Something

import java.io.*;
import java.net.*;
import java.util.LinkedList;

public class ProxyTester {
    public static void main(String[] args) throws IOException {
    	try {
    		outputList(tryProxies(getList(args[0])), args[1]);
    		
    	} catch(IOException e) {
    		System.out.print("IOException: "+e.toString());
    	}
    } 
    
    private static LinkedList<String> getList(String inputFilename) throws IOException {
    	LinkedList<String> list = new LinkedList<String>();
    	
    	BufferedReader stdIn = new BufferedReader(new FileReader(inputFilename));
    	String inputProxies;

    	while ((inputProxies = stdIn.readLine()) != null) {
    		list.add(inputProxies);
    	}
    	stdIn.close();
    	return list;
    }
    
    private static LinkedList<String> tryProxies(LinkedList<String> inputProxies) throws IOException {
    	LinkedList<String> workingProxies = new LinkedList<String>();
    	
    	for(String currentProxy : inputProxies) {
    		String tmp[] = currentProxy.split(":");
    		if(connect(tmp[0], Integer.parseInt(tmp[1]))) {
    			workingProxies.add(currentProxy);
    		}
    	}
    	
    	return workingProxies;
    }
    
    private static void outputList(LinkedList<String> workingProxies, String outputFilename) throws IOException {
    	BufferedWriter out = new BufferedWriter(new FileWriter(outputFilename));
    	
    	for(String currentProxy : workingProxies) {
    		out.write(currentProxy+"\n");
    	}
    	out.close();
    }
    
    private static boolean connect(String proxy, int port) throws IOException {
    	Socket proxySocket = new Socket(proxy, port);
        PrintWriter out = new PrintWriter(proxySocket.getOutputStream(), true);
        BufferedReader in = new BufferedReader(new InputStreamReader(
                                    proxySocket.getInputStream()));
        
        out.println("GET http://u1.swirve.com/");
        
        while(in != null) {
        	if(in.equals("HTTP/1.1 OK")) {
        		out.close();
                in.close();
                proxySocket.close();
        		
        		return true;
        	}
        }
        
        out.close();
        in.close();
        proxySocket.close();
    	
    	return false;
    }
}