Java Proxy Server project

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

class aproxy extends Thread {

    Socket socket;
    aproxy(Socket s) {socket = s;}

    public static void main(String args[]) {
        try {

            ServerSocket ss = new ServerSocket(8080);
            while(true) {
                System.err.print("-Waiting for Clients \r\n");
                Socket s = ss.accept();
                System.err.print("-Client Accepted \r\n");
                System.err.print(" Number of Active Threads: "+activeCount()+"\r\n");
                Thread t = new aproxy(s);
                t.start();
            }
        } catch (IOException e) {}
    }

    public void run() {
        try {
            Scanner in = new Scanner(socket.getInputStream()); // CLIENT-->PROXY
            PrintWriter out = new PrintWriter(socket.getOutputStream(),true); // PROXY-->CLIENT
            if (isGET(in,out))
                readRequestHead(in,out);
            System.err.print("-Client Gone \r\n");
        } catch (Exception e) {}
    }

    public boolean isGET (Scanner in,PrintWriter out) { // Get the input from the client:
        String head = in.next(); //The word 'GET'.
        if ( !head.toUpperCase().equals("GET") ) {
            sendEResponse(out,1,null);
            return false;
            } else
                return true;
    }

    public void sendEResponse (PrintWriter out, int exceptionCase, String targetAddr) { // Send the errors and exceptions:
        try {
        switch (exceptionCase){

        case 1:
            //System.err.println("Not an HTTP 'GET' petition!");
            out.print("HTTP/1.1 501 Not Implemented\r\n");
            out.print("Content-Length: xxxx\r\n");
            out.print("Content-Type: xxxx\r\n");
            out.print("Connection: close\r\n");
            out.print("\r\n");
            out.print("<HTML>\n"+"<HEAD><TITLE>Error - Proxy Java</TITLE></HEAD>\n"+"<BODY bgColor=#FF9900><H1>Error HTTP 501</H1>\n"+"<H2> The method you're using is not valid for the HTTP protocol! </H2>\n"+"</BODY>\n"+"</HTML>\r\n\r\n");
            out.flush();
            socket.close();
            break;

        case 2:
            //System.err.println("Unknown host!");
            out.print("HTTP/1.1 302 Found\r\n"+"Location: http://www.google.com/search?q="+targetAddr+"\r\n"+"Connection: close\r\n\r\n");
            out.flush();
            socket.close();
            break;

        case 3:
            //System.err.println("Connection rejected!");
            out.print("HTTP/1.1 500 Internal Server Error\r\n"+"Content­Length: xxxx\r\n"+"Content­Type: text/html; charset=utf­8\r\n"+"Connection: close\r\n");
            out.print("\r\n");
            out.print("<HTML>\n"+"<HEAD><TITLE>Error - Proxy Java</TITLE></HEAD>\n"+"<BODY bgColor=#FF9900><H1>Error HTTP 500</H1>\n"+"<H2> The server has rejected the request! </H2>\n"+"</BODY>\n"+"<HTML>\r\n\r\n");
            out.flush();
            socket.close();
            break;
        }
        } catch (IOException e) { System.err.println("IO error!"); }
    }

    public void readRequestHead (Scanner in,PrintWriter out) { // Get part of the header as the target address to make the socket:
        String path = in.next(); //Full path inside the target host.
        String lineOne = ("GET "+path+" "+in.next()+"\r\n"); //The first line with the 'GET' + the path of the host and the http version.
        String wordHost = (in.next()+" "); //The word 'Host:' of the header and the space.
        String targetAddr = in.next(); //The target host itself.
        String lineTwoEnd = (targetAddr+in.nextLine()+"\r\n"); //The host + the end of the line.
        String lineTwo = (wordHost+lineTwoEnd);
        readNsendRequest(in,out,lineOne,lineTwo,targetAddr);
    }

    public void readNsendRequest (Scanner in,PrintWriter out,String lineOne,String lineTwo,String targetAddr) { // Get the remaining part of the header and send it to the target server:
        try {
        Socket tsocket = new Socket(targetAddr, 80); //Socket to the target server the client wants to access.
        PrintWriter tout = new PrintWriter(tsocket.getOutputStream(),true); // PROXY-->SERVER

        System.err.println("> Header from the client: \r\n");
        String line;
        System.err.print(lineOne+lineTwo);
        tout.print(lineOne+lineTwo);
        do {
            line = in.nextLine();

            if ( ( !line.equals("Connection: keep-alive") ) && ( !line.equals("Proxy-Connection: keep-alive") ) ) {
                System.err.print(line+"\r\n");
                tout.print(line+"\r\n");
            } else {
                System.err.print("Connection: close\r\n");
                tout.print("Connection: close\r\n");
            }
            } while( !line.equals("") );
        tout.flush();
        getNsendResponse(tsocket);
        } catch (UnknownHostException e) { sendEResponse(out,2,targetAddr); }
        catch (ConnectException e) { sendEResponse(out,3,null); }
        catch (IOException e) { System.err.println("IO error!"); }
    }

    public void getNsendResponse (Socket tsocket) { // Send the server output to the client:
        try {
        InputStream streamIn = tsocket.getInputStream(); // SERVER-->PROXY
        OutputStream streamOut = socket.getOutputStream(); // PROXY-->CLIENT

        System.err.println(">> Response from the server: \r\n");
        // Buffer:
        int i;
        byte[] b = new byte[1024];
        i = streamIn.read(b);
        while ( (i != 0) && (i != -1) ) { //Loop until the end of the stream.
            System.err.print("--Reading buffer\r\n");
            System.err.print("--Read "+i+" bytes\r\n");
            streamOut.write(b, 0, i);
            System.err.print("--Writing buffer\r\n");
            i = streamIn.read(b);
        }

        streamOut.flush();
        streamIn.close();
        streamOut.close();

        tsocket.close();
        socket.close();
        } catch (IOException e) { System.err.println("IO error!"); }
    }

}