1 package org.apache.velocity.runtime.parser.node;
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.lang.reflect.InvocationTargetException;
23
24 import org.apache.commons.lang.StringUtils;
25 import org.apache.commons.lang.text.StrBuilder;
26 import org.apache.velocity.exception.VelocityException;
27 import org.apache.velocity.runtime.log.Log;
28 import org.apache.velocity.util.introspection.Introspector;
29
30 /**
31 * Executor for looking up property names in the passed in class
32 * This will try to find a set<foo>(key, value) method
33 *
34 * @author <a href="mailto:henning@apache.org">Henning P. Schmiedehausen</a>
35 * @version $Id: SetPropertyExecutor.java 687177 2008-08-19 22:00:32Z nbubna $
36 * @since 1.5
37 */
38 public class SetPropertyExecutor
39 extends SetExecutor
40 {
41 private final Introspector introspector;
42
43 /**
44 * @param log
45 * @param introspector
46 * @param clazz
47 * @param property
48 * @param arg
49 */
50 public SetPropertyExecutor(final Log log, final Introspector introspector,
51 final Class clazz, final String property, final Object arg)
52 {
53 this.log = log;
54 this.introspector = introspector;
55
56 // Don't allow passing in the empty string or null because
57 // it will either fail with a StringIndexOutOfBounds error
58 // or the introspector will get confused.
59 if (StringUtils.isNotEmpty(property))
60 {
61 discover(clazz, property, arg);
62 }
63 }
64
65 /**
66 * @return The current introspector.
67 */
68 protected Introspector getIntrospector()
69 {
70 return this.introspector;
71 }
72
73 /**
74 * @param clazz
75 * @param property
76 * @param arg
77 */
78 protected void discover(final Class clazz, final String property, final Object arg)
79 {
80 Object [] params = new Object [] { arg };
81
82 try
83 {
84 StrBuilder sb = new StrBuilder("set");
85 sb.append(property);
86
87 setMethod(introspector.getMethod(clazz, sb.toString(), params));
88
89 if (!isAlive())
90 {
91 /*
92 * now the convenience, flip the 1st character
93 */
94
95 char c = sb.charAt(3);
96
97 if (Character.isLowerCase(c))
98 {
99 sb.setCharAt(3, Character.toUpperCase(c));
100 }
101 else
102 {
103 sb.setCharAt(3, Character.toLowerCase(c));
104 }
105
106 setMethod(introspector.getMethod(clazz, sb.toString(), params));
107 }
108 }
109 /**
110 * pass through application level runtime exceptions
111 */
112 catch( RuntimeException e )
113 {
114 throw e;
115 }
116 catch(Exception e)
117 {
118 String msg = "Exception while looking for property setter for '" + property;
119 log.error(msg, e);
120 throw new VelocityException(msg, e);
121 }
122 }
123
124 /**
125 * Execute method against context.
126 * @param o
127 * @param value
128 * @return The value of the invocation.
129 * @throws IllegalAccessException
130 * @throws InvocationTargetException
131 */
132 public Object execute(final Object o, final Object value)
133 throws IllegalAccessException, InvocationTargetException
134 {
135 Object [] params = new Object [] { value };
136 return isAlive() ? getMethod().invoke(o, params) : null;
137 }
138 }