001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
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010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.svl.vars;
014
015import static org.apache.juneau.common.internal.ArgUtils.*;
016
017import org.apache.juneau.svl.*;
018
019/**
020 * A transformational variable resolver that replaces matched patterns with given characters.
021 *
022 * <p>
023 * The format for this var is:
024 * <ul>
025 *    <li><js>"$PR{stringArg,pattern,replace}"</js>
026 * </ul>
027 *
028 * <p>
029 * The pattern can be any string optionally containing <js>'*'</js> or <js>'?'</js> representing any or one character
030 * respectively.
031 *
032 * The replace can contain matched regex sub classes like \$1, \$2 ..
033 *
034 * <h5 class='section'>Example:</h5>
035 * <p class='bjava'>
036 *    <jc>// Create a variable resolver that resolves system properties and $SW vars.</jc>
037 *    VarResolver <jv>varResolver</jv> = VarResolver.<jsm>create</jsm>().vars(PatternReplaceVar.<jk>class</jk>, SystemPropertiesVar.<jk>class</jk>).build();
038 *
039 *    <jc>// Use it!</jc>
040 *    System.<jsf>out</jsf>.println(<jv>varResolver</jv>.resolve(<js>"Java version=$PR{$S{java.version}, (_([0-9]+)), \\ build=\\$2}"</js>));
041 * </p>
042 *
043 * <p>
044 * Since this is a {@link MultipartVar}, any variables contained in the result will be recursively resolved.
045 * <br>Likewise, if the arguments contain any variables, those will be resolved before they are passed to this var.
046 *
047 * <h5 class='section'>See Also:</h5><ul>
048 *    <li class='link'><a class="doclink" href="../../../../../index.html#jm.SimpleVariableLanguage">Simple Variable Language</a>
049 * </ul>
050 */
051public class PatternReplaceVar extends MultipartVar {
052
053   /** The name of this variable. */
054   public static final String NAME = "PR";
055
056   /**
057    * Constructor.
058    */
059   public PatternReplaceVar() {
060      super(NAME);
061   }
062
063   @Override /* MultipartVar */
064   public String resolve(VarResolverSession session, String[] args) {
065      assertArg(args.length >= 3, "Invalid number of arguments passed to $PR var.  Must have 3 or more arguments.");
066
067      String stringArg = args[0];
068      String pattern = args[1];
069      String replace = args[2];
070
071      pattern = pattern.replace("*", ".*").replace("?", ".");
072      return stringArg.replaceAll(pattern, replace);
073   }
074}