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详解Spring MVC事务配置

程序员文章站 2024-03-01 08:53:22
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、annota...

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。