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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    * 
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   * 
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.mina.integration.ognl;
18  
19  import java.util.Map;
20  
21  import ognl.ObjectPropertyAccessor;
22  import ognl.OgnlContext;
23  import ognl.OgnlException;
24  import ognl.OgnlRuntime;
25  import ognl.PropertyAccessor;
26  
27  /**
28   * An abstract OGNL {@link PropertyAccessor} for MINA constructs.
29   * 
30   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
31   */
32  @SuppressWarnings("unchecked")
33  public abstract class AbstractPropertyAccessor extends ObjectPropertyAccessor {
34  
35      static final Object READ_ONLY_MODE = new Object();
36  
37      static final Object QUERY = new Object();
38  
39      @Override
40      public final boolean hasGetProperty(OgnlContext context, Object target, Object oname) throws OgnlException {
41          if (oname == null) {
42              return false;
43          }
44  
45          if (hasGetProperty0(context, target, oname.toString())) {
46              return true;
47          } else {
48              return super.hasGetProperty(context, target, oname);
49          }
50      }
51  
52      @Override
53      public final boolean hasSetProperty(OgnlContext context, Object target, Object oname) throws OgnlException {
54          if (context.containsKey(READ_ONLY_MODE)) {
55              // Return true to trigger setPossibleProperty to throw an exception.
56              return true;
57          }
58  
59          if (oname == null) {
60              return false;
61          }
62  
63          if (hasSetProperty0(context, target, oname.toString())) {
64              return true;
65          } else {
66              return super.hasSetProperty(context, target, oname);
67          }
68      }
69  
70      @Override
71      public final Object getPossibleProperty(Map context, Object target, String name) throws OgnlException {
72          Object answer = getProperty0((OgnlContext) context, target, name);
73          if (answer == OgnlRuntime.NotFound) {
74              answer = super.getPossibleProperty(context, target, name);
75          }
76          return answer;
77      }
78  
79      @Override
80      public final Object setPossibleProperty(Map context, Object target, String name, Object value) throws OgnlException {
81          if (context.containsKey(READ_ONLY_MODE)) {
82              throw new OgnlException("Expression must be read-only: " + context.get(QUERY));
83          }
84  
85          Object answer = setProperty0((OgnlContext) context, target, name, value);
86          if (answer == OgnlRuntime.NotFound) {
87              answer = super.setPossibleProperty(context, target, name, value);
88          }
89          return answer;
90      }
91  
92      protected abstract boolean hasGetProperty0(OgnlContext context, Object target, String name) throws OgnlException;
93  
94      protected abstract boolean hasSetProperty0(OgnlContext context, Object target, String name) throws OgnlException;
95  
96      protected abstract Object getProperty0(OgnlContext context, Object target, String name) throws OgnlException;
97  
98      protected abstract Object setProperty0(OgnlContext context, Object target, String name, Object value)
99              throws OgnlException;
100 
101     // The following methods uses the four method above, so there's no need
102     // to override them.
103 
104     @Override
105     public final Object getProperty(Map context, Object target, Object oname) throws OgnlException {
106         return super.getProperty(context, target, oname);
107     }
108 
109     @Override
110     public final boolean hasGetProperty(Map context, Object target, Object oname) throws OgnlException {
111         return super.hasGetProperty(context, target, oname);
112     }
113 
114     @Override
115     public final boolean hasSetProperty(Map context, Object target, Object oname) throws OgnlException {
116         return super.hasSetProperty(context, target, oname);
117     }
118 
119     @Override
120     public final void setProperty(Map context, Object target, Object oname, Object value) throws OgnlException {
121         super.setProperty(context, target, oname, value);
122     }
123 }