/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* 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 com.alibaba.citrus.util.regex;
import static com.alibaba.citrus.util.ArrayUtil.*;
import static com.alibaba.citrus.util.Assert.*;
import java.util.regex.MatchResult;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import com.alibaba.citrus.util.ToStringBuilder;
import com.alibaba.citrus.util.ToStringBuilder.MapBuilder;
/**
* 用<code>MatchResult</code>来替换字符串中的变量。通常变量以<code>'$'</code>开始，例如：
* <code>$1</code>，<code>$2</code>等，但<code>MatchResultSubstitution</code>类支持对多个
* <code>MatchResult</code>变量进行替换，分别对应不同的前缀。
*
* @author Michael Zhou
*/
public class MatchResultSubstitution extends Substitution {
/** 代表一个成功但无内容的匹配结果。 */
public static final MatchResult EMPTY_MATCH_RESULT = createEmptyMatchResult();
private final MatchResult[] results;
private static MatchResult createEmptyMatchResult() {
Matcher matcher = Pattern.compile("^$").matcher("");
assertTrue(matcher.find());
return matcher.toMatchResult();
}
/** 创建一个替换。替换所有<code>$num</code>所代表的变量。 */
public MatchResultSubstitution() {
this("$", EMPTY_MATCH_RESULT);
}
/** 创建一个替换。替换所有<code>$num</code>所代表的变量。 */
public MatchResultSubstitution(MatchResult result) {
this("$", result);
}
/** 设置新匹配。 */
public void setMatchResult(MatchResult result) {
if (results.length != 1) {
new IllegalArgumentException("expected " + this.results.length + " MatchResults");
}
results[0] = result;
}
/** 设置新匹配。 */
public void setMatchResults(MatchResult... results) {
assertTrue(!isEmptyArray(results), "results");
if (this.results.length != results.length) {
throw new IllegalArgumentException("expected " + this.results.length + " MatchResults");
}
for (int i = 0; i < results.length; i++) {
this.results[i] = results[i];
}
}
/** 创建一个替换。将所有指定前缀所代表的变量替换成相应<code>MatchResult.group(num)</code>的值。 */
public MatchResultSubstitution(String replacementPrefixes, MatchResult... results) {
super(replacementPrefixes);
this.results = new MatchResult[this.replacementPrefixes.length()];
setMatchResults(results);
}
/** 取得匹配。 */
public MatchResult getMatch() {
return getMatch(0);
}
/** 取得匹配。 */
public MatchResult getMatch(int index) {
return results[index];
}
@Override
protected String group(int index, int groupNumber) {
MatchResult result = getMatch(index);
if (groupNumber <= result.groupCount()) {
return result.group(groupNumber);
}
return null;
}
@Override
public String toString() {
MapBuilder mb = new MapBuilder();
for (int i = 0; i < replacementPrefixes.length(); i++) {
mb.append(replacementPrefixes.charAt(i) + "n", results[i]);
}
return new ToStringBuilder().append(getClass().getSimpleName()).append(mb).toString();
}
}