如何访问 url 并从 java servlet 获取其响应？

Question

我是 servlet 编程新手，我的任务是编写一个 srvlet 程序，该程序将访问 url 并检索其内容。请帮忙

Answer 1

你需要做这样的事情

import java.io.*;
import java.net.URL;
import java.net.URLConnection;

import javax.servlet.http.*;
import javax.servlet.*;


public class URLServlet extends HttpServlet {
    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {

        URL urldemo = new URL("http://www.demo.com/");
        URLConnection yc = urldemo.openConnection();
        BufferedReader in = new BufferedReader(new InputStreamReader(
                yc.getInputStream()));
        String inputLine;
        while ((inputLine = in.readLine()) != null)
            System.out.println(inputLine);
        in.close();

    }
}

纯java程序

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

public class URLServlet {

    public static void main(String s[]) {
        try {
        URL urldemo = new URL("http://www.google.com/");
        URLConnection yc = urldemo.openConnection();
        BufferedReader in = new BufferedReader(new InputStreamReader(
                yc.getInputStream()));
        String inputLine;
        while ((inputLine = in.readLine()) != null)
            System.out.println(inputLine);
        in.close();
        }catch(Exception e) {
            System.out.println(e);
        }
    }
}