jdk/test/javax/management/MBeanServer/OldMBeanServerTest.java
changeset 1004 5ba8217eb504
child 1247 b4c26443dee5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/management/MBeanServer/OldMBeanServerTest.java	Thu Jul 31 15:31:13 2008 +0200
@@ -0,0 +1,1410 @@
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.Serializable;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.management.ManagementFactory;
+import java.lang.ref.WeakReference;
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.WeakHashMap;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import javax.management.Attribute;
+import javax.management.AttributeList;
+import javax.management.AttributeNotFoundException;
+import javax.management.DynamicMBean;
+import javax.management.InstanceAlreadyExistsException;
+import javax.management.InstanceNotFoundException;
+import javax.management.IntrospectionException;
+import javax.management.InvalidAttributeValueException;
+import javax.management.ListenerNotFoundException;
+import javax.management.MBeanAttributeInfo;
+import javax.management.MBeanConstructorInfo;
+import javax.management.MBeanException;
+import javax.management.MBeanInfo;
+import javax.management.MBeanNotificationInfo;
+import javax.management.MBeanOperationInfo;
+import javax.management.MBeanRegistration;
+import javax.management.MBeanRegistrationException;
+import javax.management.MBeanServer;
+import javax.management.MBeanServerBuilder;
+import javax.management.MBeanServerConnection;
+import javax.management.MBeanServerDelegate;
+import javax.management.MBeanServerFactory;
+import javax.management.MBeanServerNotification;
+import javax.management.MalformedObjectNameException;
+import javax.management.NotCompliantMBeanException;
+import javax.management.Notification;
+import javax.management.NotificationBroadcaster;
+import javax.management.NotificationBroadcasterSupport;
+import javax.management.NotificationEmitter;
+import javax.management.NotificationFilter;
+import javax.management.NotificationListener;
+import javax.management.ObjectInstance;
+import javax.management.ObjectName;
+import javax.management.OperationsException;
+import javax.management.QueryEval;
+import javax.management.QueryExp;
+import javax.management.ReflectionException;
+import javax.management.RuntimeErrorException;
+import javax.management.RuntimeMBeanException;
+import javax.management.StandardMBean;
+import javax.management.loading.ClassLoaderRepository;
+import javax.management.remote.JMXConnector;
+import javax.management.remote.JMXConnectorFactory;
+import javax.management.remote.JMXConnectorServer;
+import javax.management.remote.JMXConnectorServerFactory;
+import javax.management.remote.JMXServiceURL;
+
+/*
+ * @test OldMBeanServerTest.java
+ * @bug 5072268
+ * @summary Test that nothing assumes a post-1.2 MBeanServer
+ * @author Eamonn McManus
+ * @run main/othervm -ea OldMBeanServerTest
+ */
+
+/*
+ * We defined the MBeanServerBuilder class and the associated system
+ * property javax.management.builder.initial in version 1.2 of the JMX
+ * spec.  That amounts to a guarantee that someone can set the property
+ * to an MBeanServer that only knows about JMX 1.2 semantics, and if they
+ * only do JMX 1.2 operations, everything should work.  This test is a
+ * sanity check that ensures we don't inadvertently make any API changes
+ * that stop that from being true.  It includes a complete (if slow)
+ * MBeanServer implementation.  That implementation doesn't replicate the
+ * mandated exception behaviour everywhere, though, since there's lots of
+ * arbitrary cruft in that.  Also, the behaviour of concurrent unregisterMBean
+ * calls is incorrect in detail.
+ */
+
+public class OldMBeanServerTest {
+    private static MBeanServerConnection mbsc;
+    private static String failure;
+
+    public static void main(String[] args) throws Exception {
+        if (!OldMBeanServerTest.class.desiredAssertionStatus())
+            throw new Exception("Test must be run with -ea");
+
+        System.setProperty("javax.management.builder.initial",
+                OldMBeanServerBuilder.class.getName());
+        assert MBeanServerFactory.newMBeanServer() instanceof OldMBeanServer;
+
+        System.out.println("=== RUNNING TESTS WITH LOCAL MBEANSERVER ===");
+        runTests(new Callable<MBeanServerConnection>() {
+            public MBeanServerConnection call() {
+                return MBeanServerFactory.newMBeanServer();
+            }
+        }, null);
+
+        System.out.println("=== RUNNING TESTS THROUGH CONNECTOR ===");
+        ConnectionBuilder builder = new ConnectionBuilder();
+        runTests(builder, builder);
+
+        if (failure == null)
+            System.out.println("TEST PASSED");
+        else
+            throw new Exception("TEST FAILED: " + failure);
+    }
+
+    private static class ConnectionBuilder
+            implements Callable<MBeanServerConnection>, Runnable {
+        private JMXConnector connector;
+        public MBeanServerConnection call() {
+            MBeanServer mbs = MBeanServerFactory.newMBeanServer();
+            try {
+                JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://");
+                JMXConnectorServer cs =
+                    JMXConnectorServerFactory.newJMXConnectorServer(
+                        url, null, mbs);
+                cs.start();
+                JMXServiceURL addr = cs.getAddress();
+                connector = JMXConnectorFactory.connect(addr);
+                return connector.getMBeanServerConnection();
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        }
+        public void run() {
+            if (connector != null) {
+                try {
+                    connector.close();
+                } catch (IOException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        }
+    }
+
+    private static void runTests(
+            Callable<MBeanServerConnection> maker, Runnable breaker)
+    throws Exception {
+        for (Method m : OldMBeanServerTest.class.getDeclaredMethods()) {
+            if (Modifier.isStatic(m.getModifiers()) &&
+                    m.getName().startsWith("test") &&
+                    m.getParameterTypes().length == 0) {
+                ExpectException expexc = m.getAnnotation(ExpectException.class);
+                mbsc = maker.call();
+                try {
+                    m.invoke(null);
+                    if (expexc != null) {
+                        failure =
+                                m.getName() + " did not got expected exception " +
+                                expexc.value().getName();
+                        System.out.println(failure);
+                    } else
+                        System.out.println(m.getName() + " OK");
+                } catch (InvocationTargetException ite) {
+                    Throwable t = ite.getCause();
+                    String prob = null;
+                    if (expexc != null) {
+                        if (expexc.value().isInstance(t)) {
+                            System.out.println(m.getName() + " OK (got expected " +
+                                    expexc.value().getName() + ")");
+                        } else
+                            prob = "got wrong exception";
+                    } else
+                        prob = "got exception";
+                    if (prob != null) {
+                        failure = m.getName() + ": " + prob + " " +
+                                t.getClass().getName();
+                        System.out.println(failure);
+                        t.printStackTrace(System.out);
+                    }
+                } finally {
+                    if (breaker != null)
+                        breaker.run();
+                }
+            }
+        }
+    }
+
+    @Retention(RetentionPolicy.RUNTIME)
+    private static @interface ExpectException {
+        Class<? extends Exception> value();
+    }
+
+    public static interface BoringMBean {
+        public String getName();
+        public int add(int x, int y);
+    }
+
+    // This class is Serializable so we can createMBean a StandardMBean
+    // that contains it.  Not recommended practice in general --
+    // should we have a StandardMBean constructor that takes a class
+    // name and constructor parameters?
+    public static class Boring implements BoringMBean, Serializable {
+        public String getName() {
+            return "Jessica";
+        }
+
+        public int add(int x, int y) {
+            return x + y;
+        }
+    }
+
+    public static interface BoringNotifierMBean extends BoringMBean {
+        public void send();
+    }
+
+    public static class BoringNotifier
+            extends Boring implements BoringNotifierMBean, NotificationBroadcaster {
+        private final NotificationBroadcasterSupport nbs =
+                new NotificationBroadcasterSupport();
+
+        public void addNotificationListener(
+                NotificationListener listener, NotificationFilter filter, Object handback)
+        throws IllegalArgumentException {
+            nbs.addNotificationListener(listener, filter, handback);
+        }
+
+        public void removeNotificationListener(NotificationListener listener)
+        throws ListenerNotFoundException {
+            nbs.removeNotificationListener(listener);
+        }
+
+        public MBeanNotificationInfo[] getNotificationInfo() {
+            return null;
+        }
+
+        public void send() {
+            Notification n = new Notification("type.type", this, 0L);
+            nbs.sendNotification(n);
+        }
+    }
+
+    private static class CountListener implements NotificationListener {
+        volatile int count;
+        public void handleNotification(Notification n, Object h) {
+            if (h == null)
+                h = 1;
+            count += (Integer) h;
+        }
+        void waitForCount(int expect) throws InterruptedException {
+            long deadline = System.currentTimeMillis() + 2000L;
+            while (count < expect && System.currentTimeMillis() < deadline)
+                Thread.sleep(1);
+            assert count == expect;
+        }
+    }
+
+    private static void testBasic() throws Exception {
+        CountListener countListener = new CountListener();
+        mbsc.addNotificationListener(
+                MBeanServerDelegate.DELEGATE_NAME, countListener, null, null);
+        assert countListener.count == 0;
+        ObjectName name = new ObjectName("a:b=c");
+        if (mbsc instanceof MBeanServer)
+            ((MBeanServer) mbsc).registerMBean(new Boring(), name);
+        else
+            mbsc.createMBean(Boring.class.getName(), name);
+        countListener.waitForCount(1);
+        assert mbsc.isRegistered(name);
+        assert mbsc.queryNames(null, null).contains(name);
+        assert mbsc.getAttribute(name, "Name").equals("Jessica");
+        assert mbsc.invoke(
+                name, "add", new Object[] {2, 3}, new String[] {"int", "int"})
+                .equals(5);
+        mbsc.unregisterMBean(name);
+        countListener.waitForCount(2);
+        assert !mbsc.isRegistered(name);
+        assert !mbsc.queryNames(null, null).contains(name);
+
+        mbsc.createMBean(BoringNotifier.class.getName(), name);
+        countListener.waitForCount(3);
+        CountListener boringListener = new CountListener();
+        class AlwaysNotificationFilter implements NotificationFilter {
+            public boolean isNotificationEnabled(Notification notification) {
+                return true;
+            }
+        }
+        mbsc.addNotificationListener(
+                name, boringListener, new AlwaysNotificationFilter(), 5);
+        mbsc.invoke(name, "send", null, null);
+        boringListener.waitForCount(5);
+    }
+
+    private static void testPrintAttrs() throws Exception {
+        printAttrs(mbsc, null);
+    }
+
+    private static void testPlatformMBeanServer() throws Exception {
+        MBeanServer pmbs = ManagementFactory.getPlatformMBeanServer();
+        assert pmbs instanceof OldMBeanServer;
+        // Preceding assertion could be violated if at some stage we wrap
+        // the Platform MBeanServer.  In that case we can still check that
+        // it is ultimately an OldMBeanServer for example by adding a
+        // counter to getAttribute and checking that it is incremented
+        // when we call pmbs.getAttribute.
+
+        printAttrs(pmbs, UnsupportedOperationException.class);
+        ObjectName memoryMXBeanName =
+                new ObjectName(ManagementFactory.MEMORY_MXBEAN_NAME);
+        pmbs.invoke(memoryMXBeanName, "gc", null, null);
+    }
+
+    private static void printAttrs(
+            MBeanServerConnection mbsc1, Class<? extends Exception> expectX)
+    throws Exception {
+        Set<ObjectName> names = mbsc1.queryNames(null, null);
+        for (ObjectName name : names) {
+            System.out.println(name + ":");
+            MBeanInfo mbi = mbsc1.getMBeanInfo(name);
+            MBeanAttributeInfo[] mbais = mbi.getAttributes();
+            for (MBeanAttributeInfo mbai : mbais) {
+                String attr = mbai.getName();
+                Object value;
+                try {
+                    value = mbsc1.getAttribute(name, attr);
+                } catch (Exception e) {
+                    if (expectX != null && expectX.isInstance(e))
+                        value = "<" + e + ">";
+                    else
+                        throw e;
+                }
+                String s = "  " + attr + " = " + value;
+                if (s.length() > 80)
+                    s = s.substring(0, 77) + "...";
+                System.out.println(s);
+            }
+        }
+    }
+
+    private static void testJavaxManagementStandardMBean() throws Exception {
+        ObjectName name = new ObjectName("a:b=c");
+        Object mbean = new StandardMBean(new Boring(), BoringMBean.class);
+        mbsc.createMBean(
+                StandardMBean.class.getName(), name,
+                new Object[] {new Boring(), BoringMBean.class},
+                new String[] {Object.class.getName(), Class.class.getName()});
+        assert mbsc.getAttribute(name, "Name").equals("Jessica");
+        assert mbsc.invoke(
+                name, "add", new Object[] {2, 3}, new String[] {"int", "int"})
+                .equals(5);
+        mbsc.unregisterMBean(name);
+    }
+
+    private static void testConnector() throws Exception {
+    }
+
+    public static class OldMBeanServerBuilder extends MBeanServerBuilder {
+        public MBeanServer newMBeanServer(
+                String defaultDomain, MBeanServer outer, MBeanServerDelegate delegate) {
+            return new OldMBeanServer(defaultDomain, delegate);
+        }
+    }
+
+    public static class OldMBeanServer implements MBeanServer {
+        // We pretend there's a ClassLoader MBean representing the Class Loader
+        // Repository and intercept references to it where necessary to keep up
+        // the pretence.  This allows us to fake the right behaviour for
+        // the omitted-ClassLoader versions of createMBean and instantiate
+        // (which are not the same as passing a null for the ClassLoader parameter
+        // of the versions that have one).
+        private static final ObjectName clrName;
+        static {
+            try {
+                clrName =
+                        new ObjectName("JMImplementation:type=ClassLoaderRepository");
+            } catch (MalformedObjectNameException e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        private final ConcurrentMap<ObjectName, DynamicMBean> mbeans =
+                new ConcurrentHashMap<ObjectName, DynamicMBean>();
+        private final ConcurrentMap<ObjectName, ListenerTable> listenerMap =
+                new ConcurrentHashMap<ObjectName, ListenerTable>();
+        private final String defaultDomain;
+        private final MBeanServerDelegate delegate;
+        private final ClassLoaderRepositoryImpl clr =
+                new ClassLoaderRepositoryImpl();
+
+        OldMBeanServer(String defaultDomain, MBeanServerDelegate delegate) {
+            this.defaultDomain = defaultDomain;
+            this.delegate = delegate;
+            try {
+                registerMBean(delegate, MBeanServerDelegate.DELEGATE_NAME);
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        }
+
+        public ObjectInstance createMBean(String className, ObjectName name)
+        throws ReflectionException, InstanceAlreadyExistsException,
+                MBeanRegistrationException, MBeanException,
+                NotCompliantMBeanException {
+            return createMBean(className, name, null, null);
+        }
+
+        public ObjectInstance createMBean(
+                String className, ObjectName name, ObjectName loaderName)
+        throws ReflectionException, InstanceAlreadyExistsException,
+                MBeanRegistrationException, MBeanException,
+                NotCompliantMBeanException, InstanceNotFoundException {
+            return createMBean(className, name, loaderName, null, null);
+        }
+
+        public ObjectInstance createMBean(
+                String className, ObjectName name, Object[] params, String[] signature)
+        throws ReflectionException, InstanceAlreadyExistsException,
+                MBeanRegistrationException, MBeanException,
+                NotCompliantMBeanException {
+            try {
+                return createMBean(className, name, clrName, params, signature);
+            } catch (InstanceNotFoundException ex) {
+                throw new RuntimeException(ex);  // can't happen
+            }
+        }
+
+        public ObjectInstance createMBean(
+                String className, ObjectName name, ObjectName loaderName,
+                Object[] params, String[] signature)
+        throws ReflectionException, InstanceAlreadyExistsException,
+                MBeanRegistrationException, MBeanException,
+                NotCompliantMBeanException, InstanceNotFoundException {
+            Object mbean = instantiate(className, loaderName, params, signature);
+            return registerMBean(mbean, name);
+        }
+
+        private void forbidJMImpl(ObjectName name) {
+            if (name.getDomain().equals("JMImplementation") &&
+                    mbeans.containsKey(MBeanServerDelegate.DELEGATE_NAME))
+                throw new IllegalArgumentException("JMImplementation reserved");
+        }
+
+        public ObjectInstance registerMBean(Object object, ObjectName name)
+        throws InstanceAlreadyExistsException, MBeanRegistrationException,
+                NotCompliantMBeanException {
+            forbidJMImpl(name);
+            if (name.isPattern())
+                throw new IllegalArgumentException(name.toString());
+            // This is the only place we check for wildcards.  Since you
+            // can't register a wildcard name, other operations that supply
+            // one will get InstanceNotFoundException when they look it up.
+
+            DynamicMBean mbean;
+            if (object instanceof DynamicMBean)
+                mbean = (DynamicMBean) object;
+            else
+                mbean = standardToDynamic(object);
+            MBeanRegistration reg = mbeanRegistration(object);
+            try {
+                name = reg.preRegister(this, name);
+            } catch (Exception e) {
+                throw new MBeanRegistrationException(e);
+            }
+            DynamicMBean put = mbeans.putIfAbsent(name, mbean);
+            if (put != null) {
+                reg.postRegister(false);
+                throw new InstanceAlreadyExistsException(name.toString());
+            }
+            reg.postRegister(true);
+
+            if (object instanceof ClassLoader)
+                clr.addLoader((ClassLoader) object);
+
+            Notification n = new MBeanServerNotification(
+                    MBeanServerNotification.REGISTRATION_NOTIFICATION,
+                    MBeanServerDelegate.DELEGATE_NAME,
+                    0,
+                    name);
+            delegate.sendNotification(n);
+
+            String className = mbean.getMBeanInfo().getClassName();
+            return new ObjectInstance(name, className);
+        }
+
+        public void unregisterMBean(ObjectName name)
+        throws InstanceNotFoundException, MBeanRegistrationException {
+
+            forbidJMImpl(name);
+
+            DynamicMBean mbean = getMBean(name);
+            if (mbean == null)
+                throw new InstanceNotFoundException(name.toString());
+
+            MBeanRegistration reg = mbeanRegistration(mbean);
+            try {
+                reg.preDeregister();
+            } catch (Exception e) {
+                throw new MBeanRegistrationException(e);
+            }
+            if (!mbeans.remove(name, mbean))
+                throw new InstanceNotFoundException(name.toString());
+                // This is incorrect because we've invoked preDeregister
+
+            Object userMBean = getUserMBean(mbean);
+            if (userMBean instanceof ClassLoader)
+                clr.removeLoader((ClassLoader) userMBean);
+
+            Notification n = new MBeanServerNotification(
+                    MBeanServerNotification.REGISTRATION_NOTIFICATION,
+                    MBeanServerDelegate.DELEGATE_NAME,
+                    0,
+                    name);
+            delegate.sendNotification(n);
+
+            reg.postDeregister();
+        }
+
+        public ObjectInstance getObjectInstance(ObjectName name)
+        throws InstanceNotFoundException {
+            DynamicMBean mbean = getMBean(name);
+            return new ObjectInstance(name, mbean.getMBeanInfo().getClassName());
+        }
+
+        private static class TrueQueryExp implements QueryExp {
+            public boolean apply(ObjectName name) {
+                return true;
+            }
+
+            public void setMBeanServer(MBeanServer s) {}
+        }
+        private static final QueryExp trueQuery = new TrueQueryExp();
+
+        public Set<ObjectInstance> queryMBeans(ObjectName name, QueryExp query) {
+            Set<ObjectInstance> instances = newSet();
+            if (name == null)
+                name = ObjectName.WILDCARD;
+            if (query == null)
+                query = trueQuery;
+            MBeanServer oldMBS = QueryEval.getMBeanServer();
+            try {
+                query.setMBeanServer(this);
+                for (ObjectName n : mbeans.keySet()) {
+                    if (name.apply(n)) {
+                        try {
+                            if (query.apply(n))
+                                instances.add(getObjectInstance(n));
+                        } catch (Exception e) {
+                            // OK: Ignore this MBean in the result
+                        }
+                    }
+                }
+            } finally {
+                query.setMBeanServer(oldMBS);
+            }
+            return instances;
+        }
+
+        public Set<ObjectName> queryNames(ObjectName name, QueryExp query) {
+            Set<ObjectInstance> instances = queryMBeans(name, query);
+            Set<ObjectName> names = newSet();
+            for (ObjectInstance instance : instances)
+                names.add(instance.getObjectName());
+            return names;
+        }
+
+        public boolean isRegistered(ObjectName name) {
+            return mbeans.containsKey(name);
+        }
+
+        public Integer getMBeanCount() {
+            return mbeans.size();
+        }
+
+        public Object getAttribute(ObjectName name, String attribute)
+        throws MBeanException, AttributeNotFoundException,
+                InstanceNotFoundException, ReflectionException {
+            return getMBean(name).getAttribute(attribute);
+        }
+
+        public AttributeList getAttributes(ObjectName name, String[] attributes)
+        throws InstanceNotFoundException, ReflectionException {
+            return getMBean(name).getAttributes(attributes);
+        }
+
+        public void setAttribute(ObjectName name, Attribute attribute)
+        throws InstanceNotFoundException, AttributeNotFoundException,
+                InvalidAttributeValueException, MBeanException,
+                ReflectionException {
+            getMBean(name).setAttribute(attribute);
+        }
+
+        public AttributeList setAttributes(
+                ObjectName name, AttributeList attributes)
+        throws InstanceNotFoundException, ReflectionException {
+            return getMBean(name).setAttributes(attributes);
+        }
+
+        public Object invoke(
+                ObjectName name, String operationName, Object[] params,
+                String[] signature)
+        throws InstanceNotFoundException, MBeanException, ReflectionException {
+            return getMBean(name).invoke(operationName, params, signature);
+        }
+
+        public String getDefaultDomain() {
+            return defaultDomain;
+        }
+
+        public String[] getDomains() {
+            Set<String> domains = newSet();
+            for (ObjectName name : mbeans.keySet())
+                domains.add(name.getDomain());
+            return domains.toArray(new String[0]);
+        }
+
+        // ClassCastException if MBean is not a NotificationBroadcaster
+        public void addNotificationListener(
+                ObjectName name, NotificationListener listener,
+                NotificationFilter filter, Object handback)
+                throws InstanceNotFoundException {
+            NotificationBroadcaster userMBean =
+                    (NotificationBroadcaster) getUserMBean(name);
+            NotificationListener wrappedListener =
+                  wrappedListener(name, userMBean, listener);
+            userMBean.addNotificationListener(wrappedListener, filter, handback);
+        }
+
+        public void addNotificationListener(
+                ObjectName name, ObjectName listener,
+                NotificationFilter filter, Object handback)
+                throws InstanceNotFoundException {
+            NotificationListener nl =
+                    (NotificationListener) getUserMBean(listener);
+            addNotificationListener(name, nl, filter, handback);
+        }
+
+        public void removeNotificationListener(
+                ObjectName name, ObjectName listener)
+                throws InstanceNotFoundException, ListenerNotFoundException {
+            NotificationListener nl =
+                    (NotificationListener) getUserMBean(listener);
+            removeNotificationListener(name, nl);
+        }
+
+        public void removeNotificationListener(
+                ObjectName name, ObjectName listener,
+                NotificationFilter filter, Object handback)
+                throws InstanceNotFoundException, ListenerNotFoundException {
+            NotificationListener nl =
+                    (NotificationListener) getUserMBean(listener);
+            removeNotificationListener(name, nl, filter, handback);
+        }
+
+        public void removeNotificationListener(
+                ObjectName name, NotificationListener listener)
+                throws InstanceNotFoundException, ListenerNotFoundException {
+            NotificationBroadcaster userMBean =
+                    (NotificationBroadcaster) getUserMBean(name);
+            NotificationListener wrappedListener =
+                  wrappedListener(name, userMBean, listener);
+            userMBean.removeNotificationListener(wrappedListener);
+        }
+
+        public void removeNotificationListener(
+                ObjectName name, NotificationListener listener,
+                NotificationFilter filter, Object handback)
+                throws InstanceNotFoundException, ListenerNotFoundException {
+            NotificationEmitter userMBean =
+                    (NotificationEmitter) getMBean(name);
+            NotificationListener wrappedListener =
+                  wrappedListener(name, userMBean, listener);
+            userMBean.removeNotificationListener(wrappedListener, filter, handback);
+        }
+
+        public MBeanInfo getMBeanInfo(ObjectName name)
+        throws InstanceNotFoundException, IntrospectionException,
+                ReflectionException {
+            return getMBean(name).getMBeanInfo();
+        }
+
+        public boolean isInstanceOf(ObjectName name, String className)
+        throws InstanceNotFoundException {
+            DynamicMBean mbean = getMBean(name);
+            String mbeanClassName = mbean.getMBeanInfo().getClassName();
+            if (className.equals(mbeanClassName))
+                return true;
+            ClassLoader loader = getUserMBean(mbean).getClass().getClassLoader();
+            try {
+                Class<?> mbeanClass = Class.forName(mbeanClassName, false, loader);
+                Class<?> isInstClass = Class.forName(className, false, loader);
+                return isInstClass.isAssignableFrom(mbeanClass);
+            } catch (ClassNotFoundException e) {
+                return false;
+            }
+        }
+
+        public Object instantiate(String className)
+        throws ReflectionException, MBeanException {
+            return instantiate(className, null, null);
+        }
+
+        public Object instantiate(String className, ObjectName loaderName)
+        throws ReflectionException, MBeanException, InstanceNotFoundException {
+            return instantiate(className, loaderName, null, null);
+        }
+
+        public Object instantiate(
+                String className, Object[] params, String[] signature)
+        throws ReflectionException, MBeanException {
+            try {
+                return instantiate(className, clrName, params, signature);
+            } catch (InstanceNotFoundException e) {
+                throw new RuntimeException(e);  // can't happen
+            }
+        }
+
+        public Object instantiate(
+                String className, ObjectName loaderName,
+                Object[] params, String[] signature)
+        throws ReflectionException, MBeanException, InstanceNotFoundException {
+
+            if (params == null)
+                params = new Object[0];
+            if (signature == null)
+                signature = new String[0];
+
+            ClassLoader loader;
+            if (loaderName == null)
+                loader = this.getClass().getClassLoader();
+            else if (loaderName.equals(clrName))
+                loader = clr;
+            else
+                loader = (ClassLoader) getMBean(loaderName);
+
+            Class<?> c;
+            try {
+                c = Class.forName(className, false, loader);
+            } catch (ClassNotFoundException e) {
+                throw new ReflectionException(e);
+            }
+
+            Constructor[] constrs = c.getConstructors();
+            Constructor found = null;
+            findconstr:
+            for (Constructor constr : constrs) {
+                Class<?>[] cTypes = constr.getParameterTypes();
+                if (cTypes.length == signature.length) {
+                    for (int i = 0; i < cTypes.length; i++) {
+                        if (!cTypes[i].getName().equals(signature[i]))
+                            continue findconstr;
+                    }
+                    found = constr;
+                    break findconstr;
+                }
+            }
+            if (found == null) {
+                Exception x = new NoSuchMethodException(
+                        className + Arrays.toString(signature));
+                throw new ReflectionException(x);
+            }
+            return invokeSomething(found, null, params);
+        }
+
+        @Deprecated
+        public ObjectInputStream deserialize(ObjectName name, byte[] data)
+        throws InstanceNotFoundException, OperationsException {
+            throw new UnsupportedOperationException();
+        }
+
+        @Deprecated
+        public ObjectInputStream deserialize(String className, byte[] data)
+        throws OperationsException, ReflectionException {
+            throw new UnsupportedOperationException();
+        }
+
+        @Deprecated
+        public ObjectInputStream deserialize(
+                String className, ObjectName loaderName, byte[] data)
+        throws InstanceNotFoundException, OperationsException, ReflectionException {
+            throw new UnsupportedOperationException();
+        }
+
+        public ClassLoader getClassLoaderFor(ObjectName mbeanName)
+        throws InstanceNotFoundException {
+            DynamicMBean mbean = getMBean(mbeanName);
+            Object userMBean = getUserMBean(mbean);
+            return userMBean.getClass().getClassLoader();
+        }
+
+        public ClassLoader getClassLoader(ObjectName loaderName)
+        throws InstanceNotFoundException {
+            return (ClassLoader) getMBean(loaderName);
+        }
+
+        public ClassLoaderRepository getClassLoaderRepository() {
+            return new ClassLoaderRepository() {
+                public Class<?> loadClass(String className)
+                throws ClassNotFoundException {
+                    return clr.loadClass(className);
+                }
+
+                public Class<?> loadClassWithout(
+                        ClassLoader exclude, String className)
+                throws ClassNotFoundException {
+                    return clr.loadClassWithout(exclude, className);
+                }
+
+                public Class<?> loadClassBefore(
+                        ClassLoader stop, String className)
+                throws ClassNotFoundException {
+                    return clr.loadClassBefore(stop, className);
+                }
+            };
+        }
+
+        private static class ClassLoaderRepositoryImpl
+                extends ClassLoader implements ClassLoaderRepository {
+            private List<ClassLoader> loaders = newList();
+            {
+                loaders.add(this.getClass().getClassLoader());
+                // We also behave as if the system class loader were in
+                // the repository, since we do nothing to stop delegation
+                // to the parent, which is the system class loader, and
+                // that delegation happens before our findClass is called.
+            }
+
+            void addLoader(ClassLoader loader) {
+                loaders.add(loader);
+            }
+
+            void removeLoader(ClassLoader loader) {
+                if (!loaders.remove(loader))
+                    throw new RuntimeException("Loader was not in CLR!");
+            }
+
+            public Class<?> loadClassWithout(
+                    ClassLoader exclude, String className)
+                    throws ClassNotFoundException {
+                return loadClassWithoutBefore(exclude, null, className);
+            }
+
+            public Class<?> loadClassBefore(ClassLoader stop, String className)
+            throws ClassNotFoundException {
+                return loadClassWithoutBefore(null, stop, className);
+            }
+
+            private Class<?> loadClassWithoutBefore(
+                    ClassLoader exclude, ClassLoader stop, String className)
+                    throws ClassNotFoundException {
+                for (ClassLoader loader : loaders) {
+                    if (loader == exclude)
+                        continue;
+                    if (loader == stop)
+                        break;
+                    try {
+                        return Class.forName(className, false, loader);
+                    } catch (ClassNotFoundException e) {
+                        // OK: try others
+                    }
+                }
+                throw new ClassNotFoundException(className);
+            }
+
+            @Override
+            protected Class<?> findClass(String className)
+            throws ClassNotFoundException {
+                return loadClassWithout(null, className);
+            }
+        }
+
+        /* There is zero or one ListenerTable per MBean.
+         * The ListenerTable stuff is complicated.  We want to rewrite the
+         * source of notifications so that if the source of a notification
+         * from the MBean X is a reference to X itself, it gets replaced
+         * by X's ObjectName.  To do this, we wrap the user's listener in
+         * a RewriteListener.  But if the same listener is added a second
+         * time (perhaps with a different filter or handback) we must
+         * reuse the same RewriteListener so that the two-argument
+         * removeNotificationListener(ObjectName,NotificationListener) will
+         * correctly remove both listeners. This means we must remember the
+         * mapping from listener to WrappedListener.  But if the MBean
+         * discards its listeners (as a result of removeNL or spontaneously)
+         * then we don't want to keep a reference to the WrappedListener.
+         * So we have tons of WeakReferences.  The key in the ListenerTable
+         * is an IdentityListener, which wraps the user's listener to ensure
+         * that identity and not equality is used during the lookup, even if
+         * the user's listener has an equals method.  The value in the
+         * ListenerTable is a WeakReference wrapping a RewriteListener wrapping
+         * the same IdentityListener.  Since the RewriteListener is what is
+         * added to the user's MBean, the WeakReference won't disappear as long
+         * as the MBean still has this listener.  And since it references the
+         * IdentityListener, that won't disappear either.  But once the
+         * RewriteListener is no longer referenced by the user's MBean,
+         * there's nothing to stop its WeakReference from being cleared,
+         * and then corresponding IdentityListener that is now only weakly
+         * referenced from the key in the table.
+         */
+        private static class ListenerTable
+                extends WeakHashMap<NotificationListener,
+                                    WeakReference<NotificationListener>> {
+        }
+
+        private static class IdentityListener implements NotificationListener {
+            private final NotificationListener userListener;
+
+            IdentityListener(NotificationListener userListener) {
+                this.userListener = userListener;
+            }
+
+            public void handleNotification(
+                    Notification notification, Object handback) {
+                userListener.handleNotification(notification, handback);
+            }
+
+            @Override
+            public boolean equals(Object o) {
+                return (this == o);
+            }
+
+            @Override
+            public int hashCode() {
+                return System.identityHashCode(this);
+            }
+        }
+
+        private static class RewriteListener implements NotificationListener {
+            private final ObjectName name;
+            private final Object userMBean;
+            private final NotificationListener userListener;
+
+            RewriteListener(
+                    ObjectName name, Object userMBean,
+                    NotificationListener userListener) {
+                this.name = name;
+                this.userMBean = userMBean;
+                this.userListener = userListener;
+            }
+
+            public void handleNotification(
+                    Notification notification, Object handback) {
+                if (notification.getSource() == userMBean)
+                    notification.setSource(name);
+                userListener.handleNotification(notification, handback);
+            }
+        }
+
+        private NotificationListener wrappedListener(
+                ObjectName name, Object userMBean, NotificationListener userListener)
+        throws InstanceNotFoundException {
+            ListenerTable table = new ListenerTable();
+            ListenerTable oldTable = listenerMap.putIfAbsent(name, table);
+            if (oldTable != null)
+                table = oldTable;
+            NotificationListener identityListener =
+                    new IdentityListener(userListener);
+            synchronized (table) {
+                NotificationListener rewriteListener = null;
+                WeakReference<NotificationListener> wr =
+                        table.get(identityListener);
+                if (wr != null)
+                    rewriteListener = wr.get();
+                if (rewriteListener == null) {
+                    rewriteListener = new RewriteListener(
+                            name, userMBean, identityListener);
+                    wr = new WeakReference<NotificationListener>(rewriteListener);
+                    table.put(identityListener, wr);
+                }
+                return rewriteListener;
+            }
+        }
+
+        private DynamicMBean getMBean(ObjectName name)
+        throws InstanceNotFoundException {
+            DynamicMBean mbean = mbeans.get(name);
+            if (mbean == null)
+                throw new InstanceNotFoundException(name.toString());
+            return mbean;
+        }
+
+        private static interface WrapDynamicMBean extends DynamicMBean {
+            public Object getWrappedMBean();
+        }
+
+        private static class StandardWrapper
+                implements WrapDynamicMBean, MBeanRegistration {
+            private final Map<String, AttrMethods> attrMap = newMap();
+            private final Map<String, List<Method>> opMap = newMap();
+            private static class AttrMethods {
+                Method getter, setter;
+            }
+
+            private final Object std;
+
+            StandardWrapper(Object std) throws NotCompliantMBeanException {
+                this.std = std;
+                Class<?> intf = mbeanInterface(std.getClass());
+                try {
+                    initMaps(intf);
+                } catch (NotCompliantMBeanException e) {
+                    throw e;
+                } catch (Exception e) {
+                    NotCompliantMBeanException x =
+                            new NotCompliantMBeanException(e.getMessage());
+                    x.initCause(e);
+                    throw x;
+                }
+            }
+
+            private static Class<?> mbeanInterface(Class<?> c)
+            throws NotCompliantMBeanException {
+                do {
+                    Class<?>[] intfs = c.getInterfaces();
+                    String intfName = c.getName() + "MBean";
+                    for (Class<?> intf : intfs) {
+                        if (intf.getName().equals(intfName))
+                            return intf;
+                    }
+                    c = c.getSuperclass();
+                } while (c != null);
+                throw new NotCompliantMBeanException(
+                        "Does not match Standard or Dynamic MBean patterns: " +
+                        c.getName());
+            }
+
+            private void initMaps(Class<?> intf) throws NotCompliantMBeanException {
+                Method[] methods = intf.getMethods();
+
+                for (Method m : methods) {
+                    final String name = m.getName();
+                    final int nParams = m.getParameterTypes().length;
+
+                    String attrName = "";
+                    if (name.startsWith("get"))
+                        attrName = name.substring(3);
+                    else if (name.startsWith("is")
+                    && m.getReturnType() == boolean.class)
+                        attrName = name.substring(2);
+
+                    if (attrName.length() != 0 && m.getParameterTypes().length == 0
+                            && m.getReturnType() != void.class) {
+                        // It's a getter
+                        // Check we don't have both isX and getX
+                        AttrMethods am = attrMap.get(attrName);
+                        if (am == null)
+                            am = new AttrMethods();
+                        else {
+                            if (am.getter != null) {
+                                final String msg = "Attribute " + attrName +
+                                        " has more than one getter";
+                                throw new NotCompliantMBeanException(msg);
+                            }
+                        }
+                        am.getter = m;
+                        attrMap.put(attrName, am);
+                    } else if (name.startsWith("set") && name.length() > 3
+                            && m.getParameterTypes().length == 1 &&
+                            m.getReturnType() == void.class) {
+                        // It's a setter
+                        attrName = name.substring(3);
+                        AttrMethods am = attrMap.get(attrName);
+                        if (am == null)
+                            am = new AttrMethods();
+                        else if (am.setter != null) {
+                            final String msg = "Attribute " + attrName +
+                                    " has more than one setter";
+                            throw new NotCompliantMBeanException(msg);
+                        }
+                        am.setter = m;
+                        attrMap.put(attrName, am);
+                    } else {
+                        // It's an operation
+                        List<Method> ops = opMap.get(name);
+                        if (ops == null)
+                            ops = newList();
+                        ops.add(m);
+                        opMap.put(name, ops);
+                    }
+                }
+                /* Check that getters and setters are consistent. */
+                for (Map.Entry<String, AttrMethods> entry : attrMap.entrySet()) {
+                    AttrMethods am = entry.getValue();
+                    if (am.getter != null && am.setter != null &&
+                            am.getter.getReturnType() != am.setter.getParameterTypes()[0]) {
+                        final String msg = "Getter and setter for " + entry.getKey() +
+                                " have inconsistent types";
+                        throw new NotCompliantMBeanException(msg);
+                    }
+                }
+            }
+
+            public Object getAttribute(String attribute)
+            throws AttributeNotFoundException, MBeanException, ReflectionException {
+                AttrMethods am = attrMap.get(attribute);
+                if (am == null || am.getter == null)
+                    throw new AttributeNotFoundException(attribute);
+                return invokeMethod(am.getter);
+            }
+
+            public void setAttribute(Attribute attribute)
+            throws AttributeNotFoundException, InvalidAttributeValueException,
+                    MBeanException, ReflectionException {
+                String name = attribute.getName();
+                AttrMethods am = attrMap.get(name);
+                if (am == null || am.setter == null)
+                    throw new AttributeNotFoundException(name);
+                invokeMethod(am.setter, attribute.getValue());
+            }
+
+            public AttributeList getAttributes(String[] attributes) {
+                AttributeList list = new AttributeList();
+                for (String attr : attributes) {
+                    try {
+                        list.add(new Attribute(attr, getAttribute(attr)));
+                    } catch (Exception e) {
+                        // OK: ignore per spec
+                    }
+                }
+                return list;
+            }
+
+            public AttributeList setAttributes(AttributeList attributes) {
+                AttributeList list = new AttributeList();
+                // We carefully avoid using any new stuff from AttributeList here!
+                for (Iterator<?> it = attributes.iterator(); it.hasNext(); ) {
+                    Attribute attr = (Attribute) it.next();
+                    try {
+                        setAttribute(attr);
+                        list.add(attr);
+                    } catch (Exception e) {
+                        // OK: ignore per spec
+                    }
+                }
+                return list;
+            }
+
+            public Object invoke(String actionName, Object[] params, String[] signature)
+            throws MBeanException, ReflectionException {
+                if (params == null)
+                    params = new Object[0];
+                if (signature == null)
+                    signature = new String[0];
+                List<Method> methods = opMap.get(actionName);
+                if (methods == null) {
+                    Exception x = new NoSuchMethodException(actionName);
+                    throw new MBeanException(x);
+                }
+                Method found = null;
+                methodloop:
+                for (Method m : methods) {
+                    Class<?>[] msig = m.getParameterTypes();
+                    if (msig.length != signature.length)
+                        continue methodloop;
+                    for (int i = 0; i < msig.length; i++) {
+                        if (!msig[i].getName().equals(signature[i]))
+                            continue methodloop;
+                    }
+                    found = m;
+                    break methodloop;
+                }
+                if (found == null) {
+                    Exception x = new NoSuchMethodException(
+                            actionName + Arrays.toString(signature));
+                    throw new MBeanException(x);
+                }
+                return invokeMethod(found, params);
+            }
+
+            public MBeanInfo getMBeanInfo() {
+                // Attributes
+                List<MBeanAttributeInfo> attrs = newList();
+                for (Map.Entry<String, AttrMethods> attr : attrMap.entrySet()) {
+                    String name = attr.getKey();
+                    AttrMethods am = attr.getValue();
+                    try {
+                        attrs.add(new MBeanAttributeInfo(
+                                name, name, am.getter, am.setter));
+                    } catch (IntrospectionException e) { // grrr
+                        throw new RuntimeException(e);
+                    }
+                }
+
+                // Operations
+                List<MBeanOperationInfo> ops = newList();
+                for (Map.Entry<String, List<Method>> op : opMap.entrySet()) {
+                    String name = op.getKey();
+                    List<Method> methods = op.getValue();
+                    for (Method m : methods)
+                        ops.add(new MBeanOperationInfo(name, m));
+                }
+
+                // Constructors
+                List<MBeanConstructorInfo> constrs = newList();
+                for (Constructor constr : std.getClass().getConstructors())
+                    constrs.add(new MBeanConstructorInfo("Constructor", constr));
+
+                // Notifications
+                MBeanNotificationInfo[] notifs;
+                if (std instanceof NotificationBroadcaster)
+                    notifs = ((NotificationBroadcaster) std).getNotificationInfo();
+                else
+                    notifs = null;
+
+                String className = std.getClass().getName();
+                return new MBeanInfo(
+                        className, className,
+                        attrs.toArray(new MBeanAttributeInfo[0]),
+                        constrs.toArray(new MBeanConstructorInfo[0]),
+                        ops.toArray(new MBeanOperationInfo[0]),
+                        notifs);
+            }
+
+            private Object invokeMethod(Method m, Object... args)
+            throws MBeanException, ReflectionException {
+                return invokeSomething(m, std,args);
+            }
+
+            public ObjectName preRegister(MBeanServer server, ObjectName name)
+            throws Exception {
+                return mbeanRegistration(std).preRegister(server, name);
+            }
+
+            public void postRegister(Boolean registrationDone) {
+                mbeanRegistration(std).postRegister(registrationDone);
+            }
+
+            public void preDeregister() throws Exception {
+                mbeanRegistration(std).preDeregister();
+            }
+
+            public void postDeregister() {
+                mbeanRegistration(std).postDeregister();
+            }
+
+            public Object getWrappedMBean() {
+                return std;
+            }
+        }
+
+        private DynamicMBean standardToDynamic(Object std)
+        throws NotCompliantMBeanException {
+            return new StandardWrapper(std);
+        }
+
+//        private static class NotifWrapper
+//                implements WrapDynamicMBean, NotificationEmitter {
+//            private final DynamicMBean mbean;
+//
+//            NotifWrapper(DynamicMBean mbean) {
+//                this.mbean = mbean;
+//            }
+//
+//            public Object getAttribute(String attribute)
+//            throws AttributeNotFoundException, MBeanException, ReflectionException {
+//                return mbean.getAttribute(attribute);
+//            }
+//
+//            public void setAttribute(Attribute attribute)
+//            throws AttributeNotFoundException, InvalidAttributeValueException,
+//                    MBeanException, ReflectionException {
+//                mbean.setAttribute(attribute);
+//            }
+//
+//            public AttributeList getAttributes(String[] attributes) {
+//                return mbean.getAttributes(attributes);
+//            }
+//
+//            public AttributeList setAttributes(AttributeList attributes) {
+//                return mbean.setAttributes(attributes);
+//            }
+//
+//            public Object invoke(
+//                    String actionName, Object[] params, String[] signature)
+//                    throws MBeanException, ReflectionException {
+//                return mbean.invoke(actionName, params, signature);
+//            }
+//
+//            public MBeanInfo getMBeanInfo() {
+//                return mbean.getMBeanInfo();
+//            }
+//
+//            public void removeNotificationListener(
+//                    NotificationListener listener, NotificationFilter filter, Object handback)
+//            throws ListenerNotFoundException {
+//                ((NotificationEmitter) mbean).removeNotificationListener(
+//                        listener, filter, handback);
+//                // ClassCastException if MBean is not an emitter
+//            }
+//
+//            public void addNotificationListener(
+//                    NotificationListener listener, NotificationFilter filter, Object handback)
+//            throws IllegalArgumentException {
+//                ((NotificationBroadcaster) mbean).addNotificationListener(
+//                        listener, filter, handback);
+//            }
+//
+//            public void removeNotificationListener(NotificationListener listener)
+//            throws ListenerNotFoundException {
+//                ((NotificationBroadcaster) mbean).removeNotificationListener(listener);
+//            }
+//
+//            public MBeanNotificationInfo[] getNotificationInfo() {
+//                return ((NotificationBroadcaster) mbean).getNotificationInfo();
+//            }
+//
+//            public Object getWrappedMBean() {
+//                return getUserMBean(mbean);
+//            }
+//        }
+
+        private static Object invokeSomething(
+                AccessibleObject ao, Object target, Object[] args)
+        throws MBeanException, ReflectionException {
+            try {
+                if (ao instanceof Method)
+                    return ((Method) ao).invoke(target, args);
+                else
+                    return ((Constructor) ao).newInstance(args);
+            } catch (InvocationTargetException e) {
+                try {
+                    throw e.getCause();
+                } catch (RuntimeException x) {
+                    throw new RuntimeMBeanException(x);
+                } catch (Error x) {
+                    throw new RuntimeErrorException(x);
+                } catch (Exception x) {
+                    throw new MBeanException(x);
+                } catch (Throwable x) {
+                    throw new RuntimeException(x); // neither Error nor Exception!
+                }
+            } catch (Exception e) {
+                throw new ReflectionException(e);
+            }
+        }
+
+        private static Object getUserMBean(DynamicMBean mbean) {
+            if (mbean instanceof WrapDynamicMBean)
+                return ((WrapDynamicMBean) mbean).getWrappedMBean();
+            return mbean;
+        }
+
+        private Object getUserMBean(ObjectName name)
+        throws InstanceNotFoundException {
+            return getUserMBean(getMBean(name));
+        }
+
+        private static final MBeanRegistration noRegistration =
+                new MBeanRegistration() {
+            public ObjectName preRegister(MBeanServer server, ObjectName name) {
+                return name;
+            }
+
+            public void postRegister(Boolean registrationDone) {
+            }
+
+            public void preDeregister() throws Exception {
+            }
+
+            public void postDeregister() {
+            }
+        };
+
+        private static MBeanRegistration mbeanRegistration(Object object) {
+            if (object instanceof MBeanRegistration)
+                return (MBeanRegistration) object;
+            else
+                return noRegistration;
+        }
+
+        private static <E> List<E> newList() {
+            return new ArrayList<E>();
+        }
+
+        private static <K, V> Map<K, V> newMap() {
+            return new HashMap<K, V>();
+        }
+
+        private static <E> Set<E> newSet() {
+            return new HashSet<E>();
+        }
+    }
+}