javaweb：ServletContext应用（一）——获取初始化参数

利用SerlvetContext读取初始化参数

首先我们要在web.xml增加一点初始化参数用于测试

    <context-param>
        <param-name>sctest</param-name>
        <param-value>this is a test message</param-value>
    </context-param>

 然后我们需要建立一个测试类 ServletDemo001

package com.jms.servlet;

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;

public class ServletDemo001 extends HttpServlet{

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        ServletContext context = this.getServletContext();//获取ServletContext对象
        String test = context.getInitParameter("sctest");//获取名为sctest的初始化参数
        resp.getWriter().print(test);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
    
}

我们需要再次修改web.xml为新的类注册servlet

    <!--注册Servlet-->
    <servlet>
        <servlet-name>demo001</servlet-name>
        <servlet-class>com.jms.servlet.ServletDemo001</servlet-class>
    </servlet>
    <!--Servlet的请求路径-->
    <servlet-mapping>
        <servlet-name>demo001</servlet-name>
        <url-pattern>/demo001</url-pattern>
    </servlet-mapping>

最后进行测试

 

 没有问题

 

（本文仅作个人学习记录用，如有纰漏，敬请指正）