[Jcommander-commit] plugins/org.jcommander.ui.app/src/org/jcommander/ui/app/singleton ApplicationEntryPoint.java,NONE,1.1 SingletonAppLauncher.java,NONE,1.1

[Robert E. <sky...@us...>]

Update of /cvsroot/jcommander/plugins/org.jcommander.ui.app/src/org/jcommander/ui/app/singleton
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv28827/src/org/jcommander/ui/app/singleton

Added Files:
	ApplicationEntryPoint.java SingletonAppLauncher.java 
Log Message:
Moved singleton instance related classes to separate package

--- NEW FILE: ApplicationEntryPoint.java ---
package org.jcommander.ui.app.singleton;

/**
 * <p></p>
 * @author Mike Grigorov
 * @version 1.0
 * Created on 2006-3-10
 */

public interface ApplicationEntryPoint {
	public String getIdentification();
	public void startup(String[] params);
}

--- NEW FILE: SingletonAppLauncher.java ---
package org.jcommander.ui.app.singleton;

import java.io.*;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;


/**
 * <p></p>
 * @author Mike Grigorov
 * @version 1.0
 * Created on 26.04.2006
 */

public class SingletonAppLauncher {
	private final ApplicationEntryPoint entryPoint; 
	private final int fromPort;
	private final int toPort;
	
	public SingletonAppLauncher(ApplicationEntryPoint entryPoint, int fromPort, int toPort){
		if(null == entryPoint){
			throw new NullPointerException("entryPoint");
		}
		if(fromPort < 0){
			throw new IllegalArgumentException("fromPort:" + fromPort);
		}
		if(toPort < 0){
			throw new IllegalArgumentException("toPort:" + toPort);
		}
		if(fromPort > toPort){
			throw new IllegalArgumentException(fromPort + ">" + toPort);
		}
		this.entryPoint = entryPoint;
		this.fromPort = fromPort;
		this.toPort = toPort;		
	}
	
	public boolean startingFirstInstance(String[] params){
		ServerSocket server = null;
		Socket sameApplication = null;
		for(int i = fromPort; i <= toPort; i++){
			ServerSocket loopSocket = tryToOccupy(i);
			if(null != loopSocket){
				if(null == server){
					server = loopSocket;
				}
				else{
					try{ 
						loopSocket.close();
					}catch(Exception ex){}
				}
			}
			else{
				Socket same = contactSameApplication(i);
				if(null != same){
					sameApplication = same;
					break;
				}
			}
		}
		try{
			if ((null != sameApplication) && (startSameApp(sameApplication, params))) {
				return false;
			} else {
				final ServerSocket serverSocket = server;
				new Thread(new Runnable(){
					public void run(){
						new HandshakeServer(serverSocket, entryPoint);
					}
				}, "Handshake server").start();
				entryPoint.startup(params);
				return true;
			}
		}
		finally{
			if(null != sameApplication){
				try {
					sameApplication.close();
				} catch (Exception e) {}
			}
		}
	}
	
	private boolean startSameApp(Socket sameApplication, String[] parameters){
		try{
			StringBuffer params = new StringBuffer();
			if(null != parameters){
				for(int i = 0; i < parameters.length; i++){
					if(null == parameters[i]){
						continue;
					}
					if(params.length() > 0){
						params.append(',');
					}
					params.append(parameters[i]);
				}
			}
			PrintWriter writer = new PrintWriter(sameApplication.getOutputStream());
			BufferedReader reader = new BufferedReader(new InputStreamReader(sameApplication.getInputStream()));
			writer.println(Requests.STARTUP_REQUEST + params.toString());
			writer.flush();
			reader.readLine();
			writer.println(Requests.DISCONNECT_REQUEST);
			writer.flush();
			return true;
		}
		catch(IOException ex){
			return false;
		}
	}
	
	private ServerSocket tryToOccupy(int port){
		try {
			return new ServerSocket(port);
		} catch (IOException e) {
			return null;
		} catch(Throwable t){
			t.printStackTrace();
			return null;
		}
	}
	
	private Socket contactSameApplication(int port){
		Socket client = null;
		boolean close = true;
		try {
			client = new Socket(InetAddress.getLocalHost(), port);
			client.setSoTimeout(250);			
			PrintWriter writer = new PrintWriter(client.getOutputStream());
			BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
			writer.println(Requests.RETRIEVE_ID_REQUEST);
			writer.flush();
			String line = reader.readLine();
			if(entryPoint.getIdentification().equals(line)){
				close = false;
				return client;
			}
			return null;
		} catch (IOException e) {
			System.err.println("Error communicating:" + e);
			return null;
		} catch (Throwable t){
			t.printStackTrace();
			return null;
		} finally{
			if(close && (null != client)){
				try {
					client.close();
				} catch (Exception e) {}
			}
		}
	}
	
	private static class HandshakeServer {
		private final ServerSocket socket;
		private final ApplicationEntryPoint entryPoint;
		
		public HandshakeServer(ServerSocket socket, ApplicationEntryPoint entryPoint){
			if(null == socket){
				throw new NullPointerException("socket");
			}		
			if(null == entryPoint){
				throw new NullPointerException("entryPoint");
			}		
			this.socket = socket;		
			this.entryPoint = entryPoint;
			while(true){
				try{
					Socket _client = socket.accept();
					new Thread(new ClientHandler(_client)).start();
				}
				catch(Throwable t){
					t.printStackTrace();
				}
			}
		}
		
		private class ClientHandler implements Runnable{
			private final Socket socket;
			public ClientHandler(Socket socket){
				if(null == socket){
					throw new NullPointerException("socket");
				}
				this.socket = socket;
			}
			
			public void run(){
				try{
					BufferedReader _reader = new BufferedReader(new InputStreamReader(
							socket.getInputStream()));
					PrintWriter _writer = new PrintWriter(socket.getOutputStream());
					String _line;
					while((_line = _reader.readLine()) != null){
						String _s = handleLine(_line);
						if(null != _s){
							_writer.println(_s);
							_writer.flush();
						}
						else{
							socket.close();
							break;
						}
					}
				}
				catch(IOException ex){
					ex.printStackTrace();
					System.out.println(ex);
				}
			}
			
			private String handleLine(String line){
				if(Requests.RETRIEVE_ID_REQUEST.equalsIgnoreCase(line)){
					return entryPoint.getIdentification();
				}
				if(Requests.DISCONNECT_REQUEST.equalsIgnoreCase(line)){
					return null;
				}
				if(line.startsWith(Requests.STARTUP_REQUEST)){
					String params = null;
					if(line.length() > Requests.STARTUP_REQUEST.length()){
						params = line.substring(Requests.STARTUP_REQUEST.length());
					}
					startup(params);
					return "OK";
				}
				return "UNKNOWN:" + line;
			}
			
			private void startup(String line){
				String[] params = null;
				if(null != line){
					params = line.split(",");
				}
				final String[] p = params;
				new Thread(new Runnable(){
					public void run(){
						entryPoint.startup(p);
					}
				}, "STARTUP").start();
			}
		}	
	}	
	
	private static class Requests{
		public static final String STARTUP_REQUEST = "STARTUP_";
		public static final String DISCONNECT_REQUEST = "HANDSHAKE_DISCONNECT";
		public static final String RETRIEVE_ID_REQUEST = "WHO_ARE_YOU";
		
		private Requests(){}
	}
}