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Posted to dev@tomcat.apache.org by ma...@apache.org on 2020/04/12 18:48:11 UTC
[tomcat] 02/02: Rework the fix for BZ 64021 for better custom class
loader support
This is an automated email from the ASF dual-hosted git repository.
markt pushed a commit to branch 7.0.x
in repository https://gitbox.apache.org/repos/asf/tomcat.git
commit b732c45fb3550b9d83984b11bf7009b1511bffac
Author: Mark Thomas <ma...@apache.org>
AuthorDate: Sun Apr 12 19:47:22 2020 +0100
Rework the fix for BZ 64021 for better custom class loader support
https://bz.apache.org/bugzilla/show_bug.cgi?id=64021
Better support custom class loaders that load resources from
non-standard locations and do not utilise the WebResources
implementation.
---
.../catalina/startup/WebappServiceLoader.java | 116 +++++++-----
.../catalina/startup/TestWebappServiceLoader.java | 197 +++++++++++++++++++--
.../org/apache/catalina/startup/service-config.txt | 20 +++
webapps/docs/changelog.xml | 5 +
4 files changed, 279 insertions(+), 59 deletions(-)
diff --git a/java/org/apache/catalina/startup/WebappServiceLoader.java b/java/org/apache/catalina/startup/WebappServiceLoader.java
index efdf002..eb5c11e 100644
--- a/java/org/apache/catalina/startup/WebappServiceLoader.java
+++ b/java/org/apache/catalina/startup/WebappServiceLoader.java
@@ -22,14 +22,15 @@ import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
-import java.net.URLClassLoader;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
+import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
+import java.util.Set;
import java.util.regex.Pattern;
import javax.servlet.ServletContext;
@@ -68,6 +69,7 @@ public class WebappServiceLoader<T> {
private final ServletContext servletContext;
private final Pattern containerSciFilterPattern;
+
/**
* Construct a loader to load services from a ServletContext.
*
@@ -84,8 +86,14 @@ public class WebappServiceLoader<T> {
}
}
+
/**
- * Load the providers for a service type.
+ * Load the providers for a service type. Container defined services will be
+ * loaded before application defined services in case the application
+ * depends on a Container provided service. Note that services are always
+ * loaded via the Context (web application) class loader so it is possible
+ * for an application to provide an alternative implementation of what would
+ * normally be a Container provided service.
*
* @param serviceType the type of service to load
* @return an unmodifiable collection of service providers
@@ -94,24 +102,64 @@ public class WebappServiceLoader<T> {
public List<T> load(Class<T> serviceType) throws IOException {
String configFile = SERVICES + serviceType.getName();
- LinkedHashSet<String> applicationServicesFound = new LinkedHashSet<String>();
- LinkedHashSet<String> containerServicesFound = new LinkedHashSet<String>();
+ // Obtain the Container provided service configuration files.
+ ClassLoader loader = context.getParentClassLoader();
+ Enumeration<URL> containerResources;
+ if (loader == null) {
+ containerResources = ClassLoader.getSystemResources(configFile);
+ } else {
+ containerResources = loader.getResources(configFile);
+ }
+
+ // Extract the Container provided service class names. Each
+ // configuration file may list more than one service class name. This
+ // uses a LinkedHashSet so if a service class name appears more than
+ // once in the configuration files, only the first one found is used.
+ LinkedHashSet<String> containerServiceClassNames = new LinkedHashSet<String>();
+ Set<URL> containerServiceConfigFiles = new HashSet<URL>();
+ while (containerResources.hasMoreElements()) {
+ URL containerServiceConfigFile = containerResources.nextElement();
+ containerServiceConfigFiles.add(containerServiceConfigFile);
+ parseConfigFile(containerServiceClassNames, containerServiceConfigFile);
+ }
- ClassLoader loader = servletContext.getClassLoader();
+ // Filter the discovered container SCIs if required
+ if (containerSciFilterPattern != null) {
+ Iterator<String> iter = containerServiceClassNames.iterator();
+ while (iter.hasNext()) {
+ if (containerSciFilterPattern.matcher(iter.next()).find()) {
+ iter.remove();
+ }
+ }
+ }
- // if the ServletContext has ORDERED_LIBS, then use that to specify the
- // set of JARs from WEB-INF/lib that should be used for loading services
+ // Obtaining the application provided configuration files is a little
+ // more difficult for two reasons:
+ // - The web application may employ a custom class loader. Ideally, we
+ // would use ClassLoader.findResources() but that method is protected.
+ // We could force custom class loaders to override that method and
+ // make it public but that would be a new requirement and break
+ // backwards compatibility for what is an often customised component.
+ // - If the application web.xml file has defined an order for fragments
+ // then only those JAR files represented by fragments in that order
+ // (and arguably WEB-INF/classes) should be scanned for services.
+ LinkedHashSet<String> applicationServiceClassNames = new LinkedHashSet<String>();
+
+ // Check to see if the ServletContext has ORDERED_LIBS defined
@SuppressWarnings("unchecked")
List<String> orderedLibs = (List<String>) servletContext.getAttribute(ServletContext.ORDERED_LIBS);
- // Handle application SCIs directly...
+ // Obtain the application provided service configuration files
if (orderedLibs == null) {
- // No ordered libs, so use every service definition we can find
- if (loader instanceof URLClassLoader) {
- Enumeration<URL> resources = ((URLClassLoader) loader).findResources(configFile);
- while (resources.hasMoreElements()) {
- URL resource = resources.nextElement();
- parseConfigFile(applicationServicesFound, resource);
+ // Because a custom class loader may be being used, we have to use
+ // getResources() which will return application and Container files.
+ Enumeration<URL> allResources = servletContext.getClassLoader().getResources(configFile);
+ while (allResources.hasMoreElements()) {
+ URL serviceConfigFile = allResources.nextElement();
+ // Only process the service configuration file if it is not a
+ // Container level file that has already been processed
+ if (!containerServiceConfigFiles.contains(serviceConfigFile)) {
+ parseConfigFile(applicationServiceClassNames, serviceConfigFile);
}
}
} else {
@@ -119,7 +167,7 @@ public class WebappServiceLoader<T> {
// in WEB-INF/classes
URL unpacked = servletContext.getResource(CLASSES + configFile);
if (unpacked != null) {
- parseConfigFile(applicationServicesFound, unpacked);
+ parseConfigFile(applicationServiceClassNames, unpacked);
}
for (String lib : orderedLibs) {
@@ -137,48 +185,26 @@ public class WebappServiceLoader<T> {
url = UriUtil.buildJarUrl(base, configFile);
}
try {
- parseConfigFile(applicationServicesFound, url);
+ parseConfigFile(applicationServiceClassNames, url);
} catch (FileNotFoundException e) {
// no provider file found, this is OK
}
}
}
- // and use the parent ClassLoader for all other SCIs
- loader = context.getParentClassLoader();
-
- Enumeration<URL> resources;
- if (loader == null) {
- resources = ClassLoader.getSystemResources(configFile);
- } else {
- resources = loader.getResources(configFile);
- }
- while (resources.hasMoreElements()) {
- parseConfigFile(containerServicesFound, resources.nextElement());
- }
-
- // Filter the discovered container SCIs if required
- if (containerSciFilterPattern != null) {
- Iterator<String> iter = containerServicesFound.iterator();
- while (iter.hasNext()) {
- if (containerSciFilterPattern.matcher(iter.next()).find()) {
- iter.remove();
- }
- }
- }
-
// Add the application services after the container services to ensure
// that the container services are loaded first
- containerServicesFound.addAll(applicationServicesFound);
+ containerServiceClassNames.addAll(applicationServiceClassNames);
- // load the discovered services
- if (containerServicesFound.isEmpty()) {
+ // Short-cut if no services have been found
+ if (containerServiceClassNames.isEmpty()) {
return Collections.emptyList();
}
- return loadServices(serviceType, containerServicesFound);
+ // Load the discovered services
+ return loadServices(serviceType, containerServiceClassNames);
}
- private void parseConfigFile(LinkedHashSet<String> servicesFound, URL url)
+ void parseConfigFile(LinkedHashSet<String> servicesFound, URL url)
throws IOException {
InputStream is = null;
BufferedReader reader = null;
@@ -208,7 +234,7 @@ public class WebappServiceLoader<T> {
}
}
- private List<T> loadServices(Class<T> serviceType, LinkedHashSet<String> servicesFound)
+ List<T> loadServices(Class<T> serviceType, LinkedHashSet<String> servicesFound)
throws IOException {
ClassLoader loader = servletContext.getClassLoader();
List<T> services = new ArrayList<T>(servicesFound.size());
diff --git a/test/org/apache/catalina/startup/TestWebappServiceLoader.java b/test/org/apache/catalina/startup/TestWebappServiceLoader.java
index 5e30245..dddf9dc 100644
--- a/test/org/apache/catalina/startup/TestWebappServiceLoader.java
+++ b/test/org/apache/catalina/startup/TestWebappServiceLoader.java
@@ -16,27 +16,196 @@
*/
package org.apache.catalina.startup;
-import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Arrays;
import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.List;
import javax.servlet.ServletContainerInitializer;
+import javax.servlet.ServletContext;
+import org.junit.Assert;
+import org.junit.Before;
import org.junit.Test;
-import org.apache.catalina.core.StandardContext;
+import org.apache.catalina.Context;
+import org.apache.tomcat.unittest.TesterContext;
+import org.easymock.EasyMock;
+import org.easymock.IMocksControl;
+
+public class TestWebappServiceLoader {
+ private static final String CONFIG_FILE =
+ "META-INF/services/javax.servlet.ServletContainerInitializer";
+ private IMocksControl control;
+ private ClassLoader cl;
+ private ClassLoader parent;
+ private Context context;
+ private ServletContext servletContext;
+ private WebappServiceLoader<ServletContainerInitializer> loader;
+
+ @Before
+ public void init() {
+ control = EasyMock.createStrictControl();
+ parent = control.createMock(ClassLoader.class);
+ cl = EasyMock.createMockBuilder(ClassLoader.class)
+ .withConstructor(parent)
+ .addMockedMethod("loadClass", String.class)
+ .createMock(control);
+ servletContext = control.createMock(ServletContext.class);
+ EasyMock.expect(servletContext.getClassLoader()).andStubReturn(cl);
+ context = new ExtendedTesterContext(servletContext, parent);
+ }
+
+ @Test
+ public void testNoInitializersFound() throws IOException {
+ loader = new WebappServiceLoader<ServletContainerInitializer>(context);
+ EasyMock.expect(cl.getResources(CONFIG_FILE))
+ .andReturn(Collections.<URL>enumeration(Collections.<URL>emptyList()));
+ EasyMock.expect(servletContext.getAttribute(ServletContext.ORDERED_LIBS))
+ .andReturn(null);
+ EasyMock.expect(cl.getResources(CONFIG_FILE))
+ .andReturn(Collections.<URL>enumeration(Collections.<URL>emptyList()));
+ control.replay();
+ Assert.assertTrue(loader.load(ServletContainerInitializer.class).isEmpty());
+ control.verify();
+ }
+
+ @Test
+ @SuppressWarnings("unchecked")
+ public void testInitializerFromClasspath() throws IOException {
+ URL url = new URL("file://test");
+ loader = EasyMock.createMockBuilder(WebappServiceLoader.class)
+ .addMockedMethod("parseConfigFile", LinkedHashSet.class, URL.class)
+ .withConstructor(context).createMock(control);
+ EasyMock.expect(cl.getResources(CONFIG_FILE))
+ .andReturn(Collections.enumeration(Collections.singleton(url)));
+ loader.parseConfigFile(EasyMock.isA(LinkedHashSet.class), EasyMock.same(url));
+ EasyMock.expect(servletContext.getAttribute(ServletContext.ORDERED_LIBS))
+ .andReturn(null);
+ EasyMock.expect(cl.getResources(CONFIG_FILE))
+ .andReturn(Collections.enumeration(Collections.singleton(url)));
+ control.replay();
+ Assert.assertTrue(loader.load(ServletContainerInitializer.class).isEmpty());
+ control.verify();
+ }
+
+ @Test
+ @SuppressWarnings("unchecked")
+ public void testWithOrdering() throws IOException {
+ URL url1 = new URL("file://jar1.jar");
+ URL sci1 = new URL("jar:file://jar1.jar!/" + CONFIG_FILE);
+ URL url2 = new URL("file://dir/");
+ URL sci2 = new URL("file://dir/" + CONFIG_FILE);
+ loader = EasyMock.createMockBuilder(WebappServiceLoader.class)
+ .addMockedMethod("parseConfigFile", LinkedHashSet.class, URL.class)
+ .withConstructor(context).createMock(control);
+ List<String> jars = Arrays.asList("jar1.jar", "dir/");
+ EasyMock.expect(parent.getResources(CONFIG_FILE))
+ .andReturn(Collections.<URL>enumeration(Collections.<URL>emptyList()));
+ EasyMock.expect(servletContext.getAttribute(ServletContext.ORDERED_LIBS))
+ .andReturn(jars);
+ EasyMock.expect(servletContext.getResource("/WEB-INF/classes/" + CONFIG_FILE))
+ .andReturn(null);
+ EasyMock.expect(servletContext.getResource("/WEB-INF/lib/jar1.jar"))
+ .andReturn(url1);
+ loader.parseConfigFile(EasyMock.isA(LinkedHashSet.class), EasyMock.eq(sci1));
+ EasyMock.expect(servletContext.getResource("/WEB-INF/lib/dir/"))
+ .andReturn(url2);
+ loader.parseConfigFile(EasyMock.isA(LinkedHashSet.class), EasyMock.eq(sci2));
+
+ control.replay();
+ Assert.assertTrue(loader.load(ServletContainerInitializer.class).isEmpty());
+ control.verify();
+ }
+
+ @Test
+ public void testParseConfigFile() throws IOException {
+ LinkedHashSet<String> found = new LinkedHashSet<String>();
+ loader = new WebappServiceLoader<ServletContainerInitializer>(context);
+ loader.parseConfigFile(found, getClass().getResource("service-config.txt"));
+ Assert.assertEquals(Collections.singleton("provider1"), found);
+ }
+
+ @Test
+ public void testLoadServices() throws Exception {
+ Class<?> sci = TesterServletContainerInitializer1.class;
+ loader = new WebappServiceLoader<ServletContainerInitializer>(context);
+ cl.loadClass(sci.getName());
+ EasyMock.expectLastCall()
+ .andReturn(sci);
+ LinkedHashSet<String> names = new LinkedHashSet<String>();
+ names.add(sci.getName());
+ control.replay();
+ Collection<ServletContainerInitializer> initializers =
+ loader.loadServices(ServletContainerInitializer.class, names);
+ Assert.assertEquals(1, initializers.size());
+ Assert.assertTrue(sci.isInstance(initializers.iterator().next()));
+ control.verify();
+ }
+
+ @Test
+ public void testServiceIsNotExpectedType() throws Exception {
+ Class<?> sci = Object.class;
+ loader = new WebappServiceLoader<ServletContainerInitializer>(context);
+ cl.loadClass(sci.getName());
+ EasyMock.expectLastCall()
+ .andReturn(sci);
+ LinkedHashSet<String> names = new LinkedHashSet<String>();
+ names.add(sci.getName());
+ control.replay();
+ try {
+ loader.loadServices(ServletContainerInitializer.class, names);
+ } catch (IOException e) {
+ Assert.assertTrue(e.getCause() instanceof ClassCastException);
+ } finally {
+ control.verify();
+ }
+ }
-public class TestWebappServiceLoader extends TomcatBaseTest {
@Test
- public void testWebapp() throws Exception {
- Tomcat tomcat = getTomcatInstance();
- File appDir = new File("test/webapp-fragments-empty-absolute-ordering");
- StandardContext ctxt = (StandardContext) tomcat.addContext(null, "/test", appDir.getAbsolutePath());
- ctxt.addLifecycleListener(new ContextConfig());
- tomcat.start();
-
- WebappServiceLoader<ServletContainerInitializer> loader =
- new WebappServiceLoader<ServletContainerInitializer>(ctxt);
- @SuppressWarnings("unused")
- Collection<ServletContainerInitializer> initializers = loader.load(ServletContainerInitializer.class);
+ public void testServiceCannotBeConstructed() throws Exception {
+ Class<?> sci = Integer.class;
+ loader = new WebappServiceLoader<ServletContainerInitializer>(context);
+ cl.loadClass(sci.getName());
+ EasyMock.expectLastCall()
+ .andReturn(sci);
+ LinkedHashSet<String> names = new LinkedHashSet<String>();
+ names.add(sci.getName());
+ control.replay();
+ try {
+ loader.loadServices(ServletContainerInitializer.class, names);
+ } catch (IOException e) {
+ Assert.assertTrue(e.getCause() instanceof InstantiationException);
+ } finally {
+ control.verify();
+ }
+ }
+
+ private static class ExtendedTesterContext extends TesterContext {
+ private final ServletContext servletContext;
+ private final ClassLoader parent;
+
+ public ExtendedTesterContext(ServletContext servletContext, ClassLoader parent) {
+ this.servletContext = servletContext;
+ this.parent = parent;
+ }
+
+ @Override
+ public ServletContext getServletContext() {
+ return servletContext;
+ }
+
+ @Override
+ public String getContainerSciFilter() {
+ return "";
+ }
+
+ @Override
+ public ClassLoader getParentClassLoader() {
+ return parent;
+ }
}
}
diff --git a/test/org/apache/catalina/startup/service-config.txt b/test/org/apache/catalina/startup/service-config.txt
new file mode 100644
index 0000000..a2081b0
--- /dev/null
+++ b/test/org/apache/catalina/startup/service-config.txt
@@ -0,0 +1,20 @@
+# 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.
+
+# This is a test file for the WebappServiceLoader
+# It contains comment lines and blank lines
+
+provider1 # This comment should be ignored
+provider1 # provider 1 should only be returned once
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index 79e9f9f..65cb37c 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -80,6 +80,11 @@
replacement in configuration files. Based on a pull request provided by
Bernd Bohmann. (markt)
</fix>
+ <fix>
+ Rework the fix for <bug>64021</bug> to better support web applications
+ that use a custom class loader that loads resources from non-standard
+ locations. (markt)
+ </fix>
</changelog>
</subsection>
<subsection name="Coyote">
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