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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      protected final String toText(Object value) {
63          StringBuilder buf = new StringBuilder();
64          for (Object v : (Collection<?>) value) {
65              if (v == null) {
66                  v = defaultElement();
67              }
68  
69              PropertyEditor e = PropertyEditorFactory.getInstance(v);
70              if (e == null) {
71                  throw new IllegalArgumentException("No " + PropertyEditor.class.getSimpleName() + " found for "
72                          + v.getClass().getSimpleName() + '.');
73              }
74              e.setValue(v);
75              // TODO normalize.
76              String s = e.getAsText();
77              buf.append(s);
78              buf.append(", ");
79          }
80  
81          // Remove the last delimiter.
82          if (buf.length() >= 2) {
83              buf.setLength(buf.length() - 2);
84          }
85          return buf.toString();
86      }
87  
88      @Override
89      protected final Object toValue(String text) throws IllegalArgumentException {
90          PropertyEditor e = getElementEditor();
91          Collection<Object> answer = newCollection();
92          Matcher m = ELEMENT.matcher(text);
93          boolean matchedDelimiter = true;
94  
95          while (m.find()) {
96              if (m.group(1) != null) {
97                  matchedDelimiter = true;
98                  continue;
99              }
100 
101             if (!matchedDelimiter) {
102                 throw new IllegalArgumentException("No delimiter between elements: " + text);
103             }
104 
105             // TODO escape here.
106             e.setAsText(m.group());
107             answer.add(e.getValue());
108 
109             matchedDelimiter = false;
110             if (m.group(2) != null || m.group(3) != null) {
111                 // Skip the last '"'.
112                 m.region(m.end() + 1, m.regionEnd());
113             }
114         }
115 
116         return answer;
117     }
118 
119     protected Collection<Object> newCollection() {
120         return new ArrayList<Object>();
121     }
122 
123     protected Object defaultElement() {
124         PropertyEditor e = PropertyEditorFactory.getInstance(elementType);
125         if (e == null) {
126             return null;
127         }
128 
129         if (e instanceof AbstractPropertyEditor) {
130             return ((AbstractPropertyEditor) e).defaultValue();
131         }
132 
133         return null;
134     }
135 }