Spring 教程06

Posted 2020-10-05 c0

spring-6
1.    Xml


<!-- \build\classes\applicationContext.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="person"
        class="com.atguigu.spring.struts2.beans.Person">
        <property name="username" value="atguigu"></property>
    </bean>
    
</beans>

<!-- \src\applicationContext.xml -->
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="person"
        class="com.atguigu.spring.struts2.beans.Person">
        <property name="username" value="atguigu"></property>
    </bean>
    
</beans>

<!-- \WebContent\WEB-INF\web.xml -->
<?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_2_5.xsd" id="WebApp_ID" version="2.5">
  <context-param>
    <param-name>configLocation</param-name>
    <param-value>applicationContext.xml</param-value>
  </context-param>
  <listener>
    <listener-class>com.atguigu.spring.struts2.listeners.SpringServletContextListener</listener-class>
  </listener>
  <servlet>
    <description></description>
    <display-name>TestServlet</display-name>
    <servlet-name>TestServlet</servlet-name>
    <servlet-class>com.atguigu.spring.struts2.servlets.TestServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>TestServlet</servlet-name>
    <url-pattern>/TestServlet</url-pattern>
  </servlet-mapping>
</web-app>

2.    Java


// \src\com\atguigu\spring\struts2\beans\Person.java
package com.atguigu.spring.struts2.beans;

public class Person {
    
    private String username;
    
    public void setUsername(String username) {
        this.username = username;
    }
    
    public void hello(){
        System.out.println("My name is " + username);
    }
    
}

// \src\com\atguigu\spring\struts2\listeners\SpringServletContextListener.java
package com.atguigu.spring.struts2.listeners;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * Application Lifecycle Listener implementation class SpringServletContextListener
 *
 */
public class SpringServletContextListener implements ServletContextListener {

    /**
     * Default constructor. 
     */
    public SpringServletContextListener() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see ServletContextListener#contextInitialized(ServletContextEvent)
     */
    public void contextInitialized(ServletContextEvent arg0) {
        //1. 获取 Spring 配置文件的名称. 
        ServletContext servletContext = arg0.getServletContext();
        String config = servletContext.getInitParameter("configLocation");
        
        //1. 创建 IOC 容器
        ApplicationContext ctx = new ClassPathXmlApplicationContext(config);
        
        //2. 把 IOC 容器放在 ServletContext 的一个属性中. 
        servletContext.setAttribute("ApplicationContext", ctx);
    }

    /**
     * @see ServletContextListener#contextDestroyed(ServletContextEvent)
     */
    public void contextDestroyed(ServletContextEvent arg0) {
        // TODO Auto-generated method stub
    }
    
}

// \src\com\atguigu\spring\struts2\servlets\TestServlet.java
package com.atguigu.spring.struts2.servlets;

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 com.atguigu.spring.struts2.beans.Person;

/**
 * Servlet implementation class TestServlet
 */
public class TestServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1. 从 application 域对象中得到 IOC 容器的引用
        ServletContext servletContext = getServletContext();
        ApplicationContext ctx = (ApplicationContext) servletContext.getAttribute("ApplicationContext");
        
        //2. 从 IOC 容器中得到需要的 bean
        Person person = ctx.getBean(Person.class);
        person.hello();
    }

}

3.    Jsp


<!-- \WebContent\index.jsp -->
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    
    <a href="TestServlet">TestServlet</a>
    
</body>
</html>