Merge "Issue #1451 Allow overriding of IUserManager via ServiceLoader." into development

Former-commit-id: 4fe4daf973 [formerly 4fe4daf973 [formerly a1f84dbd0a1ef95c0303119f152396aaed6fcb16]]
Former-commit-id: 36c31ce6df
Former-commit-id: 6457ab4bdb

cave/com.raytheon.uf.viz.core/src/com/raytheon/uf/viz/core/auth/IUserManagerLoader.java

@@ -0,0 +1,47 @@
+/**
+ * This software was developed and / or modified by Raytheon Company,
+ * pursuant to Contract DG133W-05-CQ-1067 with the US Government.
+ * 
+ * U.S. EXPORT CONTROLLED TECHNICAL DATA
+ * This software product contains export-restricted data whose
+ * export/transfer/disclosure is restricted by U.S. law. Dissemination
+ * to non-U.S. persons whether in the United States or abroad requires
+ * an export license or other authorization.
+ * 
+ * Contractor Name:        Raytheon Company
+ * Contractor Address:     6825 Pine Street, Suite 340
+ *                         Mail Stop B8
+ *                         Omaha, NE 68106
+ *                         402.291.0100
+ * 
+ * See the AWIPS II Master Rights File ("Master Rights File.pdf") for
+ * further licensing information.
+ **/
+package com.raytheon.uf.viz.core.auth;
+
+/**
+ * Defines a method of retrieving the {@link IUserManager} implementation.
+ * Intentionally package-private as all access should be constrained to
+ * {@link UserController}.
+ * 
+ * <pre>
+ * 
+ * SOFTWARE HISTORY
+ * 
+ * Date         Ticket#    Engineer    Description
+ * ------------ ---------- ----------- --------------------------
+ * Jan 04, 2013 1451      djohnson     Initial creation
+ * 
+ * </pre>
+ * 
+ * @author djohnson
+ * @version 1.0
+ */
+interface IUserManagerLoader {
+    /**
+     * Load the {@link IUserManager} that should be used on the system.
+     * 
+     * @return the user manager
+     */
+    IUserManager getUserManager();
+}

cave/com.raytheon.uf.viz.core/src/com/raytheon/uf/viz/core/auth/UserController.java

@@ -38,6 +38,7 @@ import com.raytheon.uf.common.auth.user.IUser;
 import com.raytheon.uf.common.status.IUFStatusHandler;
 import com.raytheon.uf.common.status.UFStatus;
 import com.raytheon.uf.common.status.UFStatus.Priority;
+import com.raytheon.uf.common.util.ServiceLoaderUtil;
 import com.raytheon.uf.viz.core.exception.VizException;
 import com.raytheon.uf.viz.core.requests.INotAuthHandler;
 
@@ -51,6 +52,7 @@ import com.raytheon.uf.viz.core.requests.INotAuthHandler;
  * ------------ ---------- ----------- --------------------------
  * May 21, 2010            mschenke     Initial creation
  * Nov 06, 2012 1302       djohnson     Add ability to retrieve the {@link IUserManager}.
+ * Jan 04, 2013 1451       djohnson     Move static block code to an implementation of an interface.
  * 
  * </pre>
  * 
@@ -59,92 +61,125 @@ import com.raytheon.uf.viz.core.requests.INotAuthHandler;
  */
 
 public class UserController {
-    private static IUFStatusHandler statusHandler = UFStatus
-            .getHandler(UserController.class, "CAVE");
 
-    private static final String EXTENSION_POINT = "com.raytheon.uf.viz.core.userManager";
+    /**
+     * Loads the {@link IUserManager} implementation from extension points. This
+     * code was moved in verbatim from the static block below.
+     */
+    private static class ExtensionPointManagerLoader implements
+            IUserManagerLoader {
+        
+        private static final IUFStatusHandler statusHandler = UFStatus.getHandler(
+                ExtensionPointManagerLoader.class, "CAVE");
+        
+        private static final String EXTENSION_POINT = "com.raytheon.uf.viz.core.userManager";
 
-    private static IUserManager manager;
+        private static final ExtensionPointManagerLoader INSTANCE = new ExtensionPointManagerLoader();
+        
+        private ExtensionPointManagerLoader() {
+        }
 
-    static {
+        /**
-        IExtensionRegistry registry = Platform.getExtensionRegistry();
+         * {@inheritDoc}
-        IExtensionPoint point = registry.getExtensionPoint(EXTENSION_POINT);
+         */
-        if (point != null) {
+        @Override
-            IExtension[] extensions = point.getExtensions();
+        public IUserManager getUserManager() {
+            IUserManager manager = null;
 
-            for (IExtension ext : extensions) {
+            IExtensionRegistry registry = Platform.getExtensionRegistry();
-                for (IConfigurationElement elem : ext
+            IExtensionPoint point = registry.getExtensionPoint(EXTENSION_POINT);
-                        .getConfigurationElements()) {
+            if (point != null) {
-                    if (manager != null) {
+                IExtension[] extensions = point.getExtensions();
-                        statusHandler
+
-                                .handle(Priority.PROBLEM,
+                for (IExtension ext : extensions) {
-                                        "Not using user authentication manager: "
+                    for (IConfigurationElement elem : ext
-                                                + elem.getAttribute("class")
+                            .getConfigurationElements()) {
-                                                + ".\nViz does not currently support multiple authentication methods,"
+                        if (manager != null) {
-                                                + " using first one found in extension point.  Remove any authentication"
-                                                + " plugins not on edex server");
-                    } else {
-                        try {
-                            manager = (IUserManager) elem
-                                    .createExecutableExtension("class");
-                        } catch (CoreException e) {
                             statusHandler
                                     .handle(Priority.PROBLEM,
-                                            "Error creating IUserManager from extension point",
+                                            "Not using user authentication manager: "
-                                            e);
+                                                    + elem.getAttribute("class")
+                                                    + ".\nViz does not currently support multiple authentication methods,"
+                                                    + " using first one found in extension point.  Remove any authentication"
+                                                    + " plugins not on edex server");
+                        } else {
+                            try {
+                                manager = (IUserManager) elem
+                                        .createExecutableExtension("class");
+                            } catch (CoreException e) {
+                                statusHandler
+                                        .handle(Priority.PROBLEM,
+                                                "Error creating IUserManager from extension point",
+                                                e);
+                            }
                         }
                     }
                 }
             }
+
+            if (manager == null) {
+                manager = new IUserManager() {
+                    @Override
+                    public IUser getUserObject() {
+                        return null;
+                    }
+
+                    @Override
+                    public void updateUserObject(IUser user,
+                            IAuthenticationData authData) {
+
+                    }
+
+                    @Override
+                    public INotAuthHandler getNotAuthHandler() {
+                        return new INotAuthHandler() {
+                            @Override
+                            public Object notAuthenticated(
+                                    UserNotAuthenticated response)
+                                    throws VizException {
+                                throw new VizException(
+                                        "Could not perform request, user is not authenticated with server.");
+                            }
+
+                            @Override
+                            public Object notAuthorized(
+                                    UserNotAuthorized response)
+                                    throws VizException {
+                                throw new VizException(response.getMessage());
+                            }
+                        };
+                    }
+
+                    /**
+                     * {@inheritDoc}
+                     */
+                    @Override
+                    public List<IPermission> getPermissions(String application) {
+                        return Collections.emptyList();
+                    }
+
+                    @Override
+                    public List<IRole> getRoles(String application) {
+                        return Collections.emptyList();
+                    }
+
+                };
+            }
+            return manager;
         }
+    }
 
-        if (manager == null) {
+    private static final IUserManager manager;
-            manager = new IUserManager() {
+    static {
-                @Override
+        // This static block will perform exactly as before, with a few
-                public IUser getUserObject() {
+        // caveats...
-                    return null;
+        // If a service loader config file for the interface is present on the
-                }
+        // classpath, it can change the implementation, such as in a test case
+        IUserManagerLoader userManagerLoader = ServiceLoaderUtil.load(
+                IUserManagerLoader.class, ExtensionPointManagerLoader.INSTANCE);
 
-                @Override
+        // manager is now final, it can't be changed once it is initialized
-                public void updateUserObject(IUser user,
+        manager = userManagerLoader.getUserManager();
-                        IAuthenticationData authData) {
-
-                }
-
-                @Override
-                public INotAuthHandler getNotAuthHandler() {
-                    return new INotAuthHandler() {
-                        @Override
-                        public Object notAuthenticated(
-                                UserNotAuthenticated response)
-                                throws VizException {
-                            throw new VizException(
-                                    "Could not perform request, user is not authenticated with server.");
-                        }
-
-                        @Override
-                        public Object notAuthorized(UserNotAuthorized response)
-                                throws VizException {
-                            throw new VizException(response.getMessage());
-                        }
-                    };
-                }
-
-                /**
-                 * {@inheritDoc}
-                 */
-                @Override
-                public List<IPermission> getPermissions(String application) {
-                    return Collections.emptyList();
-                }
-
-                @Override
-                public List<IRole> getRoles(String application) {
-                    return Collections.emptyList();
-                }
-
-            };
-        }
     }
 
 

edexOsgi/com.raytheon.uf.common.util/src/com/raytheon/uf/common/util/ServiceLoaderUtil.java

@@ -0,0 +1,72 @@
+/**
+ * This software was developed and / or modified by Raytheon Company,
+ * pursuant to Contract DG133W-05-CQ-1067 with the US Government.
+ * 
+ * U.S. EXPORT CONTROLLED TECHNICAL DATA
+ * This software product contains export-restricted data whose
+ * export/transfer/disclosure is restricted by U.S. law. Dissemination
+ * to non-U.S. persons whether in the United States or abroad requires
+ * an export license or other authorization.
+ * 
+ * Contractor Name:        Raytheon Company
+ * Contractor Address:     6825 Pine Street, Suite 340
+ *                         Mail Stop B8
+ *                         Omaha, NE 68106
+ *                         402.291.0100
+ * 
+ * See the AWIPS II Master Rights File ("Master Rights File.pdf") for
+ * further licensing information.
+ **/
+package com.raytheon.uf.common.util;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+
+/**
+ * Utilities for interacting with {@link ServiceLoader}.
+ * 
+ * <pre>
+ * 
+ * SOFTWARE HISTORY
+ * 
+ * Date         Ticket#    Engineer    Description
+ * ------------ ---------- ----------- --------------------------
+ * Jan 04, 2013 1451       djohnson     Initial creation
+ * 
+ * </pre>
+ * 
+ * @author djohnson
+ * @version 1.0
+ */
+
+public final class ServiceLoaderUtil {
+    /**
+     * Prevent construction.
+     */
+    private ServiceLoaderUtil() {
+    }
+
+    /**
+     * Loads the first implementation of an interface found using
+     * {@link ServiceLoader}. If no results are found, will return the provided
+     * default implementation.
+     * 
+     * @param interfaceClass
+     *            the class instance to search for a service loader
+     *            implementation of
+     * @param defaultImplementation
+     *            the default implementation
+     * @return the loaded implementation, or the default implementation is no
+     *         configuration file found
+     */
+    public static <T> T load(Class<T> interfaceClass, T defaultImplementation) {
+        ServiceLoader<T> overridden = ServiceLoader.load(interfaceClass);
+
+        final Iterator<T> iter = overridden.iterator();
+        if (iter.hasNext()) {
+            return iter.next();
+        }
+
+        return defaultImplementation;
+    }
+}