Spring4.04中实现bean的scope(范围)设置为session或者request

摘要: Spring4.04中实现bean的scope(范围)设置为session或者request

Sping中bean的scope的值可以是singleton、prototype、request、session、global session。默认情况下是singleton。

只有在web容器中才能使用request、session、global session。

下面我怎么实现使用session或request的方法，不足之处请指出。

首先在eclipse中建一个web工程，整体架构如下图所示：



Spring的配置文件Spring-config.xml中的内容如下所示，下面的userService1的scope的值为session：

<?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"
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">
<context:annotation-config/>

<bean id="userDao1" class="com.yun.project.dao.UserDao" scope="prototype">
</bean>

<bean id="userService1" class="com.yun.project.service.UserService" scope="session">

<property name="userDao" ref="userDao1"/>

</bean>
</beans>

新建一个名为UserServlet的Servlet，内容如下所示：

package com.yun.project.servlet;

import java.io.IOException;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.yun.project.service.UserService;
import com.yun.project.util.Out;//Out是我将System.out.println()给封装了
//即Out.println(String)等价于System.out.println(String)

public class UserServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doGet(req, resp);
doPost(req, resp);
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// TODO Auto-generated method stub
//super.doPost(req, resp);
Out.println("到doPost了");
UserService userService = (UserService) getBean("userService1");//取出Spring中的userService1
userService.sayHello();

Out.println("这是learnSpring1中的");
}

private Object getBean(String beanId){
ServletContext servletContext = this.getServletContext();
Out.println(servletContext==null?"是null":"不是null");
ApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(servletContext);
Object myDao = context.getBean(beanId);
return myDao;
}
}

接下来是web.xml中的配置，内容如下：

<?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" 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>LearnSpring1</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<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>
<listener>
<listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
</listener>

<servlet>
<servlet-name>user</servlet-name>
<servlet-class>com.yun.project.servlet.UserServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>user</servlet-name>
<url-pattern>/user</url-pattern>
</servlet-mapping>

</web-app>

注，我没有给出userService的sayHello()，不过这没有涉及到spring的配置了，随便你怎么写。

需要的jar，我在这就不给出了。

本人亲测，可以用的。有问题可以联系我，邮箱是dmj1161859184@126.com