Stuff

package edu.ncsu.ftp;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintStream;import java.net.BindException;import java.net.ServerSocket;import java.net.Socket;import java.net.SocketException;import java.util.HashMap;public class Ident    extends Thread{  private volatile static boolean running = false;  private volatile static boolean enabled = false;  private static String userid;  private static int expectedConns;  private static ServerSocket ss;  private static HashMap requestMap = null;  private static Ident ident = null;  private Ident(String id) throws Exception  {    if (running)      throw new Exception("Already running");    setUserID(id);    expectedConns = 0;  }  private synchronized void doNotify()  {    notifyAll();  }  private synchronized void doWait()  {    try    {      wait();    }    catch (InterruptedException e)    {    }  }  public static Ident getInstance()  {    return Ident.getInstance(Ident.getUserId());  }  public static Ident getInstance(String user_id)  {    if (requestMap == null)      requestMap = new HashMap();    if (ident == null)      try      {        running = false; // should never matter        ident = new Ident(user_id);      }      catch (Exception e)      {        e.printStackTrace(); // Should never get here..      }    return ident;  }  public static Ident startServer(String userid) throws Exception  {    //Ident.userid = userid;      Ident.setUserID(userid);    return Ident.startServer();  }  public static Ident startServer() throws Exception  {    if (userid == null)      throw new Exception(                          "IDENT service could not start (cannot start when user_id is empty)");    if (ident == null)      ident = Ident.getInstance();    if (running == true)      throw new Exception("IDENT service is already runnning");    if (enabled == false)      throw new Exception("IDENT service could not start (disabled)");    ident.start();    Thread.yield();    return ident;  }  public static void setUserID(String userid)  {    Ident.userid = userid;    Ident.enable();  }  public static String getUserId()  {    return userid;  }  public static void expectRequest()  {    if (!enabled)      return;    expectedConns++;    Ident.getInstance().doNotify();  }  /**   * @param ipAddress   * @param customId   */  public static void expectRequest(String ipAddress, String customId)  {    if (!enabled)      return;    requestMap.put(ipAddress, customId);    Ident.expectRequest();  }  public static void doneRequest()  {    if (expectedConns > 0)      expectedConns--;    if (ss != null && expectedConns <= 0)      try      {        ss.close();      }      catch (IOException e)      {      }  }  public static void enable()  {    enabled = true;  }  public static boolean isEnabled()  {    return enabled;  }  public static void disable()  {    enabled = false;    expectedConns = 0;    Ident.doneRequest();    if (requestMap == null)      return;    requestMap.clear();    requestMap = null;    if (!ss.isClosed())      try      {        ss.close();      }      catch (Exception e)      {        e.printStackTrace();      }  }  public static boolean isRunning()  {    return running;  }  public static void stopServer()  {    Ident.disable();    Ident.getInstance().doNotify();    try    {      ident.join();    }    catch (InterruptedException e)    {      System.err.println(e.toString());      e.printStackTrace();    }    finally    {      ident = null;    }  }  public void run()  {    // 1 at a time, please    if (running == true)      return;    running = true;    while (running)    {      try      {        while (expectedConns <= 0)        {          /*           * try { Thread.sleep(500); } catch (InterruptedException e) { }           */          Ident.getInstance().doWait();          continue;        }        try        {          ss = new ServerSocket(113);        }        catch (BindException e)        {          System.err                    .println("IDENT service unable to listen on port 113 (port already in use)");          expectedConns = 0;          continue;        }        catch (Exception e)        {          e.printStackTrace();          expectedConns = 0;          System.out                    .println("IDENT service unable to listen on port 113 (unknown error)");          continue;        }        // ss.setSoTimeout(30 * 1000);        while (expectedConns > 0)        {          IdentConn ic = new IdentConn(ss.accept());          ic.start();          Thread.yield();        }        ss.close();      }      catch (IOException e)      {        // e.printStackTrace();      }      ss = null;    }    running = false;  }  class IdentConn      extends Thread  {    private Socket sock;    public IdentConn(Socket s) throws SocketException    {      sock = s;      sock.setSoTimeout(30 * 1000);    }    public void run()    {      try      {        System.out.println("IDENT: Received IDENT request from "                           + sock.getInetAddress().getHostAddress());        BufferedReader in = new BufferedReader(                                               new InputStreamReader(                                                                     sock                                                                         .getInputStream()));        PrintStream out = new PrintStream(sock.getOutputStream());        Object o = requestMap.get(sock.getInetAddress().getHostAddress());        String tmp_id = o == null ? userid : o.toString();        String line = in.readLine();        if (line != null)        {          out.print(line + " : USERID : UNIX : " + tmp_id + "\r\n");          System.out.println(line + " : USERID : UNIX : " + tmp_id);        }        in.close();        out.close();        sock.close();      }      catch (SocketException e)      {        // boomshakalaka don't care      }      catch (IOException e)      {        e.printStackTrace();      }    }  }}