Question

我需要检查特定网址是否已启动。网址的格式类似于

http://IP:port

当我使用java.net.URL课程时，我会获得java.net.SocketException或java.net.ConnectException。

当我ping这些IP时，我发现它们为什么java无法识别它们？

我写的代码是

URL url = new URL( urlString );
HttpURLConnection httpConn =  (HttpURLConnection)url.openConnection();
httpConn.setInstanceFollowRedirects( false );
httpConn.setRequestMethod( "HEAD" ); 
httpConn.connect();

端口号必须使用！如何使用java检查它们？

Answer 1

从这里工作得很好：

URL url = new URL( "http://google.com/" );
HttpURLConnection httpConn =  (HttpURLConnection)url.openConnection();
httpConn.setInstanceFollowRedirects( false );
httpConn.setRequestMethod( "HEAD" ); 
httpConn.connect();

System.out.println( "google.com : " + httpConn.getResponseCode());

或失败：

URL url = new URL( "http://google.com:666/" );
HttpURLConnection httpConn =  (HttpURLConnection)url.openConnection();
httpConn.setInstanceFollowRedirects( false );
httpConn.setRequestMethod( "HEAD" ); 
try{
    httpConn.connect();
     System.out.println( "google.com : " + httpConn.getResponseCode());
}catch(java.net.ConnectException e){
     System.out.println( "google.com:666 is down ");
}

Answer 2

可能是服务器已启动并正在运行（响应ping），但没有HTTP服务器正在侦听该端口。

Answer 3

也许还有其他事情发生但我发现这个页面让它完全符合您的要求： http://www.rgagnon.com/javadetails/java-0059.html

虽然它们在网址中没有端口号。

检查网址是否正常？

3 个答案: