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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.integration.beans;
21  
22  import java.beans.PropertyEditor;
23  import java.util.ArrayList;
24  import java.util.Collection;
25  import java.util.regex.Matcher;
26  import java.util.regex.Pattern;
27  
28  /**
29   * A {@link PropertyEditor} which converts a {@link String} into
30   * a {@link Collection} and vice versa.
31   *
32   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
33   */
34  public class CollectionEditor extends AbstractPropertyEditor {
35      static final Pattern ELEMENT = Pattern.compile("([,\\s]+)|"
36              + // Delimiter
37              "(?<=\")((?:\\\\\"|\\\\'|\\\\\\\\|\\\\ |[^\"])*)(?=\")|"
38              + "(?<=')((?:\\\\\"|\\\\'|\\\\\\\\|\\\\ |[^'])*)(?=')|" + "((?:[^\\\\\\s'\",]|\\\\ |\\\\\"|\\\\')+)");
39  
40      private final Class<?> elementType;
41  
42      public CollectionEditor(Class<?> elementType) {
43          if (elementType == null) {
44              throw new IllegalArgumentException("elementType");
45          }
46  
47          this.elementType = elementType;
48          getElementEditor();
49          setTrimText(false);
50      }
51  
52      private PropertyEditor getElementEditor() {
53          PropertyEditor e = PropertyEditorFactory.getInstance(elementType);
54          if (e == null) {
55              throw new IllegalArgumentException("No " + PropertyEditor.class.getSimpleName() + " found for "
56                      + elementType.getSimpleName() + '.');
57          }
58          return e;
59      }
60  
61      @Override
62      @SuppressWarnings("unchecked")
63      protected final String toText(Object value) {
64          StringBuilder buf = new StringBuilder();
65          for (Object v : (Collection) value) {
66              if (v == null) {
67                  v = defaultElement();
68              }
69  
70              PropertyEditor e = PropertyEditorFactory.getInstance(v);
71              if (e == null) {
72                  throw new IllegalArgumentException("No " + PropertyEditor.class.getSimpleName() + " found for "
73                          + v.getClass().getSimpleName() + '.');
74              }
75              e.setValue(v);
76              // TODO normalize.
77              String s = e.getAsText();
78              buf.append(s);
79              buf.append(", ");
80          }
81  
82          // Remove the last delimiter.
83          if (buf.length() >= 2) {
84              buf.setLength(buf.length() - 2);
85          }
86          return buf.toString();
87      }
88  
89      @Override
90      protected final Object toValue(String text) throws IllegalArgumentException {
91          PropertyEditor e = getElementEditor();
92          Collection<Object> answer = newCollection();
93          Matcher m = ELEMENT.matcher(text);
94          boolean matchedDelimiter = true;
95  
96          while (m.find()) {
97              if (m.group(1) != null) {
98                  matchedDelimiter = true;
99                  continue;
100             }
101 
102             if (!matchedDelimiter) {
103                 throw new IllegalArgumentException("No delimiter between elements: " + text);
104             }
105 
106             // TODO escape here.
107             e.setAsText(m.group());
108             answer.add(e.getValue());
109 
110             matchedDelimiter = false;
111             if (m.group(2) != null || m.group(3) != null) {
112                 // Skip the last '"'.
113                 m.region(m.end() + 1, m.regionEnd());
114             }
115         }
116 
117         return answer;
118     }
119 
120     protected Collection<Object> newCollection() {
121         return new ArrayList<Object>();
122     }
123 
124     protected Object defaultElement() {
125         PropertyEditor e = PropertyEditorFactory.getInstance(elementType);
126         if (e == null) {
127             return null;
128         }
129 
130         if (e instanceof AbstractPropertyEditor) {
131             return ((AbstractPropertyEditor) e).defaultValue();
132         }
133 
134         return null;
135     }
136 }