视图解析器 -->
  <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="prefix">
      <value>/WEB-INF/user/</value>
    </property>
    <property name="suffix">
      <value>.jsp</value>
    </property>
  </bean>
  
</beans>

UserDAO如下

package com.lei.demo.dao;

import java.util.List;

import javax.annotation.Resource;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.stereotype.Repository;

import com.lei.demo.entity.Users;

@Repository
public class UsersDAO {
  @Resource(name="sessionFactory")
  private SessionFactory sessionFactory;

  public void setSessionFactory(SessionFactory sessionFactory) {
    this.sessionFactory = sessionFactory;
  }

  public SessionFactory getSessionFactory() {
    return sessionFactory;
  }

  public List<Users> getAllUser(){
    String hsql="from users";
    Session session = sessionFactory.getCurrentSession();
    Query query = session.createQuery(hsql);
    
    return query.list();
  }
}

UserService.java如下

package com.lei.demo.service;

import javax.annotation.Resource;

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

import com.lei.demo.dao.*;

@Service("userService")
public class UserService {
  @Resource
  private UsersDAO userDao;
  
  @Transactional
  public int userCount(){
    return userDao.getAllUser().size();
  }

  public UsersDAO getUserDao() {
    return userDao;
  }

  public void setUserDao(UsersDAO userDao) {
    this.userDao = userDao;
  }

}

这里，方法名userCount上加入@Transactional，说明这个方法要启用事务。如果类名UserService上加入@Transactional，则表明这个类中的所有方法都会启用事务。

如果配有多个transactionManager，例如配置有transactionManager1,和transactionManager2，则可以通过@Transactional(“transactionManager1”)，的方式指定使用哪个数据源的事务。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持亿速云。

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