Java 中如何检查 URL 是否有效

在Java中，我们经常需要检查URL是否有效。无论是在网站开发、爬虫还是其他网络相关的应用中，都需要对URL的有效性进行验证。本文将介绍如何在Java中检查URL是否有效，并提供相应的案例代码。

java
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
public class CheckURLValidity {
    public static void main(String[] args) {
        String urlString = "https://www.example.com";
        
        try {
            URL url = new URL(urlString);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            
            int responseCode = connection.getResponseCode();
            
            if (responseCode == 200) {
                System.out.println("URL is valid");
            } else {
                System.out.println("URL is invalid");
            }
        } catch (IOException e) {
            System.out.println("URL is invalid");
        }
    }
}

java
URL url = new URL(urlString);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
int responseCode = connection.getResponseCode();
if (responseCode == 200) {
    System.out.println("URL is valid");
} else {
    System.out.println("URL is invalid");
}

java
try {
    URL url = new URL(urlString);
    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
    connection.setRequestMethod("GET");
    int responseCode = connection.getResponseCode();
    if (responseCode == 200) {
        System.out.println("URL is valid");
    } else {
        System.out.println("URL is invalid");
    }
} catch (IOException e) {
    System.out.println("URL is invalid");
}