1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.logging;
18
19 import java.lang.reflect.InvocationTargetException;
20
21 import junit.framework.TestCase;
22
23 /**
24 * test to emulate container and application isolated from container
25 */
26 public class LoadTestCase extends TestCase {
27
28 /**
29 * A custom class loader which "duplicates" logging classes available
30 * in the parent class loader into itself.
31 * <p>
32 * When asked to load a class that is in one of the LOG_PCKG packages,
33 * it loads the class itself (child-first). This class doesn't need
34 * to be set up with a classpath, as it simply uses the same classpath
35 * as the class loader that loaded it.
36 */
37 static class AppClassLoader extends ClassLoader {
38
39 java.util.Map classes = new java.util.HashMap();
40
41 AppClassLoader(final ClassLoader parent) {
42 super(parent);
43 }
44
45 private Class<?> def(final String name) throws ClassNotFoundException {
46
47 Class<?> result = (Class<?>) classes.get(name);
48 if (result != null) {
49 return result;
50 }
51
52 try {
53
54 final ClassLoader cl = this.getClass().getClassLoader();
55 final String classFileName = name.replace('.', '/') + ".class";
56 final java.io.InputStream is = cl.getResourceAsStream(classFileName);
57 final java.io.ByteArrayOutputStream out = new java.io.ByteArrayOutputStream();
58
59 while (is.available() > 0) {
60 out.write(is.read());
61 }
62
63 final byte[] data = out.toByteArray();
64
65 result = super.defineClass(name, data, 0, data.length);
66 classes.put(name, result);
67
68 return result;
69
70 } catch (final java.io.IOException ioe) {
71
72 throw new ClassNotFoundException(name + " caused by " + ioe.getMessage());
73 }
74
75 }
76
77 // not very trivial to emulate we must implement "findClass",
78 // but it will delegate to JUnit class loader first
79 @Override
80 public Class loadClass(final String name) throws ClassNotFoundException {
81
82 // isolates all logging classes, application in the same class loader too.
83 // filters exceptions to simplify handling in test
84 for (final String element : LOG_PCKG) {
85 if (name.startsWith(element) && name.indexOf("Exception") == -1) {
86 return def(name);
87 }
88 }
89 return super.loadClass(name);
90 }
91
92 }
93
94 //TODO: need some way to add service provider packages
95 static private String[] LOG_PCKG = {"org.apache.commons.logging",
96 "org.apache.commons.logging.impl"};
97
98 private ClassLoader origContextClassLoader;
99
100 private void execute(final Class cls) throws Exception {
101 cls.getConstructor().newInstance();
102 }
103
104 /**
105 * Load class UserClass via a temporary class loader which is a child of
106 * the class loader used to load this test class.
107 */
108 private Class reload() throws Exception {
109 Class testObjCls = null;
110 final AppClassLoader appLoader = new AppClassLoader(this.getClass().getClassLoader());
111 try {
112
113 testObjCls = appLoader.loadClass(UserClass.class.getName());
114
115 } catch (final ClassNotFoundException cnfe) {
116 throw cnfe;
117 } catch (final Throwable t) {
118 t.printStackTrace();
119 fail("AppClassLoader failed ");
120 }
121
122 assertSame("app isolated", testObjCls.getClassLoader(), appLoader);
123
124 return testObjCls;
125
126 }
127
128 /**
129 * Call the static setAllowFlawedContext method on the specified class
130 * (expected to be a UserClass loaded via a custom class loader), passing
131 * it the specified state parameter.
132 */
133 private void setAllowFlawedContext(final Class<?> c, final String state) throws Exception {
134 final Class<?>[] params = {String.class};
135 final java.lang.reflect.Method m = c.getDeclaredMethod("setAllowFlawedContext", params);
136 m.invoke(null, state);
137 }
138
139 @Override
140 public void setUp() {
141 // save state before test starts so we can restore it when test ends
142 origContextClassLoader = Thread.currentThread().getContextClassLoader();
143 }
144
145 @Override
146 public void tearDown() {
147 // restore original state so a test can't stuff up later tests.
148 Thread.currentThread().setContextClassLoader(origContextClassLoader);
149 }
150
151 /**
152 * Test what happens when we play various class loader tricks like those
153 * that happen in web and j2ee containers.
154 * <p>
155 * Note that this test assumes that commons-logging.jar and log4j.jar
156 * are available via the system classpath.
157 */
158 public void testInContainer() throws Exception {
159
160 //problem can be in this step (broken app container or missconfiguration)
161 //1. Thread.currentThread().setContextClassLoader(ClassLoader.getSystemClassLoader());
162 //2. Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
163 // we expect this :
164 // 1. Thread.currentThread().setContextClassLoader(appLoader);
165 // 2. Thread.currentThread().setContextClassLoader(null);
166
167 // Context class loader is same as class calling into log
168 Class<?> cls = reload();
169 Thread.currentThread().setContextClassLoader(cls.getClassLoader());
170 execute(cls);
171
172 // Context class loader is the "bootclass loader". This is technically
173 // bad, but LogFactoryImpl.ALLOW_FLAWED_CONTEXT defaults to true so
174 // this test should pass.
175 cls = reload();
176 Thread.currentThread().setContextClassLoader(null);
177 execute(cls);
178
179 // Context class loader is the "bootclass loader". This is same as above
180 // except that ALLOW_FLAWED_CONTEXT is set to false; an error should
181 // now be reported.
182 cls = reload();
183 Thread.currentThread().setContextClassLoader(null);
184 try {
185 setAllowFlawedContext(cls, "false");
186 execute(cls);
187 fail("Logging config succeeded when context class loader was null!");
188 } catch (final InvocationTargetException ex) {
189 final Throwable targetException = ex.getTargetException();
190 // LogConfigurationException is expected; the boot class loader doesn't *have* JCL available
191 if (!(targetException instanceof LogConfigurationException)) {
192 throw ex;
193 }
194 }
195
196 // Context class loader is the system class loader.
197 //
198 // This is expected to cause problems, as LogFactoryImpl will attempt
199 // to use the system class loader to load the Log4JLogger class, which
200 // will then be unable to cast that object to the Log interface loaded
201 // via the child class loader. However as ALLOW_FLAWED_CONTEXT defaults
202 // to true this test should pass.
203 cls = reload();
204 Thread.currentThread().setContextClassLoader(ClassLoader.getSystemClassLoader());
205 execute(cls);
206
207 // Context class loader is the system class loader. This is the same
208 // as above except that ALLOW_FLAWED_CONTEXT is set to false; an error
209 // should now be reported.
210 cls = reload();
211 Thread.currentThread().setContextClassLoader(ClassLoader.getSystemClassLoader());
212 try {
213 setAllowFlawedContext(cls, "false");
214 execute(cls);
215 fail("Error: somehow downcast a Logger loaded via system class loader"
216 + " to the Log interface loaded via a custom class loader");
217 } catch (final InvocationTargetException ex) {
218 final Throwable targetException = ex.getTargetException();
219 // LogConfigurationException is expected
220 if (!(targetException instanceof LogConfigurationException)) {
221 throw ex;
222 }
223 }
224 }
225 }