// Copyright 2004, 2005 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.tapestry.util;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.MatchResult;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternCompiler;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.PatternMatcherInput;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;
/**
* Streamlines the interface to ORO by implicitly constructing the necessary compilers and matchers,
* and by caching compiled patterns.
*
* @author Howard Lewis Ship
* @since 3.0
*/
public class RegexpMatcher
{
private PatternCompiler _patternCompiler;
private PatternMatcher _matcher;
private Map _compiledPatterns = new HashMap();
private Map _escapedPatternStrings = new HashMap();
protected Pattern compilePattern(String pattern)
{
if (_patternCompiler == null)
_patternCompiler = new Perl5Compiler();
try
{
return _patternCompiler.compile(pattern, Perl5Compiler.SINGLELINE_MASK | Perl5Compiler.READ_ONLY_MASK);
}
catch (MalformedPatternException ex)
{
throw new ApplicationRuntimeException(ex);
}
}
protected Pattern getCompiledPattern(String pattern)
{
Pattern result = (Pattern) _compiledPatterns.get(pattern);
if (result == null)
{
result = compilePattern(pattern);
_compiledPatterns.put(pattern, result);
}
return result;
}
/**
* Clears any previously compiled patterns.
*/
public void clear()
{
_compiledPatterns.clear();
}
protected PatternMatcher getPatternMatcher()
{
if (_matcher == null)
_matcher = new Perl5Matcher();
return _matcher;
}
public boolean matches(String pattern, String input)
{
Pattern compiledPattern = getCompiledPattern(pattern);
return getPatternMatcher().matches(input, compiledPattern);
}
public boolean contains(String pattern, String input)
{
Pattern compiledPattern = getCompiledPattern(pattern);
return getPatternMatcher().contains(input, compiledPattern);
}
public String getEscapedPatternString(String pattern)
{
String result = (String) _escapedPatternStrings.get(pattern);
if (result == null)
{
result = Perl5Compiler.quotemeta(pattern);
_escapedPatternStrings.put(pattern, result);
}
return result;
}
/**
* Given an input string, finds all matches in an input string for the pattern.
*
* @param pattern
* the regexp pattern for matching
* @param input
* the string to search for matches within
* @return array (possibly empty) of matches
* @since 4.0
*/
public RegexpMatch[] getMatches(String pattern, String input)
{
Pattern compiledPattern = getCompiledPattern(pattern);
PatternMatcher matcher = getPatternMatcher();
PatternMatcherInput matcherInput = new PatternMatcherInput(input);
List matches = new ArrayList();
while (matcher.contains(matcherInput, compiledPattern))
{
MatchResult match = matcher.getMatch();
matches.add(new RegexpMatch(match));
}
return (RegexpMatch[]) matches.toArray(new RegexpMatch[matches.size()]);
}
/**
* Given an input string, finds all matches in an input string for the pattern.
*
* @param pattern
* the regexp pattern for matching
* @param input
* the string to search for matches within
* @param subgroup
* the group (sub-expression) within the pattern to return as a match
* @return array (possibly empty) of matching strings
*/
public String[] getMatches(String pattern, String input, int subgroup)
{
Pattern compiledPattern = getCompiledPattern(pattern);
PatternMatcher matcher = getPatternMatcher();
PatternMatcherInput matcherInput = new PatternMatcherInput(input);
List matches = new ArrayList();
while (matcher.contains(matcherInput, compiledPattern))
{
MatchResult match = matcher.getMatch();
String matchedInput = match.group(subgroup);
matches.add(matchedInput);
}
return (String[]) matches.toArray(new String[matches.size()]);
}
}