如何快速测试 URL 是否存在并在 java 中有内容？

Question

我正在测试是否存在数百个 URL，而我目前的方式需要太多时间。这是我到目前为止发现的：public static boolean checkURL(URL u){HttpURLConnection connection = null;try{  connection = (HttpURLConnection) u.openConnection();  connection.setRequestMethod("HEAD");  int code = connection.getResponseCode();  System.out.println("" + code);  // You can determine on HTTP return code received. 200 is success.  if (code == 200)  {    return true;  }  else  {    return false;  }}catch (MalformedURLException e){  // TODO Auto-generated catch block  // e.printStackTrace();  System.out.println("error");}catch (IOException e){  System.out.println("error2");  // TODO Auto-generated catch block  // e.printStackTrace();}finally{  if (connection != null)  {    connection.disconnect();}}return false;}虽然这确实成功地找到了一个 URL 是否存在并且有内容，但它会在很长一段时间内完成，程序通常需要超过五分钟才能执行。有谁知道更有效的测试方法？注意：重要的是要测试不仅url返回200，而且网站没有超时。

Answer 1

您的代码看起来不错，它应该是检查 url 的最简单方法。您可能希望在 HttpURLConnection中添加超时。

示例代码供参考。

enter code here

import java.net.HttpURLConnection;

import java.net.URL;

public class UrlChecker {

public static void main(String[] args) {

System.out.println(URLExists("http://slowwly.robertomurray.co.uk/delay/

3000/url/http://www.google.co.uk"));

}

public static boolean URLExists(String targetUrl) {

    HttpURLConnection urlConnection;

    try {

        urlConnection = (HttpURLConnection) new 

        URL(targetUrl).openConnection();

        urlConnection.setRequestMethod("HEAD");

        // Set timeouts 2000 in milliseconds and throw exception

        urlConnection.setConnectTimeout(2000);

        urlConnection.setReadTimeout(2000);

       /* Set timeouts 4000 in milliseconds and it should work as the url 

        should return back in 3 seconds.

        httpUrlConn.setConnectTimeout(4000);

        httpUrlConn.setReadTimeout(4000);

        */

        System.out.println("Response Code =>"+ 

        urlConnection.getResponseCode());

        System.out.println("Response Msg =>"+ 

        urlConnection.getResponseMessage());

        return (urlConnection.getResponseCode() == 

        HttpURLConnection.HTTP_OK);

    } catch (Exception e) {

        System.out.println("Exception => " + e.getMessage());

        return false;

    }

}

}