web.xml中在Servlet中获取context-param和init-param内的参数

web.xml里面可以定义两种参数：
1.application范围内的参数，存放在servletcontext中，在web.xml中配置如下： 

 

<context-param>

           <param-name>context/param</param-name>

           <param-value>avalible during application</param-value>

  </context-param>

2.servlet范围内的参数，只能在servlet的init()方法中取得，在web.xml中配置如下：

 

 

<servlet>

    <servlet-name>MainServlet</servlet-name>

    <servlet-class>com.wes.controller.MainServlet</servlet-class>

    <init-param>

       <param-name>param1</param-name>

       <param-value>avalible in servlet init()</param-value>

    </init-param>

    <load-on-startup>0</load-on-startup>

</servlet>

在servlet中可以通过代码分别取用： 

 

package com.qisentech.controller;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

public class MainServlet extends HttpServlet {

    public MainServlet() {

        super();

      }

    public void init() throws ServletException {

          System.out.println(this.getInitParameter("param1"));

          System.out.println(getServletContext().getInitParameter("context/param"));

       }

}

 

第一种参数在servlet里面可以通过getServletContext().getInitParameter("context/param")得到
第二种参数只能在servlet的init()方法中通过this.getInitParameter("param1")取