aboutsummaryrefslogtreecommitdiff
path: root/velocity-engine-core/src/main/java/org/apache/velocity/runtime/parser/node/PropertyExecutor.java
blob: 7763724c67212022f18a7062762bd4f79ef0e205 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
package org.apache.velocity.runtime.parser.node;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.apache.commons.lang3.StringUtils;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.util.ArrayListWrapper;
import org.apache.velocity.util.introspection.Introspector;
import org.slf4j.Logger;

import java.lang.reflect.InvocationTargetException;

/**
 * Returned the value of object property when executed.
 */
public class PropertyExecutor extends AbstractExecutor
{
    private final Introspector introspector;
    private final boolean wrapArray;

    /**
     * @param log
     * @param introspector
     * @param clazz
     * @param property
     * @since 1.5
     */
    public PropertyExecutor(final Logger log, final Introspector introspector,
                            final Class<?> clazz, final String property)
    {
        this(log, introspector, clazz, property, false);
    }

    /**
     * @param log
     * @param introspector
     * @param clazz
     * @param property
     * @param wrapArray
     * @since 1.5
     */
    public PropertyExecutor(final Logger log, final Introspector introspector,
            final Class<?> clazz, final String property, final boolean wrapArray)
    {
        this.log = log;
        this.introspector = introspector;
        this.wrapArray = wrapArray;

        // Don't allow passing in the empty string or null because
        // it will either fail with a StringIndexOutOfBounds error
        // or the introspector will get confused.
        if (StringUtils.isNotEmpty(property))
        {
            discover(clazz, property);
        }
    }

    /**
     * @return The current introspector.
     * @since 1.5
     */
    protected Introspector getIntrospector()
    {
        return this.introspector;
    }

    /**
     * @param clazz
     * @param property
     */
    protected void discover(final Class<?> clazz, final String property)
    {
        /*
         *  this is gross and linear, but it keeps it straightforward.
         */

        try
        {
            Object [] params = {};

            StringBuilder sb = new StringBuilder("get");
            sb.append(property);

            setMethod(introspector.getMethod(clazz, sb.toString(), params));

            if (!isAlive())
            {
                /*
                 *  now the convenience, flip the 1st character
                 */

                char c = sb.charAt(3);

                if (Character.isLowerCase(c))
                {
                    sb.setCharAt(3, Character.toUpperCase(c));
                }
                else
                {
                    sb.setCharAt(3, Character.toLowerCase(c));
                }

                setMethod(introspector.getMethod(clazz, sb.toString(), params));
            }
        }
        /*
         * pass through application level runtime exceptions
         */
        catch( RuntimeException e )
        {
            throw e;
        }
        catch(Exception e)
        {
            String msg = "Exception while looking for property getter for '" + property;
            log.error(msg, e);
            throw new VelocityException(msg, e);
        }
    }

    /**
     * @see org.apache.velocity.runtime.parser.node.AbstractExecutor#execute(java.lang.Object)
     */
    @Override
    public Object execute(Object o)
        throws IllegalAccessException,  InvocationTargetException
    {
        if (wrapArray)
        {
            o = new ArrayListWrapper(o);
        }
        return isAlive() ? getMethod().invoke(o, ((Object []) null)) : null;
    }
}