import java.io.*;import java.util.*;import java.util.regex.*;import java.util.jar.*;/***Looks up information for given port**Copyright (C) 2002 Tom Salmon tom@slashtom.org**This program is free software; you can redistribute it and/ormodify it under the terms of the GNU General Public Licenseas published by the Free Software Foundation; version 2.This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free SoftwareFoundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.**@author Tom Salmon tom@slashtom.org*@version 0.3.1*/public class PortLookup{	protected String defsFile;	protected String [] portsList;	protected final String JAR_FILE_NAME = "jmap.jar";	/**	*Constructs port lookup object, to lookup service usually associated with	*a given port number	*@param String definitions file, similar in style to the one in 	* /etc/services	*@throws NullPointerException error getting to file	*/	public PortLookup(String defsFile) throws NullPointerException{		this.defsFile = defsFile;		String ports = new String();		String temp = new String();		try{			JarFile arch = new JarFile(this.JAR_FILE_NAME);			BufferedReader in = new BufferedReader(new InputStreamReader(								arch.getInputStream(arch.getEntry(defsFile))));			while(temp != null){				temp = in.readLine();				ports += temp + "\n";			}		}		catch(Exception e){			System.err.println(e.getMessage());		}		portsList = ports.split("\n"); //split line into array	}	/**	*Gets the service normally associated with the given port, if known	*@param int port to find service name for	*@param String protocol, such as tcp or udp	*@return String the service name, or Unknown	*/	public String getService(int port, String protocol){		for (int i=0; i<portsList.length; i++){			if (portsList[i].matches(".*\t" + port + "\\/" + protocol + ".*")){ 				if (portsList[i].indexOf("\t") > 0){					return portsList[i].substring(0,portsList[i].indexOf("\t"));				}			}		}		return "UNKNOWN";	}	/**	*Gets all port numbers that are associated with a service	*@returns int array the list of ports	*/	public int[] getActivePorts(){		Vector resultStrings = new Vector();		int start, stop;				for (int i=0; i<portsList.length; i++){			if (portsList[i].startsWith("#")){ //comment				continue;			}			start = portsList[i].indexOf("\t");			stop = portsList[i].indexOf("/tcp");			if (start < stop && start > 0){				resultStrings.add(portsList[i].substring(start+1, stop).trim());			}		}		int [] results = new int[resultStrings.size()];		for (int i=0; i<resultStrings.size(); i++){			results[i] = Integer.parseInt((String)resultStrings.get(i));		}		return results;	}	public static void main(String [] args){		if (args.length != 1){			System.err.println("USAGE: portLookup <port_number>");			System.exit(0);		}		PortLookup p;		try{			p = new PortLookup("ports.defs");			System.out.println( p.getService(Integer.parseInt(args[0]), "tcp"));		}		catch(Exception e){			System.err.println("Couldn't open port definitions file");			System.exit(-1);		}	}}