How to use SOCKS in Java?

I use 100% working socks and I can't connect through my application.

        SocketAddress proxyAddr = new InetSocketAddress("1.1.1.1", 12345);
        Proxy pr = new Proxy(Proxy.Type.SOCKS, proxyAddr);


    try
    {
        HttpURLConnection con = (HttpURLConnection) new URL(url).openConnection(pr);
        con.setConnectTimeout(proxyTimeout * 1000);
        con.setReadTimeout(proxyTimeout * 1000);
        con.connect();

        System.out.println(con.usingProxy());
    }
    catch(IOException ex)
    {
开发者_StackOverflow中文版        Logger.getLogger(Enter.class.getName()).log(Level.SEVERE, null, ex);
    }

So what am I doing wrong? If I'll use HTTP with some HTTP proxy all is working but not with SOCKS.

---

It's really easy. You just need to set the relevant System Properties and just get on with your regular HttpConnection.

System.getProperties().put( "proxySet", "true" );
System.getProperties().put( "socksProxyHost", "127.0.0.1" );
System.getProperties().put( "socksProxyPort", "1234" );

---

Inform the "socksProxyHost" and "socksProxyPort" VM arguments.

e.g.

java -DsocksProxyHost=127.0.0.1 -DsocksProxyPort=8080 org.example.Main

---

http://grepcode.com/file_/repository.grepcode.com/java/root/jdk/openjdk/8u40-b25/sun/net/www/http/HttpClient.java/?v=source

Deep down, HttpClient is used in HttpURLConnection.

if ((proxy != null) && (proxy.type() == Proxy.Type.HTTP)) {
   sun.net.www.URLConnection.setProxiedHost(host);
   privilegedOpenServer((InetSocketAddress) proxy.address());
   usingProxy = true;
   return;
} else {
   // make direct connection
   openServer(host, port);
   usingProxy = false;
   return;
}

On line 476, you can see that the only acceptable proxy is an HTTP proxy. It makes a direct connection otherwise.

Weirdly there's is no support for SOCKS proxy using HttpURLConnection. Even worse, the code doesn't even t using an unsupported proxy and just ignores the proxy!

Why there isn't any support for SOCKS proxies after at least 10 years of this class' existence cannot be explained.

---

Or this answer: https://stackoverflow.com/a/64649010/5352325

If you know which URIs need to go to proxy, you can also use the low layer ProxySelector: https://docs.oracle.com/javase/7/docs/technotes/guides/net/proxies.html where for each Socket connection that is made, you can decide what proxies are to be used.

It looks something like this:

public class MyProxySelector extends ProxySelector {
        ...

        public java.util.List<Proxy> select(URI uri) {
        ...
          if (uri is what I need) {
             return list of my Proxies
          }
        ...
        }
        ...
}
 

Then you make use of your selector:

public static void main(String[] args) {
        MyProxySelector ps = new MyProxySelector(ProxySelector.getDefault());
        ProxySelector.setDefault(ps);
        // rest of the application
}