/*
* Copyright 2000,2002-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.tools.ant.util;
import java.util.Vector;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.util.regexp.RegexpMatcher;
import org.apache.tools.ant.util.regexp.RegexpMatcherFactory;
/**
* Implementation of FileNameMapper that does regular expression
* replacements.
*
* @author Stefan Bodewig
*/
public class RegexpPatternMapper implements FileNameMapper {
protected RegexpMatcher reg = null;
protected char[] to = null;
protected StringBuffer result = new StringBuffer();
public RegexpPatternMapper() throws BuildException {
reg = (new RegexpMatcherFactory()).newRegexpMatcher();
}
/**
* Sets the "from" pattern. Required.
*/
public void setFrom(String from) throws BuildException {
try {
reg.setPattern(from);
} catch (NoClassDefFoundError e) {
// depending on the implementation the actual RE won't
// get instantiated in the constructor.
throw new BuildException("Cannot load regular expression matcher",
e);
}
}
/**
* Sets the "to" pattern. Required.
*/
public void setTo(String to) {
this.to = to.toCharArray();
}
/**
* Returns null if the source file name doesn't match the
* "from" pattern, an one-element array containing the
* translated file otherwise.
*/
public String[] mapFileName(String sourceFileName) {
if (reg == null || to == null
|| !reg.matches(sourceFileName)) {
return null;
}
return new String[] {replaceReferences(sourceFileName)};
}
/**
* Replace all backreferences in the to pattern with the matched
* groups of the source.
*/
protected String replaceReferences(String source) {
Vector v = reg.getGroups(source);
result.setLength(0);
for (int i = 0; i < to.length; i++) {
if (to[i] == '\\') {
if (++i < to.length) {
int value = Character.digit(to[i], 10);
if (value > -1) {
result.append((String) v.elementAt(value));
} else {
result.append(to[i]);
}
} else {
// XXX - should throw an exception instead?
result.append('\\');
}
} else {
result.append(to[i]);
}
}
return result.substring(0);
}
}