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  • context-param和init-param区别

    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.wes.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("下面的两个参数param1是在servlet中存放的");
             System.out.println(this.getInitParameter("param1"));
             System.out.println("下面的参数是存放在servletcontext中的");
            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")取得.
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  • 原文地址:https://www.cnblogs.com/xubc/p/3841002.html
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