jdk/src/share/classes/javax/management/remote/JMXConnectorServer.java
changeset 2 90ce3da70b43
child 1004 5ba8217eb504
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/management/remote/JMXConnectorServer.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,412 @@
+/*
+ * Copyright 2003-2007 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.  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 javax.management.remote;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import javax.management.MBeanNotificationInfo;
+import javax.management.MBeanRegistration;
+import javax.management.MBeanServer;
+import javax.management.Notification;
+import javax.management.NotificationBroadcasterSupport;
+import javax.management.ObjectName;
+
+/**
+ * <p>Superclass of every connector server.  A connector server is
+ * attached to an MBean server.  It listens for client connection
+ * requests and creates a connection for each one.</p>
+ *
+ * <p>A connector server is associated with an MBean server either by
+ * registering it in that MBean server, or by passing the MBean server
+ * to its constructor.</p>
+ *
+ * <p>A connector server is inactive when created.  It only starts
+ * listening for client connections when the {@link #start() start}
+ * method is called.  A connector server stops listening for client
+ * connections when the {@link #stop() stop} method is called or when
+ * the connector server is unregistered from its MBean server.</p>
+ *
+ * <p>Stopping a connector server does not unregister it from its
+ * MBean server.  A connector server once stopped cannot be
+ * restarted.</p>
+ *
+ * <p>Each time a client connection is made or broken, a notification
+ * of class {@link JMXConnectionNotification} is emitted.</p>
+ *
+ * @since 1.5
+ */
+public abstract class JMXConnectorServer
+        extends NotificationBroadcasterSupport
+        implements JMXConnectorServerMBean, MBeanRegistration, JMXAddressable {
+
+    /**
+     * <p>Name of the attribute that specifies the authenticator for a
+     * connector server.  The value associated with this attribute, if
+     * any, must be an object that implements the interface {@link
+     * JMXAuthenticator}.</p>
+     */
+    public static final String AUTHENTICATOR =
+        "jmx.remote.authenticator";
+
+    /**
+     * <p>Constructs a connector server that will be registered as an
+     * MBean in the MBean server it is attached to.  This constructor
+     * is typically called by one of the <code>createMBean</code>
+     * methods when creating, within an MBean server, a connector
+     * server that makes it available remotely.</p>
+     */
+    public JMXConnectorServer() {
+        this(null);
+    }
+
+    /**
+     * <p>Constructs a connector server that is attached to the given
+     * MBean server.  A connector server that is created in this way
+     * can be registered in a different MBean server.</p>
+     *
+     * @param mbeanServer the MBean server that this connector server
+     * is attached to.  Null if this connector server will be attached
+     * to an MBean server by being registered in it.
+     */
+    public JMXConnectorServer(MBeanServer mbeanServer) {
+        this.mbeanServer = mbeanServer;
+    }
+
+    /**
+     * <p>Returns the MBean server that this connector server is
+     * attached to.</p>
+     *
+     * @return the MBean server that this connector server is attached
+     * to, or null if it is not yet attached to an MBean server.
+     */
+    public synchronized MBeanServer getMBeanServer() {
+        return mbeanServer;
+    }
+
+    public synchronized void setMBeanServerForwarder(MBeanServerForwarder mbsf)
+    {
+        if (mbsf == null)
+            throw new IllegalArgumentException("Invalid null argument: mbsf");
+
+        if (mbeanServer !=  null) mbsf.setMBeanServer(mbeanServer);
+        mbeanServer = mbsf;
+    }
+
+    public String[] getConnectionIds() {
+        synchronized (connectionIds) {
+            return connectionIds.toArray(new String[connectionIds.size()]);
+        }
+    }
+
+    /**
+     * <p>Returns a client stub for this connector server.  A client
+     * stub is a serializable object whose {@link
+     * JMXConnector#connect(Map) connect} method can be used to make
+     * one new connection to this connector server.</p>
+     *
+     * <p>A given connector need not support the generation of client
+     * stubs.  However, the connectors specified by the JMX Remote API do
+     * (JMXMP Connector and RMI Connector).</p>
+     *
+     * <p>The default implementation of this method uses {@link
+     * #getAddress} and {@link JMXConnectorFactory} to generate the
+     * stub, with code equivalent to the following:</p>
+     *
+     * <pre>
+     * JMXServiceURL addr = {@link #getAddress() getAddress()};
+     * return {@link JMXConnectorFactory#newJMXConnector(JMXServiceURL, Map)
+     *          JMXConnectorFactory.newJMXConnector(addr, env)};
+     * </pre>
+     *
+     * <p>A connector server for which this is inappropriate must
+     * override this method so that it either implements the
+     * appropriate logic or throws {@link
+     * UnsupportedOperationException}.</p>
+     *
+     * @param env client connection parameters of the same sort that
+     * could be provided to {@link JMXConnector#connect(Map)
+     * JMXConnector.connect(Map)}.  Can be null, which is equivalent
+     * to an empty map.
+     *
+     * @return a client stub that can be used to make a new connection
+     * to this connector server.
+     *
+     * @exception UnsupportedOperationException if this connector
+     * server does not support the generation of client stubs.
+     *
+     * @exception IllegalStateException if the JMXConnectorServer is
+     * not started (see {@link JMXConnectorServerMBean#isActive()}).
+     *
+     * @exception IOException if a communications problem means that a
+     * stub cannot be created.
+     **/
+    public JMXConnector toJMXConnector(Map<String,?> env)
+        throws IOException
+    {
+        if (!isActive()) throw new
+            IllegalStateException("Connector is not active");
+        JMXServiceURL addr = getAddress();
+        return JMXConnectorFactory.newJMXConnector(addr, env);
+    }
+
+    /**
+     * <p>Returns an array indicating the notifications that this MBean
+     * sends. The implementation in <code>JMXConnectorServer</code>
+     * returns an array with one element, indicating that it can emit
+     * notifications of class {@link JMXConnectionNotification} with
+     * the types defined in that class.  A subclass that can emit other
+     * notifications should return an array that contains this element
+     * plus descriptions of the other notifications.</p>
+     *
+     * @return the array of possible notifications.
+     */
+    public MBeanNotificationInfo[] getNotificationInfo() {
+        final String[] types = {
+            JMXConnectionNotification.OPENED,
+            JMXConnectionNotification.CLOSED,
+            JMXConnectionNotification.FAILED,
+        };
+        final String className = JMXConnectionNotification.class.getName();
+        final String description =
+            "A client connection has been opened or closed";
+        return new MBeanNotificationInfo[] {
+            new MBeanNotificationInfo(types, className, description),
+        };
+    }
+
+    /**
+     * <p>Called by a subclass when a new client connection is opened.
+     * Adds <code>connectionId</code> to the list returned by {@link
+     * #getConnectionIds()}, then emits a {@link
+     * JMXConnectionNotification} with type {@link
+     * JMXConnectionNotification#OPENED}.</p>
+     *
+     * @param connectionId the ID of the new connection.  This must be
+     * different from the ID of any connection previously opened by
+     * this connector server.
+     *
+     * @param message the message for the emitted {@link
+     * JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getMessage()}.
+     *
+     * @param userData the <code>userData</code> for the emitted
+     * {@link JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getUserData()}.
+     *
+     * @exception NullPointerException if <code>connectionId</code> is
+     * null.
+     */
+    protected void connectionOpened(String connectionId,
+                                    String message,
+                                    Object userData) {
+
+        if (connectionId == null)
+            throw new NullPointerException("Illegal null argument");
+
+        synchronized (connectionIds) {
+            connectionIds.add(connectionId);
+        }
+
+        sendNotification(JMXConnectionNotification.OPENED, connectionId,
+                         message, userData);
+    }
+
+    /**
+     * <p>Called by a subclass when a client connection is closed
+     * normally.  Removes <code>connectionId</code> from the list returned
+     * by {@link #getConnectionIds()}, then emits a {@link
+     * JMXConnectionNotification} with type {@link
+     * JMXConnectionNotification#CLOSED}.</p>
+     *
+     * @param connectionId the ID of the closed connection.
+     *
+     * @param message the message for the emitted {@link
+     * JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getMessage()}.
+     *
+     * @param userData the <code>userData</code> for the emitted
+     * {@link JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getUserData()}.
+     *
+     * @exception NullPointerException if <code>connectionId</code>
+     * is null.
+     */
+    protected void connectionClosed(String connectionId,
+                                    String message,
+                                    Object userData) {
+
+        if (connectionId == null)
+            throw new NullPointerException("Illegal null argument");
+
+        synchronized (connectionIds) {
+            connectionIds.remove(connectionId);
+        }
+
+        sendNotification(JMXConnectionNotification.CLOSED, connectionId,
+                         message, userData);
+    }
+
+    /**
+     * <p>Called by a subclass when a client connection fails.
+     * Removes <code>connectionId</code> from the list returned by
+     * {@link #getConnectionIds()}, then emits a {@link
+     * JMXConnectionNotification} with type {@link
+     * JMXConnectionNotification#FAILED}.</p>
+     *
+     * @param connectionId the ID of the failed connection.
+     *
+     * @param message the message for the emitted {@link
+     * JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getMessage()}.
+     *
+     * @param userData the <code>userData</code> for the emitted
+     * {@link JMXConnectionNotification}.  Can be null.  See {@link
+     * Notification#getUserData()}.
+     *
+     * @exception NullPointerException if <code>connectionId</code> is
+     * null.
+     */
+    protected void connectionFailed(String connectionId,
+                                    String message,
+                                    Object userData) {
+
+        if (connectionId == null)
+            throw new NullPointerException("Illegal null argument");
+
+        synchronized (connectionIds) {
+            connectionIds.remove(connectionId);
+        }
+
+        sendNotification(JMXConnectionNotification.FAILED, connectionId,
+                         message, userData);
+    }
+
+    private void sendNotification(String type, String connectionId,
+                                  String message, Object userData) {
+        Notification notif =
+            new JMXConnectionNotification(type,
+                                          getNotificationSource(),
+                                          connectionId,
+                                          nextSequenceNumber(),
+                                          message,
+                                          userData);
+        sendNotification(notif);
+    }
+
+    private synchronized Object getNotificationSource() {
+        if (myName != null)
+            return myName;
+        else
+            return this;
+    }
+
+    private static long nextSequenceNumber() {
+        synchronized (sequenceNumberLock) {
+            return sequenceNumber++;
+        }
+    }
+
+    // implements MBeanRegistration
+    /**
+     * <p>Called by an MBean server when this connector server is
+     * registered in that MBean server.  This connector server becomes
+     * attached to the MBean server and its {@link #getMBeanServer()}
+     * method will return <code>mbs</code>.</p>
+     *
+     * <p>If this connector server is already attached to an MBean
+     * server, this method has no effect.  The MBean server it is
+     * attached to is not necessarily the one it is being registered
+     * in.</p>
+     *
+     * @param mbs the MBean server in which this connection server is
+     * being registered.
+     *
+     * @param name The object name of the MBean.
+     *
+     * @return The name under which the MBean is to be registered.
+     *
+     * @exception NullPointerException if <code>mbs</code> or
+     * <code>name</code> is null.
+     */
+    public synchronized ObjectName preRegister(MBeanServer mbs,
+                                               ObjectName name) {
+        if (mbs == null || name == null)
+            throw new NullPointerException("Null MBeanServer or ObjectName");
+        if (mbeanServer == null) {
+            mbeanServer = mbs;
+            myName = name;
+        }
+        return name;
+    }
+
+    public void postRegister(Boolean registrationDone) {
+        // do nothing
+    }
+
+    /**
+     * <p>Called by an MBean server when this connector server is
+     * unregistered from that MBean server.  If this connector server
+     * was attached to that MBean server by being registered in it,
+     * and if the connector server is still active,
+     * then unregistering it will call the {@link #stop stop} method.
+     * If the <code>stop</code> method throws an exception, the
+     * unregistration attempt will fail.  It is recommended to call
+     * the <code>stop</code> method explicitly before unregistering
+     * the MBean.</p>
+     *
+     * @exception IOException if thrown by the {@link #stop stop} method.
+     */
+    public synchronized void preDeregister() throws Exception {
+        if (myName != null && isActive()) {
+            stop();
+            myName = null; // just in case stop is buggy and doesn't stop
+        }
+    }
+
+    public void postDeregister() {
+        myName = null;
+    }
+
+    /**
+     * The MBeanServer used by this server to execute a client request.
+     */
+    private MBeanServer mbeanServer = null;
+
+    /**
+     * The name used to registered this server in an MBeanServer.
+     * It is null if the this server is not registered or has been unregistered.
+     */
+    private ObjectName myName;
+
+    private List<String> connectionIds = new ArrayList<String>();
+
+    private static final int[] sequenceNumberLock = new int[0];
+    private static long sequenceNumber;
+}