Serverlet读取文件

1.在resources文件夹下新建一个db.properties文件，写入；

username=root
password=123456

2.java文件夹下建一个文件Demo05

package com.yin;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class Demo05 extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        InputStream is=this.getServletContext().getResourceAsStream("/WEB-INF/classes/db.properties");
        Properties prop = new Properties();
        prop.load(is);
        String user = prop.getProperty("username");
        String pwd = prop.getProperty("password");
        resp.getWriter().print(user + ":" + pwd);
    }

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

　　3.web.xml配置访问路径

    <servlet>
        <servlet-name>sd5</servlet-name>
        <servlet-class>com.yin.Demo05</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>sd5</servlet-name>
        <url-pattern>/sd5</url-pattern>
    </servlet-mapping>

　　4.运行TOMCAT,跳出页面后，地址加上/sd5,如下图；