Make the ServiceDiscovery pluggable and add support for OSGi-based service discoverer

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@675040 13f79535-47bb-0310-9956-ffa450edef68

5 files changed, 427 insertions, 296 deletions

diff --git a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscover.java b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscover.java
new file mode 100644
index 0000000000..c83a7d9172
--- /dev/null
+++ b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscover.java
@@ -0,0 +1,237 @@
+/*
+ * 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.tuscany.sca.extensibility;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.lang.ref.WeakReference;
+import java.net.URL;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.StringTokenizer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * 
+ */
+public class ClasspathServiceDiscover implements ServiceDiscoverer {
+
+    public class ServiceDeclarationImpl implements ServiceDeclaration {
+        private URL url;
+        private String className;
+        private Class<?> javaClass;
+        private Map<String, String> attributes;
+
+        public ServiceDeclarationImpl(URL url, String className, Map<String, String> attributes) {
+            super();
+            this.url = url;
+            this.className = className;
+            this.attributes = attributes;
+        }
+
+        public Map<String, String> getAttributes() {
+            return attributes;
+        }
+
+        public String getClassName() {
+            return className;
+        }
+
+        public URL getLocation() {
+            return url;
+        }
+
+        public Class<?> loadClass() throws ClassNotFoundException {
+            if (className == null) {
+                return null;
+            }
+            if (javaClass == null) {
+                javaClass = loadClass(className);
+            }
+            return javaClass;
+        }
+
+        public Class<?> loadClass(String className) throws ClassNotFoundException {
+            return getClassLoader().loadClass(className);
+        }
+
+        private ClasspathServiceDiscover getOuterType() {
+            return ClasspathServiceDiscover.this;
+        }
+
+        public String toString() {
+            StringBuffer sb = new StringBuffer();
+            sb.append("ClassLoader: ").append(getClassLoader());
+            sb.append(" Attributes: ").append(attributes);
+            return sb.toString();
+        }
+
+        public URL getResource(final String name) {
+            return AccessController.doPrivileged(new PrivilegedAction<URL>() {
+                public URL run() {
+                    return getClassLoader().getResource(name);
+                }
+            });
+        }
+
+    }
+
+    private WeakReference<ClassLoader> classLoaderReference;
+    private static final Logger logger = Logger.getLogger(ClasspathServiceDiscover.class.getName());
+
+    public ClasspathServiceDiscover() {
+        // ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+        ClassLoader classLoader = ClasspathServiceDiscover.class.getClassLoader();
+        this.classLoaderReference = new WeakReference<ClassLoader>(classLoader);
+    }
+
+    public ClasspathServiceDiscover(ClassLoader classLoader) {
+        this.classLoaderReference = new WeakReference<ClassLoader>(classLoader);
+    }
+
+    protected List<URL> getResources(final String name) throws IOException {
+        try {
+            return AccessController.doPrivileged(new PrivilegedExceptionAction<List<URL>>() {
+                public List<URL> run() throws IOException {
+                    return Collections.list(getClassLoader().getResources(name));
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (IOException)e.getException();
+        }
+    }
+
+    private ClassLoader getClassLoader() {
+        return classLoaderReference.get();
+    }
+
+    /**
+     * Parse a service declaration in the form class;attr=value,attr=value and
+     * return a map of attributes
+     * 
+     * @param declaration
+     * @return a map of attributes
+     */
+    protected static Map<String, String> parseServiceDeclaration(String declaration) {
+        Map<String, String> attributes = new HashMap<String, String>();
+        int index = declaration.indexOf(';');
+        if (index != -1) {
+            attributes.put("class", declaration.substring(0, index).trim());
+            declaration = declaration.substring(index);
+        } else {
+            int j = declaration.indexOf('=');
+            if (j == -1) {
+                attributes.put("class", declaration.trim());
+                return attributes;
+            } else {
+                declaration = ";" + declaration;
+            }
+        }
+        StringTokenizer tokens = new StringTokenizer(declaration);
+        for (; tokens.hasMoreTokens();) {
+            String key = tokens.nextToken("=").substring(1).trim();
+            if (key == null)
+                break;
+            String value = tokens.nextToken(",").substring(1).trim();
+            if (value == null)
+                break;
+            attributes.put(key, value);
+        }
+        return attributes;
+    }
+
+    public Set<ServiceDeclaration> discover(String serviceName) {
+        Set<ServiceDeclaration> descriptors = new HashSet<ServiceDeclaration>();
+
+        String name = "META-INF/services/" + serviceName;
+        boolean debug = logger.isLoggable(Level.FINE);
+        try {
+            for (final URL url : getResources(name)) {
+                if (debug) {
+                    logger.fine("Reading service provider file: " + url.toExternalForm());
+                }
+
+                // Allow privileged access to open URL stream. Add FilePermission to added to security
+                // policy file.
+                InputStream is;
+                try {
+                    is = AccessController.doPrivileged(new PrivilegedExceptionAction<InputStream>() {
+                        public InputStream run() throws IOException {
+                            return url.openStream();
+                        }
+                    });
+                } catch (PrivilegedActionException e) {
+                    throw (IOException)e.getException();
+                }
+                BufferedReader reader = null;
+                try {
+                    reader = new BufferedReader(new InputStreamReader(is));
+                    int count = 0;
+                    while (true) {
+                        String line = reader.readLine();
+                        if (line == null)
+                            break;
+                        line = line.trim();
+                        if (!line.startsWith("#") && !"".equals(line)) {
+                            String reg = line.trim();
+                            if (debug) {
+                                logger.fine("Registering service provider: " + reg);
+                            }
+
+                            Map<String, String> attributes = parseServiceDeclaration(reg);
+                            String className = attributes.get("class");
+                            if (className == null) {
+                                // Add a unique class name to prevent equals() from returning true
+                                className = "_class_" + count;
+                                count++;
+                            }
+                            ServiceDeclarationImpl descriptor = new ServiceDeclarationImpl(url, className, attributes);
+                            descriptors.add(descriptor);
+                        }
+                    }
+                } finally {
+                    if (reader != null) {
+                        try {
+                            reader.close();
+                        } catch (IOException e) {
+                            // Ignore
+                        }
+                    }
+                }
+            }
+        } catch (IOException e) {
+            logger.log(Level.SEVERE, e.getMessage(), e);
+        }
+        return descriptors;
+
+    }
+
+}
diff --git a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java
index 4b25f2adc2..403b6aa7a7 100644
--- a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java
+++ b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java
@@ -19,7 +19,6 @@
 
 package org.apache.tuscany.sca.extensibility;
 
-import java.lang.ref.WeakReference;
 import java.net.URL;
 import java.util.Map;
 
@@ -30,107 +29,40 @@ import java.util.Map;
  *
  * @version $Rev$ $Date$
  */
-public class ServiceDeclaration {
-
-    private WeakReference<ClassLoader> classLoader;
-
-    private String className;
-
-    private Map<String, String> attributes;
-
-    /**
-     * Service declaration constructor
-     * 
-     * @param className Service implementation class name
-     * @param classLoader ClassLoader corresponding to this service
-     *                implementation
-     * @param attributes Optional attributes for this service declaration
-     */
-    public ServiceDeclaration(String className, ClassLoader classLoader, Map<String, String> attributes) {
-
-        this.className = className;
-        this.classLoader = new WeakReference<ClassLoader>(classLoader);
-        this.attributes = attributes;
-    }
-
+public interface ServiceDeclaration {
     /**
-     * Load this service implementation class
-     * 
-     * @return Class
+     * Load a java class in the same context as the service definition
+     * @param className The class name
+     * @return The loaded class
      * @throws ClassNotFoundException
      */
-    @SuppressWarnings("unchecked")
-    public Class<?> loadClass() throws ClassNotFoundException {
-
-        return Class.forName(className, true, classLoader.get());
-    }
-
+    Class<?> loadClass(String className) throws ClassNotFoundException;
     /**
-     * Load another class using the ClassLoader of this service implementation
-     * 
-     * @param anotherClassName
-     * @return Class
-     * @throws ClassNotFoundException
+     * Get the java class for the service impl
+     * @return The java class
      */
-    public Class<?> loadClass(String anotherClassName) throws ClassNotFoundException {
-
-        return Class.forName(anotherClassName, true, classLoader.get());
-    }
-
-    /**
-     * Return the resource corresponding to this service implementation class
-     * 
-     * @return resource URL
-     */
-    public URL getResource() {
-        return classLoader.get().getResource(className);
-    }
-
+    Class<?> loadClass() throws ClassNotFoundException;
     /**
-     * ClassLoader associated with this service declaration
-     * 
-     * @return ClassLoader
+     * Get all attributes (name=value pairs) defined for the given entry
+     * @return All attributes keyed by name
      */
-    public ClassLoader getClassLoader() {
-        return classLoader.get();
-    }
-
+    Map<String, String> getAttributes();
+    
+    URL getLocation();
+    
+    String getClassName();
+    
+    URL getResource(String name);
+    
     /**
-     * Service implementation class corresponding to this declaration
-     * 
-     * @return The Service implementation class corresponding to this declaration 
+     * The service descriptor might be hashed
+     * @param obj Another object
+     * @return
      */
-    public String getClassName() {
-        return className;
-    }
-
+    boolean equals(Object obj);
     /**
-     * Attributes specified for this declaration
-     * 
-     * @return attributes
+     * The service descriptor might be hashed
+     * @return
      */
-    public Map<String, String> getAttributes() {
-        return attributes;
-    }
-
-    /**
-     * Equals method used to ensure that each service declaration is stored only
-     * once in a set of declarations.
-     */
-    @Override
-    public boolean equals(Object o) {
-        if (!(o instanceof ServiceDeclaration))
-            return false;
-        ServiceDeclaration s = (ServiceDeclaration)o;
-        if (!className.equals(s.className))
-            return false;
-        else if (!classLoader.equals(s.classLoader))
-            return false;
-        else if (attributes == null)
-            return s.attributes == null;
-        else
-            return attributes.equals(s.attributes);
-
-    }
-
+    int hashCode();
 }
diff --git a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java
new file mode 100644
index 0000000000..31f2cf600e
--- /dev/null
+++ b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java
@@ -0,0 +1,34 @@
+/*
+ * 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.tuscany.sca.extensibility;
+
+import java.util.Set;
+
+/**
+ * 
+ */
+public interface ServiceDiscoverer {
+    /**
+     * Discover the service descriptors by name
+     * @param serviceName
+     * @return A set of service descriptors
+     */
+    Set<ServiceDeclaration> discover(String serviceName);
+}
diff --git a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java
index 45a4494f24..412774c83b 100644
--- a/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java
+++ b/java/sca/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java
@@ -19,23 +19,9 @@
 
 package org.apache.tuscany.sca.extensibility;
 
-import java.io.BufferedReader;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.net.URL;
-import java.security.AccessController;
-import java.security.PrivilegedActionException;
-import java.security.PrivilegedExceptionAction;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Hashtable;
-import java.util.Map;
 import java.util.Set;
-import java.util.StringTokenizer;
-import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
@@ -50,9 +36,10 @@ import java.util.logging.Logger;
 public class ServiceDiscovery {
     private static final Logger logger = Logger.getLogger(ServiceDiscovery.class.getName());
 
-    private static ServiceDiscovery instance;
+    private final static ServiceDiscovery instance = new ServiceDiscovery();
 
-    private HashSet<ClassLoader> registeredClassLoaders;
+    private static ServiceDiscoverer discoverer;
+    private Set<ClassLoader> registeredClassLoaders = new HashSet<ClassLoader>();
 
     /**
      * Get an instance of Service discovery, one instance is created per
@@ -61,15 +48,29 @@ public class ServiceDiscovery {
      * @return
      */
     public static ServiceDiscovery getInstance() {
-
-        if (instance == null) {
-            instance = new ServiceDiscovery();
-            instance.registeredClassLoaders = new HashSet<ClassLoader>();
-            instance.registeredClassLoaders.add(ServiceDiscovery.class.getClassLoader());
-        }
+//
+//        if (instance == null) {
+//            instance = new ServiceDiscovery();
+//            instance.registeredClassLoaders = new HashSet<ClassLoader>();
+//            instance.registeredClassLoaders.add(ServiceDiscovery.class.getClassLoader());
+//        }
         return instance;
     }
-
+    
+    public static ServiceDiscoverer getServiceDiscoverer() {
+        if (discoverer == null) {
+            discoverer = new ClasspathServiceDiscover();
+        }
+        return discoverer;
+    }
+    
+    public static void setServiceDiscoverer(ServiceDiscoverer sd) {
+        if (discoverer != null) {
+            throw new IllegalStateException("The ServiceDiscoverer cannot be reset");
+        }
+        discoverer = sd;
+    }
+    
     /**
      * Register a ClassLoader with this discovery mechanism. Tuscany extension
      * ClassLoaders are registered here.
@@ -96,14 +97,10 @@ public class ServiceDiscovery {
      * @return set of service declarations
      * @throws IOException
      */
-    public synchronized Set<ServiceDeclaration> getServiceDeclarations(String name) throws IOException {
-
-        Set<ServiceDeclaration> classSet = new HashSet<ServiceDeclaration>();
-
-        for (ClassLoader classLoader : registeredClassLoaders) {
-            getServiceClasses(classLoader, name, classSet, true);
-        }
-        return classSet;
+    public Set<ServiceDeclaration> getServiceDeclarations(String name) throws IOException {
+        // Set<ServiceDeclaration> classSet = new HashSet<ServiceDeclaration>();
+        Set<ServiceDeclaration> services = getServiceDiscoverer().discover(name);
+        return services;
     }
 
     /**
@@ -126,185 +123,55 @@ public class ServiceDiscovery {
      * @throws IOException
      * @throws ClassNotFoundException
      */
-    public synchronized Class<?> loadFirstServiceClass(Class<?> serviceInterface) throws IOException, ClassNotFoundException {
+    public Class<?> loadFirstServiceClass(Class<?> serviceInterface) throws IOException, ClassNotFoundException {
+        Set<ServiceDeclaration> services = getServiceDiscoverer().discover(serviceInterface.getName());
+        if(services.isEmpty()) {
+            return null;
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
-        Set<ServiceDeclaration> classSet = new HashSet<ServiceDeclaration>();
 
-        for (ClassLoader classLoader : registeredClassLoaders) {
-            getServiceClasses(classLoader, serviceInterface.getName(), classSet, false);
-            if (classSet.size() > 0)
-                break;
-        }
-        if (classSet.size() > 0)
-            return classSet.iterator().next().loadClass();
-        else
-            return null;
 
-    }
 
-    /**
-     * Returns a unique list of resource URLs of name META-INF/services/<name>
-     * Each URL is associated with the first ClassLoader that it was visible
-     * from
-     * 
-     * @param name Name of resource
-     * @return Table of URLs with associated ClassLoaders
-     * @throws IOException
-     */
-    public synchronized Hashtable<ClassLoader, Set<URL>> getServiceResources(final String name) throws IOException {
-
-        Hashtable<ClassLoader, Set<URL>> resourceTable = new Hashtable<ClassLoader, Set<URL>>();
-
-        HashSet<URL> allURLs = new HashSet<URL>();
-        for (final ClassLoader classLoader : registeredClassLoaders) {
-            HashSet<URL> urls = new HashSet<URL>();
-            resourceTable.put(classLoader, urls);
-            boolean debug = logger.isLoggable(Level.FINE);
-            if (debug) {
-                logger.fine("Discovering service resources using class loader " + classLoader);
-            }
-            // Allow privileged access to read META-INF/services/*. Add FilePermission to added to security policy file.
-            ArrayList<URL> urlList;
-            try {
-                // FIXME J2 Security - promote this to callers of this method
-                urlList = AccessController.doPrivileged(new PrivilegedExceptionAction<ArrayList<URL>>() {
-                    public ArrayList<URL> run() throws IOException {
-                        return Collections.list(classLoader.getResources("META-INF/services/" + name));
-                    }
-                });
-            } catch (PrivilegedActionException e) {
-                throw (IOException)e.getException();
-            }
-            
-            for (URL url : urlList) {
-                if (allURLs.contains(url))
-                    continue;
-                urls.add(url);
-            }
-            allURLs.addAll(urls);
-        }
-        return resourceTable;
-    }
 
-    /**
-     * Parse a service declaration in the form class;attr=value,attr=value and
-     * return a map of attributes
-     * 
-     * @param declaration
-     * @return a map of attributes
-     */
-    private Map<String, String> parseServiceDeclaration(String declaration) {
-        Map<String, String> attributes = new HashMap<String, String>();
-        int index = declaration.indexOf(';');
-        if (index != -1) {
-            attributes.put("class", declaration.substring(0, index).trim());
-            declaration = declaration.substring(index);
-        } else {
-            int j = declaration.indexOf('=');
-            if (j == -1) {
-                attributes.put("class", declaration.trim());
-                return attributes;
-            } else {
-                declaration = ";" + declaration;
-            }
-        }
-        StringTokenizer tokens = new StringTokenizer(declaration);
-        for (; tokens.hasMoreTokens();) {
-            String key = tokens.nextToken("=").substring(1).trim();
-            if (key == null)
-                break;
-            String value = tokens.nextToken(",").substring(1).trim();
-            if (value == null)
-                break;
-            attributes.put(key, value);
-        }
-        return attributes;
-    }
 
-    /**
-     * Load the service class whose name specified in a configuration file
-     * 
-     * @param classLoader
-     * @param name The name of the service class
-     * @param classSet Populate this set with classes extends/implements the
-     *                service class
-     * @throws IOException
-     */
-    private void getServiceClasses(final ClassLoader classLoader,
-                                   final String name,
-                                   Set<ServiceDeclaration> classSet,
-                                   boolean findAllClasses) throws IOException {
-
-        boolean debug = logger.isLoggable(Level.FINE);
-        if (debug) {
-            logger.fine("Discovering service providers using class loader " + classLoader);
-        }
-        // Allow privileged access to read META-INF/services/*. Add FilePermission to added to
-        // security policy file.
-        ArrayList<URL> urlList;
-        try {
-            urlList = AccessController.doPrivileged(new PrivilegedExceptionAction<ArrayList<URL>>() {
-                public ArrayList<URL> run() throws IOException {
-                    return Collections.list(classLoader.getResources("META-INF/services/" + name));
-                }
-            });
-        } catch (PrivilegedActionException e) {
-            throw (IOException)e.getException();
-        }
-        
-        for (final URL url : urlList) {
-            if (debug) {
-                logger.fine("Reading service provider file: " + url.toExternalForm());
-            }
-
-            // Allow privileged access to open URL stream. Add FilePermission to added to security
-            // policy file.
-            InputStream is;
-            try {
-                is = AccessController.doPrivileged(new PrivilegedExceptionAction<InputStream>() {
-                    public InputStream run() throws IOException {
-                        return url.openStream();
-                    }
-                });
-            } catch (PrivilegedActionException e) {
-                throw (IOException)e.getException();
-            }
-            BufferedReader reader = null;
-            try {
-                reader = new BufferedReader(new InputStreamReader(is));
-                while (true) {
-                    String line = reader.readLine();
-                    if (line == null)
-                        break;
-                    line = line.trim();
-                    if (!line.startsWith("#") && !"".equals(line)) {
-                        String reg = line.trim();
-                        if (debug) {
-                            logger.fine("Registering service provider: " + reg);
-                        }
-
-                        Map<String, String> attributes = parseServiceDeclaration(reg);
-                        String className = attributes.get("class");
-                        ServiceDeclaration serviceClass = new ServiceDeclaration(className, classLoader, attributes);
-                        classSet.add(serviceClass);
-
-                        if (!findAllClasses)
-                            break;
-                    }
-                }
-            } finally {
-                if (reader != null)
-                    reader.close();
-                if (is != null) {
-                    try {
-                        is.close();
-                    } catch (IOException ioe) {
-                    }
-                }
-            }
-            if (!findAllClasses && classSet.size() > 0)
-                break;
         }
+        return services.iterator().next().loadClass();
     }
 
 }
diff --git a/java/sca/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscovererTestCase.java b/java/sca/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscovererTestCase.java
new file mode 100644
index 0000000000..cf203cce7a
--- /dev/null
+++ b/java/sca/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ClasspathServiceDiscovererTestCase.java
@@ -0,0 +1,61 @@
+/*
+ * 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.tuscany.sca.extensibility;
+
+import java.util.Set;
+
+import junit.framework.Assert;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/**
+ * Test Case for ClasspathServiceDiscover
+ */
+public class ClasspathServiceDiscovererTestCase {
+    private static ClasspathServiceDiscover discover;
+
+    /**
+     * @throws java.lang.Exception
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+        discover = new ClasspathServiceDiscover(ClasspathServiceDiscover.class.getClassLoader());
+    }
+
+    @Test
+    public void testDiscovery() {
+        Set<ServiceDeclaration> discriptors =
+            discover.discover("org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint");
+        Assert.assertEquals(1, discriptors.size());
+        discriptors =
+            discover.discover("notthere");
+        Assert.assertEquals(0, discriptors.size());
+    }
+
+    /**
+     * @throws java.lang.Exception
+     */
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+}