问题描述

Servlet类加载文件读取资源

type Exception report

message

description The server encountered an internal error that prevented it from fulfilling this request.

exception

java.lang.NullPointerException
com.itheima.Service.methdo2(Service.java:10)
com.itheima.Demo8Servlet.doGet(Demo8Servlet.java:21)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.36 logs.

源码：package com.itheima;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Properties;
public class Service {
public void methdo2() throws FileNotFoundException,IOException{
Properties prop = new Properties();
prop.load(new FileReader(Service.class.getClassLoader().getResource("config.properties").getPath()));
System.out.println(prop.getProperty("username"));
System.out.println(prop.getProperty("password"));

}

}

package com.itheima;

import java.io.IOException;

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

public class Demo8Servlet extends HttpServlet {

/**
 *
 */
private static final long serialVersionUID = 1L;

public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    Service service = new Service();
    service.methdo2();
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    doGet(request, response);
}

}

解决方案

看看到吗
com.itheima.Service.methdo2(Service.java:10) 这第10行是什么，打断点看一下。

解决方案二：

prop.load(new FileReader(Service.class.getClassLoader().getResource("config.properties").getPath()));//”config.properties“路径问题