Program to check existence of a url hangs!!!

Question

Here is my code to check whether a url exists ...
import java.net.*;
import java.io.*;
import java.util.*;
public class urlExists
     urlExists()
     public int exists(String urlname) throws IOException
          URL url=null;
          try
            url=new URL(urlname);
          catch(Exception e)
            HttpURLConnection connexion = (HttpURLConnection)(url.openConnection());
            if(connexion.getResponseCode()==HttpURLConnection.HTTP_NOT_FOUND)
                    return(0);
            else return(1);
}I am using this class many a times but it keeps on hanging for some reason or another. Could anyone please explain me the reason?
Thanks in advance.
Regards
kbhatia

Answer 1

you will have to use a Socket:
public String getResponse(String url) throws Exception{
        int timeout   = 30000; // 30 second timeout
        String inputLine = null;
        Socket socket    = null;
        BufferedReader reader = null;
        Writer writer    = null;
        StringBuffer buf = new StringBuffer();
        try{
            URL server = new URL(url);
            int port = server.getPort();
            if (port < 0)
                port = 80;
            socket = new Socket(server.getHost(),port);
            writer = new OutputStreamWriter(socket.getOutputStream(), "US-ASCII");
            writer.write("GET " + server.toExternalForm() + " HTTP/1.0\r\n");
            writer.write("Host: " + server.getHost() + ':' + port + "\n\n");
            writer.flush();
            socket.setSoTimeout(timeout);
            reader = new BufferedReader(new InputStreamReader(socket.getInputStream(),"UTF-8"));
            String line = reader.readLine();
            if (line != null && line.startsWith("HTTP/")){
                int space = line.indexOf(' ');
                String status = line.substring(space + 1,space + 4);
                if (!status.equals("200")){
                    throw new Exception("HTML Error: + " status);
                while((line = reader.readLine()) != null)
                    buf.append(line).append("\n");
            else{
                throw new Exception("Bad protocol");
        catch (InterruptedIOException e) {
            throw new Exception("Read timeout expired");
        finally{
            // close the reader, writer, and socket here
        return buf.toString();      
}