1 /**
2 * Copyright (C) 2005-2009 Alfresco Software Limited.
3 *
4 * This file is part of the Spring Surf Extension project.
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.springframework.extensions.surf.util;
20
21 import java.net.URL;
22
23 /**
24 * Class containing debugging utility methods
25 *
26 * @author gavinc
27 */
28 public class Debug
29 {
30 /**
31 * Returns the location of the file that will be loaded for the given class name
32 *
33 * @param className The class to load
34 * @return The location of the file that will be loaded
35 * @throws ClassNotFoundException
36 */
37 public static String whichClass(String className) throws ClassNotFoundException
38 {
39 String path = className;
40
41 // prepare the resource path
42 if (path.startsWith("/") == false)
43 {
44 path = "/" + path;
45 }
46 path = path.replace('.', '/');
47 path = path + ".class";
48
49 // get the location
50 URL url = Debug.class.getResource(path);
51 if (url == null)
52 {
53 throw new ClassNotFoundException(className);
54 }
55
56 // format the result
57 String location = url.toExternalForm();
58 if (location.startsWith("jar"))
59 {
60 location = location.substring(10, location.lastIndexOf("!"));
61 }
62 else if (location.startsWith("file:"))
63 {
64 location = location.substring(6);
65 }
66
67 return location;
68 }
69
70 /**
71 * Returns the class loader that will load the given class name
72 *
73 * @param className The class to load
74 * @return The class loader the class will be loaded in
75 * @throws ClassNotFoundException
76 */
77 public static String whichClassLoader(String className) throws ClassNotFoundException
78 {
79 String result = "Could not determine class loader for " + className;
80
81 Class clazz = Class.forName(className);
82 ClassLoader loader = clazz.getClassLoader();
83
84 if (loader != null)
85 {
86 result = clazz.getClassLoader().toString();
87 }
88
89 return result;
90 }
91
92 /**
93 * Returns the class loader hierarchy that will load the given class name
94 *
95 * @param className The class to load
96 * @return The hierarchy of class loaders used to load the class
97 * @throws ClassNotFoundException
98 */
99 public static String whichClassLoaderHierarchy(String className) throws ClassNotFoundException
100 {
101 StringBuffer buffer = new StringBuffer();
102 Class clazz = Class.forName(className);
103 ClassLoader loader = clazz.getClassLoader();
104 if (loader != null)
105 {
106 buffer.append(loader.toString());
107
108 ClassLoader parent = loader.getParent();
109 while (parent != null)
110 {
111 buffer.append("\n-> ").append(parent.toString());
112 parent = parent.getParent();
113 }
114 }
115 else
116 {
117 buffer.append("Could not determine class loader for " + className);
118 }
119
120 return buffer.toString();
121 }
122 }