How to use SOCKS in Java?

Question

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)
    {
        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.

What error message do you get? *How* does this code fail to work? Also, are you using a SOCKS4 or SOCKS5 proxy — Daniel Martin, Apr 18 '11 at 00:32
I tried to use both of SOCKS4 and SOCKS5. This is the error message: http://pastebin.com/xFB2qZQs But! Socks is 100% woking (socks5 here is). — Clark, Apr 18 '11 at 13:03
Where i can get SOCKS5 library for android?? i want to use it also.. — Noman, May 30 '13 at 10:19

score 26 · Answer 1 · answered Aug 25 '12 at 14:42

26

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" );

answered Aug 25 '12 at 14:42

2hamed

8,719
13
69
112

1

These are correct but what to do in case I need to use multi threads and I need to have many Proxies per time ? For example I found socks proxy which works fine in IE as SOCKS (and does not wotk as HTTP and other protocols) but when I use it in Java this does not work for v4 and for 5 ! That seems like hug suck in Java – Andrew Niken Nov 23 '16 at 02:29
It's worth to mention that Java will ignore the SOCKS5 settings unless proxyset is set. This is not necessary for using an HTTP proxy. – Raúl Salinas-Monteagudo May 06 '19 at 13:40

score 7 · Answer 2 · answered Nov 30 '17 at 21:59

7

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

e.g.

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

answered Nov 30 '17 at 21:59

Marcelo C.

3,822
2
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11

score 2 · Answer 3 · edited Feb 17 '18 at 22:43

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.

score 1 · Answer 4 · answered Nov 02 '20 at 16:12

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
}

How to use SOCKS in Java?

4 Answers4