001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau;
018
019import static java.lang.Character.*;
020
021import org.apache.juneau.common.utils.*;
022
023/**
024 * Converts property names to underscore-lower-case format.
025 *
026 * <h5 class='section'>Example:</h5>
027 * <ul>
028 *    <li><js>"fooBar"</js> -&gt; <js>"foo_bar"</js>
029 *    <li><js>"fooBarURL"</js> -&gt; <js>"foo_bar_url"</js>
030 *    <li><js>"FooBarURL"</js> -&gt; <js>"foo_bar_url"</js>
031 * </ul>
032 *
033 * <h5 class='section'>See Also:</h5><ul>
034
035 * </ul>
036 */
037public class PropertyNamerULC implements PropertyNamer {
038
039   /** Reusable instance. */
040   public static final PropertyNamer INSTANCE = new PropertyNamerULC();
041
042   @Override /* PropertyNamer */
043   public String getPropertyName(String name) {
044      if (Utils.isEmpty(name))
045         return name;
046
047      int numUCs = 0;
048      boolean isPrevUC = isUpperCase(name.charAt(0));
049      for (int i = 1; i < name.length(); i++) {
050         char c = name.charAt(i);
051         if (isUpperCase(c)) {
052            if (! isPrevUC)
053               numUCs++;
054            isPrevUC = true;
055         } else {
056            isPrevUC = false;
057         }
058      }
059
060      char[] name2 = new char[name.length() + numUCs];
061      isPrevUC = isUpperCase(name.charAt(0));
062      int ni = 0;
063      for (int i = 0; i < name.length(); i++) {
064         char c = name.charAt(i);
065         if (isUpperCase(c)) {
066            if (! isPrevUC)
067               name2[ni++] = '_';
068            isPrevUC = true;
069            name2[ni++] = toLowerCase(c);
070         } else {
071            isPrevUC = false;
072            name2[ni++] = c;
073         }
074      }
075
076      return new String(name2);
077   }
078}