didnotmatch.java

java实现正则表达式的代码

/*
 * $Id: didNotMatch.java,v 1.7 2003/11/07 20:16:23 dfs Exp $
 *
 * ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
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 */


package examples;

import org.apache.oro.text.regex.*;
import org.apache.oro.text.perl.*;

/**
 * This is a trivial example program demonstrating the preMatch()
 * and postMatch() methods of Perl5Util.
 *
 * @version @version@
 */
public final class didNotMatch {

  /**
   * This program takes a Perl5 pattern and an input string as arguments.
   * It prints the parts of the input surrounding the first occurrence
   * of the pattern in the input.
   */
  public static final void main(String args[]) {
    String pattern, input;
    Perl5Util perl;

    if(args.length < 2) {
      System.err.println("Usage: didNotMatch pattern input");
      System.exit(1);
    }

    pattern = args[0];
    input   = args[1];
    perl    = new Perl5Util();

    // Use a try block because we have no idea if the user will enter a valid
    // pattern.
    try {
      if(perl.match(pattern, input)) {
	System.out.println("Pre : " + perl.preMatch());
	System.out.println("Post: " + perl.postMatch());
      } else
	System.err.println("There was no match.");
    } catch(MalformedPerl5PatternException e) {
      System.err.println("You entered an invalid pattern.");
      System.err.println("Error: " + e.getMessage());
      System.exit(1);
    }

  }

}