semicolon.java

java实现正则表达式的代码

/*
 * $Id: semicolon.java,v 1.8 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.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    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.
 *
 * 4. The names "Apache" and "Apache Software Foundation", "Jakarta-Oro" 
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache" 
 *    or "Jakarta-Oro", nor may "Apache" or "Jakarta-Oro" appear in their 
 *    name, without prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * 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
 * <http://www.apache.org/>.
 */


package examples;

import java.io.*;

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

/**
 * This is a simple example program showing how to use the MatchActionProcessor
 * class.  It reads the provided semi-colon delimited file semicolon.txt and
 * outputs only the second column to standard output.
 *
 * @version @version@
 */
public final class semicolon {

  public static final void main(String[] args) {
    MatchActionProcessor processor = new MatchActionProcessor();

    try {
      processor.setFieldSeparator(";");
      // Using a null pattern means to perform the action for every line.
      processor.addAction(null, new MatchAction() {
	public void processMatch(MatchActionInfo info) {
	  // We assume the second column exists
	  info.output.println(info.fields.get(1));
	}
      });
    } catch(MalformedPatternException e) {
      e.printStackTrace();
      System.exit(1);
    }

    try {
      processor.processMatches(new FileInputStream("semicolon.txt"),
			       System.out);
    } catch(IOException e) {
      e.printStackTrace();
      System.exit(1);
    }
  }

}