1.需要引入额外的jar包:
2.spring的配置文件没什么区别。
3.如何创建IOC容器?
4.在WEB应用中其它组件如何来访问IOC容器呢?
可以将IOC容器放在ServletContext(即applicaiton域)的一个属性中。
5.实际上spring配置文件的名字和位置也是可以配置的。将其配置到当前web应用的初始化参数中较为合适。
实际操作:
新建一个动态的java web项目
需要注意的是不要直接按finish,要一直到最后将web.xml文件导入进来。
将相关的java包放入到WEB-INF的lib下。
相关目录如下:
Person.java
package com.gong.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);
}
}
SpringServletContextListener.java
package com.gong.spring.struts2.listeners;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
* Application Lifecycle Listener implementation class SpringServletContextListener
*
*/
@WebListener
public class SpringServletContextListener implements ServletContextListener {
/**
* Default constructor.
*/
public SpringServletContextListener() {
// TODO Auto-generated constructor stub
}
/**
* @see ServletContextListener#contextDestroyed(ServletContextEvent)
*/
public void contextDestroyed(ServletContextEvent arg0) {
// TODO Auto-generated method stub
}
/**
* @see ServletContextListener#contextInitialized(ServletContextEvent)
*/
public void contextInitialized(ServletContextEvent arg0) {
// TODO Auto-generated method stub
//1.获取spring配置文件的名称
ServletContext servletContext = arg0.getServletContext();
String config = servletContext.getInitParameter("contextConfigLocation");
//2..创建IOC容器
ApplicationContext ctx = new ClassPathXmlApplicationContext(config);
//3.将IOC容器放在ServletContext的一个属性中
servletContext.setAttribute("ApplicationContext", ctx);
}
}
TestServlet.java
package com.gong.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.gong.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();
}
}
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.gong.spring.struts2.beans.Person">
<property name="username" value="gong"></property>
</bean>
</beans>
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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
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>ssm</display-name>
<!-- 加载springIOC容器 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>applicationContext.xml</param-value>
</context-param>
<!-- 启动IOC容器的ServletContextListener -->
<listener>
<listener-class>com.gong.spring.struts2.listeners.SpringServletContextListener</listener-class>
</listener>
<servlet>
<description></description>
<display-name>TestServlet</display-name>
<servlet-name>TestServlet</servlet-name>
<servlet-class>com.gong.spring.struts2.servlets.TestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TestServlet</servlet-name>
<url-pattern>/TestServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
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>
启动tomcat服务器之后,访问http://localhost:8080/myspring5/index.jsp
点击:
在终端输出:
说明在WEB应用中配置和使用springIOC容器是成功的。