Java

SocketChannel sch = SocketChannel.open();
Selector sel = Selector.open();
try {
    sch.configureBlocking(false);
    sch.connect(new InetSocketAddress("0", 80));
    sch.register(sel,SelectionKey.OP_CONNECT);
    sel.select();
    Iterator<SelectionKey> it = sel.selectedKeys().iterator();
    while (it.hasNext()) {
        SelectionKey sk = it.next();
        it.remove();
        if (sk.isConnectable()) {
            System.out.println("Connectable.");
            System.out.println(sch.finishConnect());
            System.out.println(sch.socket().isConnected());
            System.out.println(sch.socket().getInetAddress());
        }
    }
} finally {
    sch.close();
    sel.close();
}

Connectable.
true
true
/0.0.0.0

Socket s = new Socket();
s.connect(new InetSocketAddress("0", 80));

Socket s = new Socket("1",1);

Exception in thread "main" java.net.SocketException: Network is unreachable: connect
...

String test = "this is one test string to show you";