SSH第一篇【整合SSH步骤、OpenSessionInView】

前言

到目前为止，Struts2、Hibernate、Spring框架都过了一遍了。也写过了Spring怎么与Struts2整合，Spring与Hibernate整合…本博文主要讲解SSH的整合

整合步骤：

• 1） 引入SSH Jar文件
  
  • Struts 核心jar
  • Hibernate 核心jar
  • Spring
    
    • Core 核心功能
    • Web 对web模块支持
    • Aop aop支持
    • Orm 对hibernate支持
    • Jdbc/tx jdbc支持包、事务相关包
• 2）配置文件
  
  • Web.xml
    
    • 初始化struts功能、spring容器
  • Struts.xml 配置请求路径与映射action的关系
  • Spring.xml IOC容器配置
  • bean-base.xml 【公用信息】
  • bean-service.xml
  • bean-dao.xml
  • bean-action.xml

需求：员工与部门之间的关系。当操作员工的时候，可以得到员工所在的部门

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引入jar文件

配置文件

web.xml配置文件

初始化struts功能、spring容器

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"         version="3.1">    <!--初始化Struts功能-->    <filter>        <filter-name>struts2</filter-name>        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>struts2</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>    <!--初始化Spring容器-->    <!-- 2. spring 配置 -->    <context-param>        <param-name>contextConfigLocation</param-name>        <param-value>/WEB-INF/classes/bean*</param-value>    </context-param>    <listener>        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>    </listener></web-app>

Struts.xml

配置请求路径与映射action的关系【记得继承着struts-default】

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE struts PUBLIC        "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"        "http://struts.apache.org/dtds/struts-2.3.dtd"><struts>    <package name="aaa" extends="struts-default">    </package></struts>

SpringIOC容器配置

该Spring配置文件配置着一些公用的信息

<?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:tx="http://www.springframework.org/schema/tx"       xmlns:aop="http://www.springframework.org/schema/aop"       xmlns:context="http://www.springframework.org/schema/context"       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.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">    <!-- 1) 连接池实例 -->    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>        <property name="jdbcUrl" value="jdbc:mysql:///zhongfucheng"></property>        <property name="user" value="root"></property>        <property name="password" value="root"></property>        <property name="initialPoolSize" value="3"></property>        <property name="maxPoolSize" value="6"></property>    </bean>    <!-- 2) SessionFactory实例创建 -->    <!-- 所有的配置都由spring维护(项目中不需要hibernate.cfg.xml啦) -->    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">        <!-- a. 连接池 -->        <property name="dataSource" ref="dataSource"></property>        <!-- b. hibernate常用配置： 方言、显示sql、自动建表等 -->        <property name="hibernateProperties">            <props>                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>                <prop key="hibernate.show_sql">true</prop>                <prop key="hibernate.hbm2ddl.auto">update</prop>            </props>        </property>        <!-- c. 映射配置 -->        <property name="mappingLocations">            <list>                <value>classpath:zhongfucheng/entity/*.hbm.xml</value>            </list>        </property>    </bean>    <!-- 3) 事务配置 -->    <!-- # 事务管理器 -->    <bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">        <property name="sessionFactory" ref="sessionFactory"></property>    </bean>    <!-- # 事务增强 --><!--    <tx:advice id="txAdvice" transaction-manager="txManager">        <tx:attributes>            <tx:method name="*" read-only="false"/>        </tx:attributes>    </tx:advice>    &lt;!&ndash; # AOP配置 &ndash;&gt;    <aop:config>        <aop:pointcut expression="execution(* cn.itcast.service.*.*(..))" id="pt"/>        <aop:advisor advice-ref="txAdvice" pointcut-ref="pt"/>    </aop:config>-->    <!--4)开启注解扫描器-->    <context:component-scan base-package="zhongfucheng"/>    <!--5)开启注解处理事务-->    <tx:annotation-driven transaction-manager="txManager"/></beans>

编写entity

需求：获取用户信息的时，能够得到用户拥有的角色。

• Dept.java

package zhongfucheng.entity;/** * Created by ozc on 2017/5/15. */public class Dept {    private int id;    private String name;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

• User.java

package zhongfucheng.entity;/** * Created by ozc on 2017/5/15. */public class User {    private String id;    private String username;    private Dept dept;    public String getId() {        return id;    }    public void setId(String id) {        this.id = id;    }    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public Dept getDept() {        return dept;    }    public void setDept(Dept dept) {        this.dept = dept;    }}

entity的映射文件

User.hbm.xml

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="zhongfucheng.entity">    <class name="User" table="t_user">        <id name="id" column="user_id">            <generator class="native"></generator>        </id>        <property name="username" column="userName"></property>        <many-to-one name="dept" class="Dept" column="dept_id"/>    </class></hibernate-mapping>

Dept.hbm.xml

<?xml version="1.0" encoding="UTF-8" ?><!DOCTYPE hibernate-mapping PUBLIC     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"><hibernate-mapping package="zhongfucheng.entity">    <class name="Dept" table="t_dept">        <id name="id" column="deptId">            <generator class="native"></generator>        </id>        <property name="name" column="deptName"></property>    </class></hibernate-mapping>

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编写Dao

把Dao添加到容器上，并且得到sessionFactory对象

@Repositorypublic class UserDao {    @Autowired    private SessionFactory sessionFactory;    public User findbyId(int id) {        return (User) sessionFactory.getCurrentSession().get(User.class, id);    }}

编写Service

得到UserDao对象，把UserService添加到容器中

@Servicepublic class UserService {    @Autowired    private UserDao userDao;    public User findbyId(int id) {        return userDao.findbyId(id);    }}

编写Action

设置Action的实例为多例，得到userService对象，将查询结果存放到request域对象中

@Controller@Scope("prototype")public class UserAction extends ActionSupport {    @Autowired    private UserService userService;    @Override    public String execute() throws Exception {        //假设查询员工的主键为1        int user_id = 1;        User user = userService.findbyId(user_id);        //得到request对象，把数据存到request中        Map<String, Object> request = ActionContext.getContext().getContextMap();        request.put("user", user);        return SUCCESS;    }}

Struts2配置文件

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE struts PUBLIC        "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"        "http://struts.apache.org/dtds/struts-2.3.dtd"><struts>    <package name="aaa" extends="struts-default">        <action name="show" class="userAction" method="execute">            <result name="success">/show.jsp</result>        </action>    </package></struts>

JSP页面代码

<%@ page contentType="text/html;charset=UTF-8" language="java" %><html>  <head>    <title>$Title$</title>  </head>  <body>  员工的姓名：${user.username}  </body></html>

测试效果

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OpenSessionInView

我们在学习Hibernate的时候已经说过，Hibernate默认是开启懒加载的。当用到对象的时候才去获取数据…现在我在JSP页面上获取员工的部门是什么，出现了错误

为什么呢？Spring的事务控制是在Service层的，当Service层调用完之后，事务就会被提交。然而到了Action层的时候，事务已经关闭了。JSP就获取不到事务关闭后的数据了！

Spring也知道我们Hibernate的懒加载技术，可能使我们老是自己写拦截器去开启Session，直到view层关闭。于是Spring提供了OpenSessionInView供我们使用：在web.xml文件下配置就行了。

    <!-- 配置spring的OpenSessionInView模式 【目的：JSp页面访问懒加载数据】 -->    <!-- 注意：访问struts时候需要带上*.action后缀 -->    <filter>        <filter-name>OpenSessionInView</filter-name>        <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>    </filter>    <filter-mapping>        <filter-name>OpenSessionInView</filter-name>        <url-pattern>*.action</url-pattern>    </filter-mapping>

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