jdk/src/share/classes/com/sun/jmx/interceptor/DispatchInterceptor.java
changeset 1156 bbc2d15aaf7a
child 1222 78e3d021d528
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/com/sun/jmx/interceptor/DispatchInterceptor.java	Thu Sep 04 14:46:36 2008 +0200
@@ -0,0 +1,547 @@
+/*
+ * Copyright 2008 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package com.sun.jmx.interceptor;
+
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
+
+import javax.management.Attribute;
+import javax.management.AttributeList;
+import javax.management.AttributeNotFoundException;
+import javax.management.InstanceAlreadyExistsException;
+import javax.management.InstanceNotFoundException;
+import javax.management.IntrospectionException;
+import javax.management.InvalidAttributeValueException;
+import javax.management.ListenerNotFoundException;
+import javax.management.MBeanException;
+import javax.management.MBeanInfo;
+import javax.management.MBeanRegistrationException;
+import javax.management.MBeanServer;
+import javax.management.MalformedObjectNameException;
+import javax.management.NotCompliantMBeanException;
+import javax.management.NotificationFilter;
+import javax.management.NotificationListener;
+import javax.management.ObjectInstance;
+import javax.management.ObjectName;
+import javax.management.QueryExp;
+import javax.management.ReflectionException;
+import javax.management.namespace.JMXNamespace;
+
+/**
+ * A dispatcher that dispatches to MBeanServers.
+ * <p><b>
+ * This API is a Sun internal API and is subject to changes without notice.
+ * </b></p>
+ * @since 1.7
+ */
+//
+// This is the base class for implementing dispatchers. We have two concrete
+// dispatcher implementations:
+//
+//   * A NamespaceDispatchInterceptor, which dispatch calls to existing
+//     namespace interceptors
+//   * A DomainDispatchInterceptor, which dispatch calls to existing domain
+//     interceptors.
+//
+// With the JMX Namespaces feature, the JMX MBeanServer is now structured
+// as follows:
+//
+// The JMX MBeanServer delegates to a NamespaceDispatchInterceptor,
+// which either dispatches to a namespace, or delegates to the
+// DomainDispatchInterceptor (if the object name contained no namespace).
+// The DomainDispatchInterceptor in turn either dispatches to a domain (if
+// there is a JMXDomain for that domain) or delegates to the
+// DefaultMBeanServerInterceptor (if there is no JMXDomain for that
+// domain). This makes the following picture:
+//
+//             JMX MBeanServer (outer shell)
+//                          |
+//                          |
+//              NamespaceDispatchInterceptor
+//                   /               \
+//     no namespace in object name?   \
+//                 /                   \
+//                /                   dispatch to namespace
+//         DomainDispatchInterceptor
+//              /              \
+//    no JMXDomain for domain?  \
+//            /                  \
+//           /                   dispatch to domain
+//  DefaultMBeanServerInterceptor
+//         /
+//   invoke locally registered MBean
+//
+//  The logic for maintaining a map of interceptors
+//  and dispatching to impacted interceptor, is implemented in this
+//  base class, which both NamespaceDispatchInterceptor and
+//  DomainDispatchInterceptor extend.
+//
+public abstract class DispatchInterceptor
+        <T extends MBeanServer, N extends JMXNamespace>
+        extends MBeanServerInterceptorSupport {
+
+    /**
+     * This is an abstraction which allows us to handle queryNames
+     * and queryMBeans with the same algorithm. There are some subclasses
+     * where we need to override both queryNames & queryMBeans to apply
+     * the same transformation (usually aggregation of results when
+     * several namespaces/domains are impacted) to both algorithms.
+     * Usually the only thing that varies between the algorithm of
+     * queryNames & the algorithm of queryMBean is the type of objects
+     * in the returned Set. By using a QueryInvoker we can implement the
+     * transformation only once and apply it to both queryNames &
+     * queryMBeans.
+     * @see QueryInterceptor below, and its subclass in
+     * {@link DomainDispatcher}.
+     **/
+    static abstract class QueryInvoker<T> {
+        abstract Set<T> query(MBeanServer mbs,
+                        ObjectName pattern, QueryExp query);
+    }
+
+    /**
+     * Used to perform queryNames. A QueryInvoker that invokes
+     * queryNames on an MBeanServer.
+     **/
+    final static QueryInvoker<ObjectName> queryNamesInvoker =
+            new QueryInvoker<ObjectName>() {
+        Set<ObjectName> query(MBeanServer mbs,
+                        ObjectName pattern, QueryExp query) {
+            return mbs.queryNames(pattern,query);
+        }
+    };
+
+    /**
+     * Used to perform queryMBeans. A QueryInvoker that invokes
+     * queryMBeans on an MBeanServer.
+     **/
+    final static QueryInvoker<ObjectInstance> queryMBeansInvoker =
+            new QueryInvoker<ObjectInstance>() {
+        Set<ObjectInstance> query(MBeanServer mbs,
+                        ObjectName pattern, QueryExp query) {
+            return mbs.queryMBeans(pattern,query);
+        }
+    };
+
+    /**
+     * We use this class to intercept queries.
+     * There's a special case for JMXNamespace MBeans, because
+     * "namespace//*:*" matches both "namespace//domain:k=v" and
+     * "namespace//:type=JMXNamespace".
+     * Therefore, queries may need to be forwarded to more than
+     * on interceptor and the results aggregated...
+     */
+     static class QueryInterceptor {
+        final MBeanServer wrapped;
+        QueryInterceptor(MBeanServer mbs) {
+            wrapped = mbs;
+        }
+        <X> Set<X> query(ObjectName pattern, QueryExp query,
+                QueryInvoker<X> invoker, MBeanServer server) {
+            return invoker.query(server, pattern, query);
+        }
+
+        public Set<ObjectName> queryNames(ObjectName pattern, QueryExp query) {
+            return query(pattern,query,queryNamesInvoker,wrapped);
+        }
+
+        public Set<ObjectInstance> queryMBeans(ObjectName pattern,
+                QueryExp query) {
+            return query(pattern,query,queryMBeansInvoker,wrapped);
+        }
+    }
+
+    // We don't need a ConcurrentHashMap here because getkeys() returns
+    // an array of keys. Therefore there's no risk to have a
+    // ConcurrentModificationException. We must however take into
+    // account the fact that there can be no interceptor for
+    // some of the returned keys if the map is being modified by
+    // another thread, or by a callback within the same thread...
+    // See getKeys() in this class and query() in DomainDispatcher.
+    //
+    private final Map<String,T> handlerMap =
+            Collections.synchronizedMap(
+            new HashMap<String,T>());
+
+    // The key at which an interceptor for accessing the named MBean can be
+    // found in the handlerMap. Note: there doesn't need to be an interceptor
+    // for that key in the Map.
+    //
+    public abstract String getHandlerKey(ObjectName name);
+
+    // Returns an interceptor for that name, or null if there's no interceptor
+    // for that name.
+    abstract MBeanServer getInterceptorOrNullFor(ObjectName name);
+
+    // Returns a QueryInterceptor for that pattern.
+    abstract QueryInterceptor getInterceptorForQuery(ObjectName pattern);
+
+    // Returns the ObjectName of the JMXNamespace (or JMXDomain) for that
+    // key (a namespace or a domain name).
+    abstract ObjectName getHandlerNameFor(String key)
+        throws MalformedObjectNameException;
+
+    // Creates an interceptor for the given key, name, JMXNamespace (or
+    // JMXDomain). Note: this will be either a NamespaceInterceptor
+    // wrapping a JMXNamespace, if this object is an instance of
+    // NamespaceDispatchInterceptor, or a DomainInterceptor wrapping a
+    // JMXDomain, if this object is an instance of DomainDispatchInterceptor.
+    abstract T createInterceptorFor(String key, ObjectName name,
+            N jmxNamespace, Queue<Runnable> postRegisterQueue);
+    //
+    // The next interceptor in the chain.
+    //
+    // For the NamespaceDispatchInterceptor, this the DomainDispatchInterceptor.
+    // For the DomainDispatchInterceptor, this is the
+    // DefaultMBeanServerInterceptor.
+    //
+    // The logic of when to invoke the next interceptor in the chain depends
+    // on the logic of the concrete dispatcher class.
+    //
+    // For instance, the NamespaceDispatchInterceptor invokes the next
+    // interceptor when the object name doesn't contain any namespace.
+    //
+    // On the other hand, the DomainDispatchInterceptor invokes the
+    // next interceptor when there's no interceptor for the accessed domain.
+    //
+    abstract MBeanServer getNextInterceptor();
+
+    // hook for cleanup in subclasses.
+    void interceptorReleased(T interceptor,
+            Queue<Runnable> postDeregisterQueue) {
+        // hook
+    }
+
+    // Hook for subclasses.
+    MBeanServer getInterceptorForCreate(ObjectName name)
+        throws MBeanRegistrationException {
+        final MBeanServer ns = getInterceptorOrNullFor(name);
+        if (ns == null) // name cannot be null here.
+            throw new MBeanRegistrationException(
+                    new IllegalArgumentException("No such MBean handler: " +
+                        getHandlerKey(name) + " for " +name));
+        return ns;
+    }
+
+    // Hook for subclasses.
+    MBeanServer getInterceptorForInstance(ObjectName name)
+        throws InstanceNotFoundException {
+        final MBeanServer ns = getInterceptorOrNullFor(name);
+        if (ns == null) // name cannot be null here.
+            throw new InstanceNotFoundException(String.valueOf(name));
+        return ns;
+    }
+
+    // sanity checks
+    void validateHandlerNameFor(String key, ObjectName name) {
+        if (key == null || key.equals(""))
+            throw new IllegalArgumentException("invalid key for "+name+": "+key);
+        try {
+            final ObjectName handlerName = getHandlerNameFor(key);
+            if (!name.equals(handlerName))
+                throw new IllegalArgumentException("bad handler name: "+name+
+                        ". Should be: "+handlerName);
+        } catch (MalformedObjectNameException x) {
+            throw new IllegalArgumentException(name.toString(),x);
+        }
+    }
+
+    // Called by the DefaultMBeanServerInterceptor when an instance
+    // of JMXNamespace (or a subclass of it) is registered as an MBean.
+    // This method is usually invoked from within the repository lock,
+    // hence the necessity of the postRegisterQueue.
+    public void addNamespace(ObjectName name, N jmxNamespace,
+            Queue<Runnable> postRegisterQueue) {
+        final String key = getHandlerKey(name);
+        validateHandlerNameFor(key,name);
+        synchronized (handlerMap) {
+            final T exists =
+                    handlerMap.get(key);
+            if (exists != null)
+                throw new IllegalArgumentException(key+
+                        ": handler already exists");
+
+            final T ns = createInterceptorFor(key,name,jmxNamespace,
+                    postRegisterQueue);
+            handlerMap.put(key,ns);
+        }
+    }
+
+    // Called by the DefaultMBeanServerInterceptor when an instance
+    // of JMXNamespace (or a subclass of it) is deregistered.
+    // This method is usually invoked from within the repository lock,
+    // hence the necessity of the postDeregisterQueue.
+    public void removeNamespace(ObjectName name, N jmxNamespace,
+            Queue<Runnable> postDeregisterQueue) {
+        final String key = getHandlerKey(name);
+        final T ns;
+        synchronized(handlerMap) {
+            ns = handlerMap.remove(key);
+        }
+        interceptorReleased(ns,postDeregisterQueue);
+    }
+
+    // Get the interceptor for that key.
+    T getInterceptor(String key) {
+        synchronized (handlerMap) {
+            return handlerMap.get(key);
+        }
+    }
+
+    // We return an array of keys, which makes it possible to make
+    // concurrent modifications of the handlerMap, provided that
+    // the code which loops over the keys is prepared to handle null
+    // interceptors.
+    // See declaration of handlerMap above, and see also query() in
+    // DomainDispatcher
+    //
+    public String[] getKeys() {
+        synchronized (handlerMap) {
+            final int size = handlerMap.size();
+            return handlerMap.keySet().toArray(new String[size]);
+        }
+    }
+
+    // From MBeanServer
+    public ObjectInstance createMBean(String className, ObjectName name)
+            throws ReflectionException, InstanceAlreadyExistsException,
+                   MBeanRegistrationException, MBeanException,
+                   NotCompliantMBeanException {
+        return getInterceptorForCreate(name).createMBean(className,name);
+    }
+
+    // From MBeanServer
+    public ObjectInstance createMBean(String className, ObjectName name,
+                                      ObjectName loaderName)
+            throws ReflectionException, InstanceAlreadyExistsException,
+                   MBeanRegistrationException, MBeanException,
+                   NotCompliantMBeanException, InstanceNotFoundException{
+        return getInterceptorForCreate(name).createMBean(className,name,loaderName);
+    }
+
+    // From MBeanServer
+    public ObjectInstance createMBean(String className, ObjectName name,
+                                      Object params[], String signature[])
+            throws ReflectionException, InstanceAlreadyExistsException,
+                   MBeanRegistrationException, MBeanException,
+                   NotCompliantMBeanException{
+        return getInterceptorForCreate(name).
+                createMBean(className,name,params,signature);
+    }
+
+    // From MBeanServer
+    public ObjectInstance createMBean(String className, ObjectName name,
+                                      ObjectName loaderName, Object params[],
+                                      String signature[])
+            throws ReflectionException, InstanceAlreadyExistsException,
+                   MBeanRegistrationException, MBeanException,
+                   NotCompliantMBeanException, InstanceNotFoundException{
+        return getInterceptorForCreate(name).createMBean(className,name,loaderName,
+                                                   params,signature);
+    }
+
+    // From MBeanServer
+    public ObjectInstance registerMBean(Object object, ObjectName name)
+            throws InstanceAlreadyExistsException, MBeanRegistrationException,
+                   NotCompliantMBeanException {
+        return getInterceptorForCreate(name).registerMBean(object,name);
+    }
+
+    // From MBeanServer
+    public void unregisterMBean(ObjectName name)
+            throws InstanceNotFoundException, MBeanRegistrationException {
+        getInterceptorForInstance(name).unregisterMBean(name);
+    }
+
+    // From MBeanServer
+    public ObjectInstance getObjectInstance(ObjectName name)
+            throws InstanceNotFoundException {
+        return getInterceptorForInstance(name).getObjectInstance(name);
+    }
+
+    // From MBeanServer
+    public Set<ObjectInstance> queryMBeans(ObjectName name, QueryExp query) {
+        final QueryInterceptor mbs =
+                getInterceptorForQuery(name);
+        if (mbs == null)  return Collections.emptySet();
+        else return mbs.queryMBeans(name,query);
+    }
+
+    // From MBeanServer
+    public Set<ObjectName> queryNames(ObjectName name, QueryExp query) {
+        final QueryInterceptor mbs =
+                getInterceptorForQuery(name);
+        if (mbs == null)  return Collections.emptySet();
+        else return mbs.queryNames(name,query);
+    }
+
+    // From MBeanServer
+    public boolean isRegistered(ObjectName name) {
+        final MBeanServer mbs = getInterceptorOrNullFor(name);
+        if (mbs == null) return false;
+        else return mbs.isRegistered(name);
+    }
+
+    // From MBeanServer
+    public Integer getMBeanCount() {
+        return getNextInterceptor().getMBeanCount();
+    }
+
+    // From MBeanServer
+    public Object getAttribute(ObjectName name, String attribute)
+            throws MBeanException, AttributeNotFoundException,
+                   InstanceNotFoundException, ReflectionException {
+        return getInterceptorForInstance(name).getAttribute(name,attribute);
+    }
+
+    // From MBeanServer
+    public AttributeList getAttributes(ObjectName name, String[] attributes)
+            throws InstanceNotFoundException, ReflectionException {
+        return getInterceptorForInstance(name).getAttributes(name,attributes);
+    }
+
+    // From MBeanServer
+    public void setAttribute(ObjectName name, Attribute attribute)
+            throws InstanceNotFoundException, AttributeNotFoundException,
+                   InvalidAttributeValueException, MBeanException,
+                   ReflectionException {
+        getInterceptorForInstance(name).setAttribute(name,attribute);
+    }
+
+    // From MBeanServer
+    public AttributeList setAttributes(ObjectName name,
+                                       AttributeList attributes)
+        throws InstanceNotFoundException, ReflectionException {
+        return getInterceptorForInstance(name).setAttributes(name,attributes);
+    }
+
+    // From MBeanServer
+    public Object invoke(ObjectName name, String operationName,
+                         Object params[], String signature[])
+            throws InstanceNotFoundException, MBeanException,
+                   ReflectionException {
+        return getInterceptorForInstance(name).invoke(name,operationName,params,
+                signature);
+    }
+
+    // From MBeanServer
+    public String getDefaultDomain() {
+        return getNextInterceptor().getDefaultDomain();
+    }
+
+    /**
+     * Returns the list of domains in which any MBean is currently
+     * registered.
+     */
+    public abstract String[] getDomains();
+
+    // From MBeanServer
+    public void addNotificationListener(ObjectName name,
+                                        NotificationListener listener,
+                                        NotificationFilter filter,
+                                        Object handback)
+            throws InstanceNotFoundException {
+        getInterceptorForInstance(name).addNotificationListener(name,listener,filter,
+                handback);
+    }
+
+
+    // From MBeanServer
+    public void addNotificationListener(ObjectName name,
+                                        ObjectName listener,
+                                        NotificationFilter filter,
+                                        Object handback)
+            throws InstanceNotFoundException {
+        getInterceptorForInstance(name).addNotificationListener(name,listener,filter,
+                handback);
+    }
+
+    // From MBeanServer
+    public void removeNotificationListener(ObjectName name,
+                                           ObjectName listener)
+        throws InstanceNotFoundException, ListenerNotFoundException {
+        getInterceptorForInstance(name).removeNotificationListener(name,listener);
+    }
+
+    // From MBeanServer
+    public void removeNotificationListener(ObjectName name,
+                                           ObjectName listener,
+                                           NotificationFilter filter,
+                                           Object handback)
+            throws InstanceNotFoundException, ListenerNotFoundException {
+        getInterceptorForInstance(name).removeNotificationListener(name,listener,filter,
+                handback);
+    }
+
+
+    // From MBeanServer
+    public void removeNotificationListener(ObjectName name,
+                                           NotificationListener listener)
+            throws InstanceNotFoundException, ListenerNotFoundException {
+        getInterceptorForInstance(name).removeNotificationListener(name,listener);
+    }
+
+    // From MBeanServer
+    public void removeNotificationListener(ObjectName name,
+                                           NotificationListener listener,
+                                           NotificationFilter filter,
+                                           Object handback)
+            throws InstanceNotFoundException, ListenerNotFoundException {
+        getInterceptorForInstance(name).removeNotificationListener(name,listener,filter,
+                handback);
+    }
+
+    // From MBeanServer
+    public MBeanInfo getMBeanInfo(ObjectName name)
+            throws InstanceNotFoundException, IntrospectionException,
+                   ReflectionException {
+        return getInterceptorForInstance(name).getMBeanInfo(name);
+    }
+
+
+    // From MBeanServer
+    public boolean isInstanceOf(ObjectName name, String className)
+            throws InstanceNotFoundException {
+        return getInterceptorForInstance(name).isInstanceOf(name,className);
+    }
+
+    // From MBeanServer
+    public ClassLoader getClassLoaderFor(ObjectName mbeanName)
+        throws InstanceNotFoundException {
+        return getInterceptorForInstance(mbeanName).getClassLoaderFor(mbeanName);
+    }
+
+    // From MBeanServer
+    public ClassLoader getClassLoader(ObjectName loaderName)
+        throws InstanceNotFoundException {
+        return getInterceptorForInstance(loaderName).getClassLoader(loaderName);
+    }
+
+}