Author: rmannibucau
Date: Thu May 3 14:06:47 2012
New Revision: 1333464
URL: http://svn.apache.org/viewvc?rev=1333464&view=rev
Log:
geronimo ProviderLocator doesn't seem to fit very well in tomee, let's try
something else managing OSGi by reflection
Added:
openejb/trunk/javaee-api/src/main/java/javax/
openejb/trunk/javaee-api/src/main/java/javax/xml/
openejb/trunk/javaee-api/src/main/java/javax/xml/bind/
openejb/trunk/javaee-api/src/main/java/javax/xml/bind/ContextFinder.java
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/ProviderLocator.java
Modified:
openejb/trunk/javaee-api/pom.xml
Modified: openejb/trunk/javaee-api/pom.xml
URL:
http://svn.apache.org/viewvc/openejb/trunk/javaee-api/pom.xml?rev=1333464&r1=1333463&r2=1333464&view=diff
==============================================================================
--- openejb/trunk/javaee-api/pom.xml (original)
+++ openejb/trunk/javaee-api/pom.xml Thu May 3 14:06:47 2012
@@ -43,7 +43,15 @@
</resource>
</resources>
<plugins>
-
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>2.4</version>
+ <configuration>
+ <source>1.6</source>
+ <target>1.6</target>
+ </configuration>
+ </plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
@@ -104,6 +112,7 @@
<artifact>org.apache.geronimo.specs:*</artifact>
<excludes>
<exclude>META-INF/*.txt</exclude>
+ <exclude>javax/xml/bind/ContextFinder.class</exclude>
</excludes>
</filter>
<filter>
@@ -146,6 +155,7 @@
<artifact>org.apache.geronimo.specs:*</artifact>
<excludes>
<exclude>META-INF/*.txt</exclude>
+ <exclude>javax/xml/bind/ContextFinder.class</exclude>
</excludes>
</filter>
<filter>
Added: openejb/trunk/javaee-api/src/main/java/javax/xml/bind/ContextFinder.java
URL:
http://svn.apache.org/viewvc/openejb/trunk/javaee-api/src/main/java/javax/xml/bind/ContextFinder.java?rev=1333464&view=auto
==============================================================================
--- openejb/trunk/javaee-api/src/main/java/javax/xml/bind/ContextFinder.java
(added)
+++ openejb/trunk/javaee-api/src/main/java/javax/xml/bind/ContextFinder.java
Thu May 3 14:06:47 2012
@@ -0,0 +1,332 @@
+/**
+ * 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.
+ */
+package javax.xml.bind;
+
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.util.*;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+
+/**
+ * we use it to endorse tomee and we don't want to depend on OSGi as it is
done in geronimo
+ */
+class ContextFinder {
+
+ private static final String PLATFORM_DEFAULT_FACTORY_CLASS =
"com.sun.xml.bind.v2.ContextFactory";
+ private static final String JAXB_CONTEXT_PROPERTY =
JAXBContext.class.getName();
+ private static final String JAXB_CONTEXT_FACTORY =
JAXBContext.JAXB_CONTEXT_FACTORY;
+
+ private static Class<?> osgiLocator;
+ private static Method getServiceClassMethod;
+ private static Method loadClassMethod;
+
+ static {
+ try {
+ osgiLocator =
Thread.currentThread().getContextClassLoader().loadClass("org.apache.geronimo.osgi.locator.ProviderLocator");
+ getServiceClassMethod = osgiLocator.getMethod("getServiceClass",
String.class, Class.class, ClassLoader.class);
+ loadClassMethod = osgiLocator.getMethod("loadClass", String.class,
Class.class, ClassLoader.class);
+ } catch (ClassNotFoundException e) {
+ osgiLocator = null;
+ } catch (NoSuchMethodException e) {
+ osgiLocator = null;
+ }
+ }
+
+ public static JAXBContext find(String contextPath, ClassLoader
classLoader, Map properties) throws JAXBException {
+ contextPath = contextPath.trim();
+ if (contextPath.length() == 0 || contextPath.equals(":")) {
+ throw new JAXBException("Invalid contextPath");
+ }
+ String className = null;
+ String[] packages = contextPath.split("[:]");
+ for (String pkg : packages) {
+ String url = pkg.replace('.', '/') + "/jaxb.properties";
+ className = loadClassNameFromProperties(url, classLoader);
+ if (className != null) {
+ break;
+ }
+ }
+ if (className == null) {
+ className = System.getProperty(JAXB_CONTEXT_PROPERTY);
+ }
+ Class spi = null;
+ // if no specifically specified name, check for META-INF/services, and
+ // fall back to the default factory class if that fails
+ if (className == null) {
+ spi = loadSPIClass(JAXBContext.class, classLoader);
+ if (spi == null) {
+ spi = loadSpi(PLATFORM_DEFAULT_FACTORY_CLASS, classLoader);
+ }
+ }
+ else {
+ spi = loadSpi(className, classLoader);
+ }
+ try {
+ Method m = spi.getMethod("createContext", new Class[] {
String.class, ClassLoader.class, Map.class });
+ return (JAXBContext) m.invoke(null, new Object[] { contextPath,
classLoader, properties });
+ } catch (NoSuchMethodException e) {
+ // will try JAXB 1.0 compatible createContext() method
+ } catch (Throwable t) {
+ throw new JAXBException("Unable to create context", t);
+ }
+
+ // try old JAXB 1.0 compatible createContext() method
+ try {
+ Method m = spi.getMethod("createContext", new Class[] {
String.class, ClassLoader.class });
+ return (JAXBContext) m.invoke(null, new Object[] { contextPath,
classLoader });
+ } catch (Throwable t) {
+ throw new JAXBException("Unable to create context", t);
+ }
+ }
+
+
+ public static JAXBContext find(Class[] classes, Map properties) throws
JAXBException {
+ String className = null;
+ for (Class cl : classes) {
+ Package pkg = cl.getPackage();
+ if (pkg != null) {
+ String url = pkg.getName().replace('.', '/') +
"/jaxb.properties";
+ className = loadClassNameFromProperties(url,
cl.getClassLoader());
+ if (className != null) {
+ break;
+ }
+ }
+ }
+ if (className == null) {
+ className = System.getProperty(JAXB_CONTEXT_PROPERTY);
+ }
+ ClassLoader classLoader =
Thread.currentThread().getContextClassLoader();
+
+ Class spi = null;
+ // if no specifically specified name, check for META-INF/services, and
+ // fall back to the default factory class if that fails
+ if (className == null) {
+ spi = loadSPIClass(JAXBContext.class, classLoader);
+ if (spi == null) {
+ spi = loadSpi(PLATFORM_DEFAULT_FACTORY_CLASS, classLoader);
+ }
+ }
+ else {
+ spi = loadSpi(className, classLoader);
+ }
+ try {
+ Method m = spi.getMethod("createContext", new Class[] {
Class[].class, Map.class });
+ return (JAXBContext) m.invoke(null, new Object[] { classes,
properties });
+ } catch (Throwable t) {
+ throw new JAXBException("Unable to create context", t);
+ }
+ }
+
+ private static String loadClassNameFromProperties(String url, ClassLoader
classLoader) throws JAXBException {
+ try {
+ InputStream is;
+ if (classLoader != null) {
+ is = classLoader.getResourceAsStream(url);
+ } else {
+ is = ClassLoader.getSystemResourceAsStream(url);
+ }
+ if (is != null) {
+ try {
+ Properties props = new Properties();
+ props.load(is);
+ String className = props.getProperty(JAXB_CONTEXT_FACTORY);
+ if (className == null) {
+ throw new JAXBException("jaxb.properties file " + url
+ " should contain a " + JAXB_CONTEXT_FACTORY + " property");
+ }
+ return className.trim();
+ } finally {
+ is.close();
+ }
+ } else {
+ return null;
+ }
+ } catch (IOException e) {
+ throw new JAXBException(e);
+ }
+ }
+
+ private static Class<?> loadSPIClass(Class<?> iface, ClassLoader
classLoader) throws JAXBException {
+ if (osgiLocator != null) {
+ return loadSPIClassFromOSGi(iface, classLoader);
+ }
+
+ try {
+ return locateServiceClass(iface.getName(), ContextFinder.class,
classLoader);
+ } catch (ClassNotFoundException e) {
+ throw new JAXBException("Provider " + iface.getName() + " not
found", e);
+ }
+ }
+
+ static private Class<?> locateServiceClass(String iface, Class<?>
contextClass, ClassLoader loader) throws ClassNotFoundException {
+ String className = locateServiceClassName(iface, contextClass, loader);
+ if (className == null) {
+ return null;
+ }
+
+ // we found a name, try loading the class. This will throw an
exception if there is an error
+ return loadClass(className, contextClass, loader);
+ }
+
+ static private String locateServiceClassName(String iface, Class<?>
contextClass, ClassLoader loader) {
+ // search first with the loader class path
+ String name = locateServiceClassName(iface, loader);
+ if (name != null) {
+ return name;
+ }
+ // then with the context class, if there is one
+ if (contextClass != null) {
+ name = locateServiceClassName(iface,
contextClass.getClassLoader());
+ if (name != null) {
+ return name;
+ }
+ }
+ // not found
+ return null;
+ }
+
+ static private String locateServiceClassName(String iface, ClassLoader
loader) {
+ if (loader != null) {
+ try {
+ // we only look at resources that match the file name, using
the specified loader
+ String service = "META-INF/services/" + iface;
+ Enumeration<URL> providers = loader.getResources(service);
+
+ while (providers.hasMoreElements()) {
+ List<String>providerNames =
parseServiceDefinition(providers.nextElement());
+ // if there is something defined here, return the first
entry
+ if (!providerNames.isEmpty()) {
+ return providerNames.get(0);
+ }
+ }
+ } catch (IOException e) {
+ }
+ }
+ // not found
+ return null;
+ }
+
+ static public Class<?> loadClass(String className, Class<?> contextClass,
ClassLoader loader) throws ClassNotFoundException {
+ if (loader != null) {
+ try {
+ return loader.loadClass(className);
+ } catch (ClassNotFoundException x) {
+ }
+ }
+ if (contextClass != null) {
+ loader = contextClass.getClassLoader();
+ }
+ // try again using the class context loader
+ return Class.forName(className, true, loader);
+ }
+
+ static private Collection<String> locateServiceClassNames(String iface,
Class<?> contextClass, ClassLoader loader) {
+ Set<String> names = new LinkedHashSet<String>();
+
+ locateServiceClassNames(iface, loader, names);
+ if (contextClass != null) {
+ locateServiceClassNames(iface, contextClass.getClassLoader(),
names);
+ }
+
+ return names;
+ }
+
+ static void locateServiceClassNames(String iface, ClassLoader loader, Set
names) {
+ if (loader != null) {
+
+ try {
+ // we only look at resources that match the file name, using
the specified loader
+ String service = "META-INF/services/" + iface;
+ Enumeration<URL> providers = loader.getResources(service);
+
+ while (providers.hasMoreElements()) {
+ List<String>providerNames =
parseServiceDefinition(providers.nextElement());
+ // just add all of these to the list
+ names.addAll(providerNames);
+ }
+ } catch (IOException e) {
+ }
+ }
+ }
+
+ static private List<String> parseServiceDefinition(URL u) {
+ final String url = u.toString();
+ List<String> classes = new ArrayList<String>();
+ // ignore directories
+ if (url.endsWith("/")) {
+ return classes;
+ }
+ // the identifier used for the provider is the last item in the URL.
+ final String providerId = url.substring(url.lastIndexOf("/") + 1);
+ try {
+ BufferedReader br = new BufferedReader(new
InputStreamReader(u.openStream(), "UTF-8"));
+ // the file can be multiple lines long, with comments. A single
file can define multiple providers
+ // for a single key, so we might need to create multiple entries.
If the file does not contain any
+ // definition lines, then as a default, we use the providerId as
an implementation class also.
+ String line = br.readLine();
+ while (line != null) {
+ // we allow comments on these lines, and a line can be all
comment
+ int comment = line.indexOf('#');
+ if (comment != -1) {
+ line = line.substring(0, comment);
+ }
+ line = line.trim();
+ // if there is nothing left on the line after stripping white
space and comments, skip this
+ if (line.length() > 0) {
+ // add this to our list
+ classes.add(line);
+ }
+ // keep reading until the end.
+ line = br.readLine();
+ }
+ br.close();
+ } catch (IOException e) {
+ // ignore errors and handle as default
+ }
+ return classes;
+ }
+
+ private static Class loadSpi(String className, ClassLoader classLoader)
throws JAXBException {
+ if (osgiLocator != null) {
+ return loadSpiFromOSGi(className, classLoader);
+ }
+
+ try {
+ return loadClass(className, ContextFinder.class, classLoader);
+ } catch (ClassNotFoundException e) {
+ throw new JAXBException("Provider " + className + " not found", e);
+ }
+ }
+
+ private static Class<?> loadSPIClassFromOSGi(Class<?> iface, ClassLoader
classLoader) throws JAXBException {
+ try {
+ return (Class<?>) getServiceClassMethod.invoke(null,
iface.getName(), ContextFinder.class,classLoader);
+ } catch (Exception e) {
+ return null;
+ }
+ }
+
+ private static Class loadSpiFromOSGi(String className, ClassLoader
classLoader) throws JAXBException {
+ try {
+ return (Class<?>) loadClassMethod.invoke(null, className,
ContextFinder.class, classLoader);
+ } catch (Exception e) {
+ throw new JAXBException("Provider " + className + " not found", e);
+ }
+ }
+}
Added:
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/ProviderLocator.java
URL:
http://svn.apache.org/viewvc/openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/ProviderLocator.java?rev=1333464&view=auto
==============================================================================
---
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/ProviderLocator.java
(added)
+++
openejb/trunk/javaee-api/src/main/java/org/apache/openejb/javaee/api/activator/org/apache/openejb/javaee/api/locator/ProviderLocator.java
Thu May 3 14:06:47 2012
@@ -0,0 +1,463 @@
+/**
+ * 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.
+ */
+package
org.apache.openejb.javaee.api.activator.org.apache.openejb.javaee.api.locator;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Properties;
+import java.util.Set;
+
+public class ProviderLocator {
+ // our bundle context
+ static private Object context;
+ // a service tracker for the registry service
+ // NB: This is declared as just Object to avoid classloading issues if
we're running
+ // outside of an OSGi environment.
+ static private Object registryTracker;
+
+ private static Class<?> bundleContextClazz = null;
+ private static Class<?> serviceTrackerClazz = null;
+
+ static {
+ final ClassLoader cl = Thread.currentThread().getContextClassLoader();
+ try {
+ bundleContextClazz =
cl.loadClass("org.osgi.framework.BundleContext");
+ serviceTrackerClazz =
cl.loadClass("org.osgi.util.tracker.ServiceTracker");
+ } catch (ClassNotFoundException e) {
+ e.printStackTrace(); //To change body of catch statement use File
| Settings | File Templates.
+ }
+ }
+
+ private ProviderLocator() {
+ // private constructor to prevent an instance from getting created.
+ }
+
+ /**
+ * Utility class for locating a class with OSGi registry
+ * support. Uses the thread context classloader as part of
+ * the search order.
+ *
+ * @param className The name of the target class.
+ *
+ * @return The loaded class.
+ * @exception ClassNotFoundException
+ * Thrown if the class cannot be located.
+ */
+ static public Class<?> loadClass(String className) throws
ClassNotFoundException {
+ return loadClass(className, null,
Thread.currentThread().getContextClassLoader());
+ }
+
+ /**
+ * Utility class for locating a class with OSGi registry
+ * support. Uses the thread context classloader as part of
+ * the search order.
+ *
+ * @param className The name of the target class.
+ *
+ * @return The loaded class.
+ * @exception ClassNotFoundException
+ * Thrown if the class cannot be located.
+ */
+ static public Class<?> loadClass(String className, Class<?> contextClass)
throws ClassNotFoundException {
+ return loadClass(className, contextClass,
Thread.currentThread().getContextClassLoader());
+ }
+
+ /**
+ * Standardized utility method for performing class lookups
+ * with support for OSGi registry lookups.
+ *
+ * @param className The name of the target class.
+ * @param loader An optional class loader.
+ *
+ * @return The loaded class
+ * @exception ClassNotFoundException
+ * Thrown if the class cannot be loaded.
+ */
+ static public Class<?> loadClass(String className, Class<?>contextClass,
ClassLoader loader) throws ClassNotFoundException {
+ if (loader != null) {
+ try {
+ return loader.loadClass(className);
+ } catch (ClassNotFoundException x) {
+ }
+ }
+ if (contextClass != null) {
+ loader = contextClass.getClassLoader();
+ }
+ // try again using the class context loader
+ return Class.forName(className, true, loader);
+ }
+
+
+ /**
+ * Get a single service instance that matches an interface
+ * definition.
+ *
+ * @param iface The name of the required interface.
+ * @param contextClass
+ * The class requesting the lookup (used for class
resolution).
+ * @param loader A class loader to use for searching for service
definitions
+ * and loading classes.
+ *
+ * @return The service instance, or null if no matching services
+ * can be found.
+ * @exception Exception Thrown for any classloading or exceptions thrown
+ * trying to instantiate a service instance.
+ */
+ static public Object getService(String iface, Class<?> contextClass,
ClassLoader loader) throws Exception {
+ // try for a classpath locatable instance next. If we find an
appropriate class mapping,
+ // create an instance and return it.
+ Class<?> cls = locateServiceClass(iface, contextClass, loader);
+ if (cls != null) {
+ return cls.newInstance();
+ }
+ // a provider was not found
+ return null;
+ }
+
+
+ /**
+ * Locate a service class that matches an interface
+ * definition.
+ *
+ * @param iface The name of the required interface.
+ * @param contextClass
+ * The class requesting the lookup (used for class
resolution).
+ * @param loader A class loader to use for searching for service
definitions
+ * and loading classes.
+ *
+ * @return The located class, or null if no matching services
+ * can be found.
+ * @exception Exception Thrown for any classloading exceptions thrown
+ * trying to load the class.
+ */
+ static public Class<?> getServiceClass(String iface, Class<?>
contextClass, ClassLoader loader) throws ClassNotFoundException {
+ return locateServiceClass(iface, contextClass, loader);
+ }
+
+
+ /**
+ * Get a list of services that match a given interface
+ * name. This searches both the current class path and
+ * the global repository for matches.
+ *
+ * @param iface The name of the required interface.
+ * @param contextClass
+ * The class requesting the lookup (used for class
resolution).
+ * @param loader A class loader to use for searching for service
definitions
+ * and loading classes.
+ *
+ * @return A list of matching services. Returns an empty list if there
+ * are no matches.
+ * @exception Exception Thrown for any classloading or exceptions thrown
+ * trying to instantiate a service instance.
+ */
+ static public List<Object> getServices(String iface, Class<?>
contextClass, ClassLoader loader) throws Exception {
+ List<Object> services = new ArrayList<Object>();
+
+ // try for a classpath locatable instance second. If we find an
appropriate class mapping,
+ // create an instance and return it.
+ Collection<Class<?>> classes = locateServiceClasses(iface,
contextClass, loader);
+ if (classes != null) {
+ // create an instance of each of these classes
+ for (Class<?> cls : classes) {
+ services.add(cls.newInstance());
+ }
+ }
+
+ // now return the merged set
+ return services;
+ }
+
+
+ /**
+ * Get a list of service class implementations that match
+ * an interface name. This searches both the current class path and
+ * the global repository for matches.
+ *
+ * @param iface The name of the required interface.
+ * @param contextClass
+ * The class requesting the lookup (used for class
resolution).
+ * @param loader A class loader to use for searching for service
definitions
+ * and loading classes.
+ *
+ * @return A list of matching provider classes. Returns an empty list if
there
+ * are no matches.
+ * @exception Exception Thrown for any classloading exceptions thrown
+ * trying to load a provider class.
+ */
+ static public List<Class<?>> getServiceClasses(String iface, Class<?>
contextClass, ClassLoader loader) throws Exception {
+ Set<Class<?>> serviceClasses = new LinkedHashSet<Class<?>>();
+
+ // try for a classpath locatable classes second. If we find an
appropriate class mapping,
+ // add this to our return collection.
+ Collection<Class<?>> classes = locateServiceClasses(iface,
contextClass, loader);
+ if (classes != null) {
+ serviceClasses.addAll(classes);
+ }
+ // now return the merged set
+ return new ArrayList(serviceClasses);
+ }
+
+
+ /**
+ * Locate the first class name for a META-INF/services definition
+ * of a given class. The first matching provider is
+ * returned.
+ *
+ * @param iface The interface class name used for the match.
+ * @param loader The classloader for locating resources.
+ *
+ * @return The mapped provider name, if found. Returns null if
+ * no mapping is located.
+ */
+ static private String locateServiceClassName(String iface, Class<?>
contextClass, ClassLoader loader) {
+ // search first with the loader class path
+ String name = locateServiceClassName(iface, loader);
+ if (name != null) {
+ return name;
+ }
+ // then with the context class, if there is one
+ if (contextClass != null) {
+ name = locateServiceClassName(iface,
contextClass.getClassLoader());
+ if (name != null) {
+ return name;
+ }
+ }
+ // not found
+ return null;
+ }
+
+
+ /**
+ * Locate a classpath-define service mapping.
+ *
+ * @param iface The required interface name.
+ * @param loader The ClassLoader instance to use to locate the service.
+ *
+ * @return The mapped class name, if one is found. Returns null if the
+ * mapping is not located.
+ */
+ static private String locateServiceClassName(String iface, ClassLoader
loader) {
+ if (loader != null) {
+ try {
+ // we only look at resources that match the file name, using
the specified loader
+ String service = "META-INF/services/" + iface;
+ Enumeration<URL> providers = loader.getResources(service);
+
+ while (providers.hasMoreElements()) {
+ List<String>providerNames =
parseServiceDefinition(providers.nextElement());
+ // if there is something defined here, return the first
entry
+ if (!providerNames.isEmpty()) {
+ return providerNames.get(0);
+ }
+ }
+ } catch (IOException e) {
+ }
+ }
+ // not found
+ return null;
+ }
+
+
+ /**
+ * Locate the first class for a META-INF/services definition
+ * of a given interface class. The first matching provider is
+ * returned.
+ *
+ * @param iface The interface class name used for the match.
+ * @param loader The classloader for locating resources.
+ *
+ * @return The mapped provider class, if found. Returns null if
+ * no mapping is located.
+ */
+ static private Class<?> locateServiceClass(String iface, Class<?>
contextClass, ClassLoader loader) throws ClassNotFoundException {
+ String className = locateServiceClassName(iface, contextClass, loader);
+ if (className == null) {
+ return null;
+ }
+
+ // we found a name, try loading the class. This will throw an
exception if there is an error
+ return loadClass(className, contextClass, loader);
+ }
+
+
+ /**
+ * Locate all class names name for a META-INF/services definition
+ * of a given class.
+ *
+ * @param iface The interface class name used for the match.
+ * @param loader The classloader for locating resources.
+ *
+ * @return The mapped provider name, if found. Returns null if
+ * no mapping is located.
+ */
+ static private Collection<String> locateServiceClassNames(String iface,
Class<?> contextClass, ClassLoader loader) {
+ Set<String> names = new LinkedHashSet<String>();
+
+ locateServiceClassNames(iface, loader, names);
+ if (contextClass != null) {
+ locateServiceClassNames(iface, contextClass.getClassLoader(),
names);
+ }
+
+ return names;
+ }
+
+
+ /**
+ * Locate all class names name for a META-INF/services definition
+ * of a given class.
+ *
+ * @param iface The interface class name used for the match.
+ * @param loader The classloader for locating resources.
+ *
+ * @return The mapped provider name, if found. Returns null if
+ * no mapping is located.
+ */
+ static void locateServiceClassNames(String iface, ClassLoader loader, Set
names) {
+ if (loader != null) {
+
+ try {
+ // we only look at resources that match the file name, using
the specified loader
+ String service = "META-INF/services/" + iface;
+ Enumeration<URL> providers = loader.getResources(service);
+
+ while (providers.hasMoreElements()) {
+ List<String>providerNames =
parseServiceDefinition(providers.nextElement());
+ // just add all of these to the list
+ names.addAll(providerNames);
+ }
+ } catch (IOException e) {
+ }
+ }
+ }
+
+
+ /**
+ * Locate all classes that map to a given provider class definition. This
will
+ * search both the services directories, as well as the provider classes
from the
+ * OSGi provider registry.
+ *
+ * @param iface The interface class name used for the match.
+ * @param loader The classloader for locating resources.
+ *
+ * @return A list of all mapped classes, if found. Returns an empty list
if
+ * no mappings are found.
+ */
+ static private Collection<Class<?>> locateServiceClasses(String iface,
Class<?> contextClass, ClassLoader loader) throws ClassNotFoundException {
+ // get the set of names from services definitions on the classpath
+ Collection<String> classNames = locateServiceClassNames(iface,
contextClass, loader);
+ Set<Class<?>> classes = new LinkedHashSet<Class<?>>();
+
+ // load each class and add to our return set
+ for (String name : classNames) {
+ classes.add(loadClass(name, contextClass, loader));
+ }
+ return classes;
+ }
+
+
+ /**
+ * Parse a definition file and return the names of all included
implementation classes
+ * contained within the file.
+ *
+ * @param u The URL of the file
+ *
+ * @return A list of all matching classes. Returns an empty list
+ * if no matches are found.
+ */
+ static private List<String> parseServiceDefinition(URL u) {
+ final String url = u.toString();
+ List<String> classes = new ArrayList<String>();
+ // ignore directories
+ if (url.endsWith("/")) {
+ return classes;
+ }
+ // the identifier used for the provider is the last item in the URL.
+ final String providerId = url.substring(url.lastIndexOf("/") + 1);
+ try {
+ BufferedReader br = new BufferedReader(new
InputStreamReader(u.openStream(), "UTF-8"));
+ // the file can be multiple lines long, with comments. A single
file can define multiple providers
+ // for a single key, so we might need to create multiple entries.
If the file does not contain any
+ // definition lines, then as a default, we use the providerId as
an implementation class also.
+ String line = br.readLine();
+ while (line != null) {
+ // we allow comments on these lines, and a line can be all
comment
+ int comment = line.indexOf('#');
+ if (comment != -1) {
+ line = line.substring(0, comment);
+ }
+ line = line.trim();
+ // if there is nothing left on the line after stripping white
space and comments, skip this
+ if (line.length() > 0) {
+ // add this to our list
+ classes.add(line);
+ }
+ // keep reading until the end.
+ line = br.readLine();
+ }
+ br.close();
+ } catch (IOException e) {
+ // ignore errors and handle as default
+ }
+ return classes;
+ }
+
+ /**
+ * Perform a service class discovery by looking for a
+ * property in a target properties file located in the
+ * java.home directory.
+ *
+ * @param path The relative path to the desired properties file.
+ * @param property The name of the required property.
+ *
+ * @return The value of the named property within the properties file.
Returns
+ * null if the property doesn't exist or the properties file
doesn't exist.
+ */
+ public static String lookupByJREPropertyFile(String path, String property)
throws IOException {
+ String jreDirectory = System.getProperty("java.home");
+ File configurationFile = new File(jreDirectory + File.separator +
path);
+ if (configurationFile.exists() && configurationFile.canRead()) {
+ Properties properties = new Properties();
+ InputStream in = null;
+ try {
+ in = new FileInputStream(configurationFile);
+ properties.load(in);
+ return properties.getProperty(property);
+ } finally {
+ if (in != null) {
+ try {
+ in.close();
+ } catch (Exception e) {
+ }
+ }
+ }
+ }
+ return null;
+ }
+}
