Java – Exception in Connection time out for HttpURLConnection in Java programming

Ok, I have found the problem.

The HttpURLConnection did the OwnProxySelector.select() twice if the requested URL does not contain a port.

At first, HttpURLConnection invoked the select() with an URI, with the Scheme of "http" but no port. The select() checks whether the host address and port are euqal to intranetAddress or extranetAddress. This didn't match, because the port was not given. So the select return a Proxy for a direct connection.

At the second HttpURLConnection invoked the select() with an URI, with the Scheme of "socket" and port 80. So, because the select() checks host address and port, but not the scheme, it returned a HTTP proxy.

Now here is my corrected version of OwnProxySelector. It checks the scheme and sets the default port for HTTP or HTTPS if the port is not given by the URI. Also it asks the Java standard ProxySelector, if no HTTP or HTTPS scheme is given.

public class OwnProxySelector extends ProxySelector {
private ProxySelector defaultProxySelector;
private Proxy intranetProxy;
private Proxy extranetProxy;
private Proxy directConnection = Proxy.NO_PROXY;
private URI intranetAddress;
private URI extranetAddress;


public OwnProxySelector(ProxySelector defaultProxySelector){
    this.defaultProxySelector = defaultProxySelector;
}

/* (non-Javadoc)
 * @see java.net.ProxySelector#connectFailed(java.net.URI, java.net.SocketAddress, java.io.IOException)
 */
public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
    // Nothing to do
}

/* (non-Javadoc)
 * @see java.net.ProxySelector#select(java.net.URI)
 */
public List select(URI uri) {
    ArrayList<Proxy> result = new ArrayList<Proxy>();
    
    if(uri.getScheme().equalsIgnoreCase("http") || uri.getScheme().equalsIgnoreCase("https")){
        int uriPort = uri.getPort();
        
        // set default http and https ports if port is not given in URI
        if(uriPort<1){
            if(uri.getScheme().equalsIgnoreCase("http")){
                uriPort = 80;
            }
            else if(uri.getScheme().equalsIgnoreCase("https")){
                uriPort = 443;
            }
        }
        
        if(intranetAddress.getHost().equals(uri.getHost()) && intranetAddress.getPort()==uriPort){
            result.add(intranetProxy);
            System.out.println("Adding intranet Proxy!");
        }
        else if(extranetAddress.getHost().equals(uri.getHost()) && extranetAddress.getPort()==uriPort){
            result.add(extranetProxy);
            System.out.println("Adding extranet Proxy!");
        }
    }
    
    if(result.isEmpty()){
        List<Proxy> defaultResult = defaultProxySelector.select(uri);
        if(defaultResult!=null && !defaultResult.isEmpty()){
            result.addAll(defaultResult);
            System.out.println("Adding Proxis from default selector.");
        }
        else{
            result.add(directConnection);
            System.out.println("Adding direct connection, because requested URI does not match any Proxy");
        }
    }
    
    return result;
}

public void setIntranetProxy(String proxyAddress, int proxyPort){
    if(proxyAddress==null || proxyAddress.isEmpty()){
        intranetProxy = Proxy.NO_PROXY;
    }
    else{
        SocketAddress address = new InetSocketAddress(proxyAddress, proxyPort);
        intranetProxy = new Proxy(Proxy.Type.HTTP, address);
    }
}

public void setExtranetProxy(String proxyAddress, int proxyPort){
    if(proxyAddress==null || proxyAddress.isEmpty()){
        extranetProxy = Proxy.NO_PROXY;
    }
    else{
        SocketAddress address = new InetSocketAddress(proxyAddress, proxyPort);
        extranetProxy = new Proxy(Proxy.Type.HTTP, address);
    }
}

public void clearIntranetProxy(){
    intranetProxy = Proxy.NO_PROXY;
}

public void clearExtranetProxy(){
    extranetProxy = Proxy.NO_PROXY;
}

public void setIntranetAddress(String address) throws URISyntaxException{
    intranetAddress = new URI(address);
}

public void setExtranetAddress(String address) throws URISyntaxException{
    extranetAddress = new URI(address);
}

}

But it is curious to me, that the HttpURLConnection did a second invoke of select(), when it got a direct connection Proxy from the first invoke.

This worked for me. :)

URL url = new URL("http://userserve-ak.last.fm/serve/126/8636005.jpg");
Image image = ImageIO.read(url.openStream());
System.out.println(image);

I know I am late. Since, even I faced the same issue, thought of putting as it would help some one. :)