1 /*
2 * Copyright (c) 2005, Henri Yandell
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or
6 * without modification, are permitted provided that the
7 * following conditions are met:
8 *
9 * + Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 *
12 * + Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
14 * and/or other materials provided with the distribution.
15 *
16 * + Neither the name of Simple-JNDI nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 package org.osjava.sj.loader.convert;
34
35 import java.util.Properties;
36
37 import java.lang.reflect.Constructor;
38 import java.lang.reflect.InvocationTargetException;
39
40 /***
41 * Convert a text value to any object whose constructor
42 * takes a single String object.
43 *
44 * For example, to get an Integer object for the lookup key
45 * <i>com.example.Foo</i> you would have a com/example.properties
46 * file containing the following three lines.
47 *
48 * <pre>
49 * Foo=42
50 * Foo.type=java.lang.Integer
51 * Foo.converter=org.osjava.sj.loader.convert.Constructor
52 * </pre>
53 */
54 public class ConstructorConverter implements Converter {
55
56 public Object convert(Properties properties, String type) {
57 String value = properties.getProperty("");
58
59 if(value == null) {
60 throw new RuntimeException("Missing value");
61 }
62
63 try {
64 Class c = Class.forName(type);
65 Constructor con = c.getConstructor( new Class[] { String.class } );
66 return con.newInstance( new Object[] { value } );
67 } catch(ClassNotFoundException cnfe) {
68 throw new RuntimeException("Unable to find class: "+type, cnfe);
69 } catch(NoSuchMethodException nsme) {
70 throw new RuntimeException("Unable to find (String) constructor on class: "+type, nsme);
71 } catch(InstantiationException ie) {
72 throw new RuntimeException("Unable to instantiate class: "+type, ie);
73 } catch(IllegalAccessException ie) {
74 throw new RuntimeException("Unable to access class: "+type, ie);
75 } catch(IllegalArgumentException iae) {
76 throw new RuntimeException("Unable to pass argument "+value+" to class: "+type, iae);
77 } catch(InvocationTargetException ite) {
78 throw new RuntimeException("Unable to invoke (String) constructor on class: "+type, ite);
79 }
80
81 }
82
83 }