Java tutorial
/* * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 1999-2003 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. 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For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.commons.jrcs.diff; import java.util.ArrayList; import java.util.Arrays; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.ListIterator; import org.apache.commons.jrcs.util.ToString; /** * A Revision holds the series of deltas that describe the differences between * two sequences. * * @version $Revision$ $Date: 2006-04-12 18:30:19 +0100 (Wed, 12 Apr * 2006) $ * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a> * @author <a href="mailto:bwm@hplb.hpl.hp.com">Brian McBride</a> * @see Delta * @see Diff * @see Chunk * @see Revision modifications 27 Apr 2003 bwm Added visitor pattern Visitor * interface and accept() method. */ public class Revision extends ToString { List deltas_ = new LinkedList(); /** * Creates an empty Revision. */ public Revision() { } /** * Adds a delta to this revision. * * @param delta * the {@link Delta Delta} to add. */ public synchronized void addDelta(Delta delta) { if (delta == null) { throw new IllegalArgumentException("new delta is null"); } deltas_.add(delta); } /** * Adds a delta to the start of this revision. * * @param delta * the {@link Delta Delta} to add. */ public synchronized void insertDelta(Delta delta) { if (delta == null) { throw new IllegalArgumentException("new delta is null"); } deltas_.add(0, delta); } /** * Retrieves a delta from this revision by position. * * @param i * the position of the delta to retrieve. * @return the specified delta */ public Delta getDelta(int i) { return (Delta) deltas_.get(i); } /** * Returns the number of deltas in this revision. * * @return the number of deltas. */ public int size() { return deltas_.size(); } /** * Applies the series of deltas in this revision as patches to the given * text. * * @param src * the text to patch, which the method doesn't change. * @return the resulting text after the patches have been applied. * @throws PatchFailedException * if any of the patches cannot be applied. */ public Object[] patch(Object[] src) throws PatchFailedException { List target = new ArrayList(Arrays.asList(src)); applyTo(target); return target.toArray(); } /** * Applies the series of deltas in this revision as patches to the given * text. * * @param target * the text to patch. * @throws PatchFailedException * if any of the patches cannot be applied. */ public synchronized void applyTo(List target) throws PatchFailedException { ListIterator i = deltas_.listIterator(deltas_.size()); while (i.hasPrevious()) { Delta delta = (Delta) i.previous(); delta.patch(target); } } /** * Converts this revision into its Unix diff style string representation. * * @param s * a {@link StringBuffer StringBuffer} to which the string * representation will be appended. */ public synchronized void toString(StringBuffer s) { Iterator i = deltas_.iterator(); while (i.hasNext()) { ((Delta) i.next()).toString(s); } } /** * Converts this revision into its RCS style string representation. * * @param s * a {@link StringBuffer StringBuffer} to which the string * representation will be appended. * @param EOL * the string to use as line separator. */ public synchronized void toRCSString(StringBuffer s, String EOL) { Iterator i = deltas_.iterator(); while (i.hasNext()) { ((Delta) i.next()).toRCSString(s, EOL); } } /** * Converts this revision into its RCS style string representation. * * @param s * a {@link StringBuffer StringBuffer} to which the string * representation will be appended. */ public void toRCSString(StringBuffer s) { toRCSString(s, Diff.NL); } /** * Converts this delta into its RCS style string representation. * * @param EOL * the string to use as line separator. */ public String toRCSString(String EOL) { StringBuffer s = new StringBuffer(); toRCSString(s, EOL); return s.toString(); } /** * Converts this delta into its RCS style string representation using the * default line separator. */ public String toRCSString() { return toRCSString(Diff.NL); } /** * Accepts a visitor. * * @param visitor * the {@link Visitor} visiting this instance */ public void accept(RevisionVisitor visitor) { visitor.visit(this); Iterator iter = deltas_.iterator(); while (iter.hasNext()) { ((Delta) iter.next()).accept(visitor); } } }