servlet Context

<?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">
  <display-name>servlet_demo03</display-name>
  
  <!-- 配置上下文参数 -->
  <context-param>
  		<param-name>version</param-name>
  		<param-value>Version 1.0</param-value>
  </context-param>
  
  <servlet>
  	<servlet-name>servletContext</servlet-name>
  	<servlet-class>servlet_demo03.Servlet_Context</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>servletContext</servlet-name>
  	<url-pattern>/context.do</url-pattern>
  </servlet-mapping>
  
  <servlet>
  	<servlet-name>servletContext02</servlet-name>
  	<servlet-class>servlet_demo03.Servlet_Context02</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>servletContext02</servlet-name>
  	<url-pattern>/context02.do</url-pattern>
  </servlet-mapping>
  
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

package servlet_demo03;

import java.io.IOException;
import java.io.PrintWriter;

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

public class Servlet_Context extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = -4997823504444105170L;

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

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		//获取上下文对象
		ServletContext sc=this.getServletContext();
		PrintWriter out=resp.getWriter();
		out.print(sc.getInitParameter("version"));
		
	}

}

package servlet_demo03;

import java.io.IOException;
import java.io.PrintWriter;

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

public class Servlet_Context02 extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 7562320935883704783L;

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

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		ServletContext sc=this.getServletContext();
		PrintWriter out=resp.getWriter();
		out.print(sc.getInitParameter("version"));
	}
	
}