Spring实战之Bean的作用域request用法分析

Z时代
2024-01-10
分类：综合

本文实例讲述了Spring实战之Bean的作用域request用法。分享给大家供大家参考，具体如下：

一配置

1 applicationContext.xml


<?xml version="1.0" encoding="GBK"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns="http://www.springframework.org/schema/beans"
  xsi:schemaLocation="http://www.springframework.org/schema/beans
  http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
  <!-- 指定使用request作用域 -->
  <bean id="p" class="org.crazyit.app.service.Person"
    scope="request"/>
</beans>

2 web.xml


<?xml version="1.0" encoding="GBK"?>
<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">
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  <listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
  </listener>
</web-app>

二 Bean


package org.crazyit.app.service;
public class Person
{
  private int age;
}

三视图


<%@ page contentType="text/html; charset=GBK" language="java" errorPage="" %>
<%@ page import="org.springframework.web.context.*" %>
<%@ page import="org.springframework.web.context.support.*" %>
<%@ page import="org.crazyit.app.service.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <title>Spring Bean的作用域</title>
</head>
<body>
<%
// 获取Web应用初始化的Spring容器
WebApplicationContext ctx =
  WebApplicationContextUtils.getWebApplicationContext(application);
// 两次获取容器中id为p的Bean
Person p1 = (Person)ctx.getBean("p");
Person p2 = (Person)ctx.getBean("p");
out.println((p1 == p2) + "<br/>");
out.println(p1);
%>
</body>
</html>