1 package org.apache.velocity.util.introspection;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Iterator;
23
24 import org.apache.velocity.runtime.RuntimeServices;
25 import org.apache.velocity.util.RuntimeServicesAware;
26
27 /**
28 * <p>
29 * When the runtime.introspection.uberspect configuration property contains several
30 * uberspector class names, it means those uberspectors will be chained. When an
31 * uberspector in the list other than the leftmost does not implement ChainableUberspector,
32 * then this utility class is used to provide a basic default chaining where the
33 * first non-null result is kept for each introspection call.
34 * </p>
35 *
36 * @since 1.6
37 * @see ChainableUberspector
38 * @version $Id: LinkingUberspector.java 10959 2008-07-01 00:12:29Z sdumitriu $
39 */
40 public class LinkingUberspector extends AbstractChainableUberspector
41 {
42 private Uberspect leftUberspect;
43 private Uberspect rightUberspect;
44
45 /**
46 * Constructor that takes the two uberspectors to link
47 */
48 public LinkingUberspector(Uberspect left,Uberspect right) {
49 leftUberspect = left;
50 rightUberspect = right;
51 }
52
53 /**
54 * {@inheritDoc}
55 * <p>
56 * Init both wrapped uberspectors
57 * </p>
58 *
59 * @see org.apache.velocity.util.introspection.Uberspect#init()
60 */
61 //@Override
62 public void init() throws Exception
63 {
64 leftUberspect.init();
65 rightUberspect.init();
66 }
67
68 /**
69 * {@inheritDoc}
70 *
71 * @see org.apache.velocity.util.introspection.Uberspect#getIterator(java.lang.Object,
72 * org.apache.velocity.util.introspection.Info)
73 */
74 //@SuppressWarnings("unchecked")
75 //@Override
76 public Iterator getIterator(Object obj, Info i) throws Exception
77 {
78 Iterator it = leftUberspect.getIterator(obj,i);
79 return it != null ? it : rightUberspect.getIterator(obj,i);
80 }
81
82 /**
83 * {@inheritDoc}
84 *
85 * @see org.apache.velocity.util.introspection.Uberspect#getMethod(java.lang.Object, java.lang.String,
86 * java.lang.Object[], org.apache.velocity.util.introspection.Info)
87 */
88 //@Override
89 public VelMethod getMethod(Object obj, String methodName, Object[] args, Info i) throws Exception
90 {
91 VelMethod method = leftUberspect.getMethod(obj,methodName,args,i);
92 return method != null ? method : rightUberspect.getMethod(obj,methodName,args,i);
93 }
94
95 /**
96 * {@inheritDoc}
97 *
98 * @see org.apache.velocity.util.introspection.Uberspect#getPropertyGet(java.lang.Object, java.lang.String,
99 * org.apache.velocity.util.introspection.Info)
100 */
101 //@Override
102 public VelPropertyGet getPropertyGet(Object obj, String identifier, Info i) throws Exception
103 {
104 VelPropertyGet getter = leftUberspect.getPropertyGet(obj,identifier,i);
105 return getter != null ? getter : rightUberspect.getPropertyGet(obj,identifier,i);
106 }
107
108 /**
109 * {@inheritDoc}
110 *
111 * @see org.apache.velocity.util.introspection.Uberspect#getPropertySet(java.lang.Object, java.lang.String,
112 * java.lang.Object, org.apache.velocity.util.introspection.Info)
113 */
114 //@Override
115 public VelPropertySet getPropertySet(Object obj, String identifier, Object arg, Info i) throws Exception
116 {
117 VelPropertySet setter = leftUberspect.getPropertySet(obj,identifier,arg,i);
118 return setter != null ? setter : rightUberspect.getPropertySet(obj,identifier,arg,i);
119 }
120 }