/* * This file is part of "The Java Telnet Application". * * This is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * "The Java Telnet Application" is distributed in the hope that it will be  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. *  * You should have received a copy of the GNU General Public License * along with this software; see the file COPYING.  If not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */package de.mud.jta.plugin;import de.mud.jta.Plugin;import de.mud.jta.FilterPlugin;import de.mud.jta.PluginBus;import de.mud.jta.PluginConfig;import de.mud.jta.event.ConfigurationListener;import de.mud.jta.event.OnlineStatusListener;import java.io.IOException;import java.util.Vector;/** * The script plugin takes a series of match and answer pairs to compare * the incoming data with the matches and if it succeeds writes the answers * back. It then moves on to the next match until all script elements have * matched.<P> * The script property Script.script should contain <B>|</B> separated strings * where each two represent a match and answer pair. A newline will be appended * to each answer!<P> * The script is very basic but is a very good example how to * write a plugin for <B>The Java<SUP>tm</SUP> Telnet Application</B>. * <P> * <B>Maintainer:</B> Matthias L. Jugel * * @version $Id: Script.java,v 2.4 2000/03/17 06:47:32 leo Exp $ * @author Matthias L. Jugel, Marcus Mei遪er */public class Script extends Plugin implements FilterPlugin {  /** debugging level */  private final static int debug = 0;  /** the script after parsing, saved for reinitialization */  private Vector savedScript;  /**   * Create a new scripting plugin.   */  public Script(PluginBus bus, final String id) {    super(bus, id);    bus.registerPluginListener(new OnlineStatusListener() {      public void online() {        setup(savedScript);      }      public void offline() {        // ignore disconnection      }    });    bus.registerPluginListener(new ConfigurationListener() {      public void setConfiguration(PluginConfig config) {        savedScript = new Vector();        String s = config.getProperty("Script", id, "script");        if(s != null) {	  // check if the script is stored in a file	  if(s.charAt(0) == '@') {	    Script.this.error("@file not implemented yet");	  }	  // parse the script and set up  	  if(debug > 0) Script.this.error(s);	  String pair[] = null;          int old = -1, idx = s.indexOf('|');          while(idx >= 0) {	    if(pair == null) {	      pair = new String[2];              pair[0] = s.substring(old + 1, idx);	      if(debug > 0) System.out.print("match("+pair[0]+") -> ");	    } else {              pair[1] = s.substring(old + 1, idx)+"\n";	      if(debug > 0) System.out.print(pair[1]);	      savedScript.addElement(pair);	      pair = null;	    }            old = idx;            idx = s.indexOf('|', old + 1);          }          if(pair != null) {	    pair[1] = s.substring(old + 1)+"\n";	    savedScript.addElement(pair);	    if(debug > 0) System.out.print(pair[1]);	  } else	    Script.this.error("unmatched pairs of script elements");	   // set up the script	  //  setup(savedScript);        }      }    });  }  /** holds the data source for input and output */  protected FilterPlugin source;  /**   * Set the filter source where we can read data from and where to   * write the script answer to.   * @param plugin the filter plugin we use as source   */  public void setFilterSource(FilterPlugin plugin) {    source = plugin;  }  /**   * Read an array of bytes from the back end and put it through the   * script parser to see if it matches. It will send the answer    * immediately to the filter source if a match occurs.   * @param b the array where to read the bytes in   * @return the amount of bytes actually read   */  public int read(byte[] b) throws IOException {    int n = source.read(b);    if(n > 0) match(b, n);    return n;  }  public void write(byte[] b) throws IOException {    source.write(b);  }  // =================================================================  // the actual scripting code follows:  // =================================================================  private int matchPos;		// current position in the match  private Vector script;	// the actual script  private byte[] match;		// the current bytes to look for  private boolean done = true;	// no script!  /**   * Setup the parser using the passed script. The script contains for   * every element a two-element array of String where element zero   * contains the match and element one the answer.   * @param script the script   */  private void setup(Vector script) {    // clone script to make sure we do not change the original    this.script = (Vector)script.clone();    if(debug > 0)       System.err.println("Script: script contains "+script.size()+" elements");    match = ((String[])this.script.firstElement())[0].getBytes();    reset();    done = false;  }  /**   * Try to match the byte array s against the most current script match.   * It will write the answer immediatly  if the script matches and   * will return instantly when all the script work is done.   * @param s the array of bytes to match against   * @param length the amount of bytes in the array   */  private void match(byte[] s, int length) throws IOException {    for(int i = 0; !done && i < length; i++) {      if(s[i] == match[matchPos]) {        // the whole thing matched so, return the match answer         // and reset to use the next match        if(++matchPos >= match.length)          write(found());      } else // if the current character did not match reset         reset();    }  }  /**   * This method is called when a script match was found and will   * setup the next match to be used and return the answer for the   * just found one.   * @return the answer to the found match   */  private byte[] found() {    if(debug > 0) System.err.println("Script: found '"+new String(match)+"'");    // we have matched the string, so remember the answer ...    byte[] answer = ((String[])script.firstElement())[1].getBytes();    // remove the matched element    script.removeElementAt(0);    // set the next match if applicable    if(!script.isEmpty()) {      match = ((String[])script.firstElement())[0].getBytes();      reset();    } else      done = true;    return answer;  }  /**   * Reset the match position counter.   */  private void reset() {    matchPos = 0;  }}