Method 1

UseJava.netThe URL class below implements that the URL is a reference to a uniform resource identifier, a URL instance represents a reference to a url, and then the openStream() method in the URL is used.

java code:
[java] view plain copy

import java.io.InputStream;  
import java.net.URL;  

public class URLTest {  
    public static void testUrl(String webUrl) {  
        URL url;  
        try {  
            url = new URL(webUrl);  
            InputStream inputStream = url.openStream();  
            System.out.println("Connection available!");  
        } catch (Exception e) {  
            e.printStackTrace();  
            System.out.println("Connection not available!");  
            url = null;   
        }  
    }  

    public static void main(String[] args) {  
        URLTest.testUrl("https://www.baidu.com");  
    }  
}  

Method 2

UseJava.netThe URL and HttpURLConnection classes below are implemented.It uses the getResponseCode() method in the HttpURLConnection, usually an instance of the HttpURLConnection can generate a request, and it has a method getResponseCode() to get the response status of the request, which returns an int of 200 and 404, respectively, and -1 if no code can be identified from the response.

Java code:

[java] view plain copy

import java.io.InputStream;  
import java.net.HttpURLConnection;  
import java.net.URL;  

public class URLTest {  
    public static boolean testUrl(String webUrl) {  
        try {  
            // Sets whether this class should automatically perform HTTP redirection (response code is 3xx for requests).  
            HttpURLConnection.setFollowRedirects(false);  
            // Connection to remote object referenced by URL  
            HttpURLConnection conn = (HttpURLConnection) new URL(webUrl).openConnection();  
            // Set the method of URL request, GET POST HEAD OPTIONS PUT DELETE TRACE  
            // One of the above methods is legal, depending on the limitations of the agreement.  
            conn.setRequestMethod("HEAD");  
            // Get status code from HTTP response message  
            return (conn.getResponseCode() == HttpURLConnection.HTTP_OK);  
        } catch (Exception e) {  
            e.printStackTrace();  
            return false;  
        }  
    }  

    public static void main(String[] args) {  
        URLTest.testUrl("https://www.baidu.com");  
    }  
}