/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.mx.interceptor;
import java.util.Hashtable;
import java.util.Set;
import javax.management.InstanceAlreadyExistsException;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;
import javax.management.MBeanServer;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import javax.management.modelmbean.ModelMBean;
import javax.management.modelmbean.ModelMBeanInfo;
import javax.management.modelmbean.ModelMBeanInfoSupport;
import javax.management.modelmbean.ModelMBeanOperationInfo;
import org.jboss.logging.Logger;
import org.jboss.mx.modelmbean.ModelMBeanConstants;
import org.jboss.mx.modelmbean.RequiredModelMBeanInstantiator;
import org.jboss.mx.server.Invocation;
import org.jboss.mx.service.ServiceConstants;
import org.jboss.mx.util.AgentID;
/**
* Base class for shared interceptors. This class provides some default method
* implementations for shared interceptors.
*
* @see org.jboss.mx.interceptor.SharedInterceptor
* @see org.jboss.mx.server.MBeanInvoker
*
* @author <a href="mailto:juha@jboss.org">Juha Lindfors</a>.
* @version $Revision: 81026 $
*/
public abstract class AbstractSharedInterceptor
extends AbstractInterceptor
implements SharedInterceptor
{
/**
* MBean server reference for shared interceptors.
*/
protected MBeanServer server = null;
/**
* Object name of this interceptor. Shared interceptors must always contain
* a valid object name.
*/
protected ObjectName objectName = null;
// Constructors --------------------------------------------------
/**
* Constructs a new shared interceptor instance. The interceptor is not
* automatically registered to the MBean server. Notice that the interceptor
* name must be set before the call to {@link #register} method. Shared
* interceptor names must be unique within the MBean server.
*/
public AbstractSharedInterceptor() {}
/**
* Constructs a new shared interceptor instance with a given name. The interceptor
* is not automatically registered to the MBean server. Notice that the
* shared interceptor name must be unique name among all shared interceptors
* within the MBean server.
*
* @param name name of this interceptor
*
* @throws IllegalArgumentException if name contains <tt>null</tt> reference
*/
public AbstractSharedInterceptor(String name)
{
super(name);
}
// SharedInterceptor implementation ------------------------------
public ObjectName getObjectName()
{
return objectName;
}
public MBeanServer getMBeanServer()
{
return server;
}
/**
* Registers the interceptor to the MBean server. <p>
*
* The interceptor is registered under the
* {@link org.jboss.mx.service.ServiceConstants#JBOSSMX_DOMAIN JBOSSMX_DOMAIN}
* name. An interceptor's object name contains a <tt>type</tt> property and
* a <tt>name</tt> property. Property <tt>type</tt> always contains string
* <tt>'Interceptor'</tt> as its value. Interceptor's name is used as a value
* for the <tt>name</tt> property. Therefore, an interceptor created with
* name <tt>'Bart'</tt> can be found from the MBean server under object name: <br><pre>
*
* {@link org.jboss.mx.service.ServiceConstants#JBOSSMX_DOMAIN JBOSSMX_DOMAIN}:type=Interceptor,name=Bart,*
*
* </pre>
*
* If the log reference has not been set for this interceptor when it is
* registered, this implementation will register a log MBean via the system
* log manager under {@link org.jboss.mx.service.ServiceConstants#JBOSSMX_DOMAIN JBOSSMX}
* domain (see {@link org.jboss.mx.logging.SystemLogManager SystemLogManager}
* for details). The log instance's name will match the pattern: <br><pre>
*
* "JBossMX.Interceptor.<interceptor name>"
*
* </pre>
*
* @param server MBean server where this shared interceptor is registered
*/
public synchronized ObjectName register(MBeanServer server)
throws InterceptorNameConflictException
{
// store MBean server reference
this.server = server;
// check if log instance has been set
if (log == null)
log = Logger.getLogger("JBossMX.Interceptor." + name);
try
{
// store the object name for later use
objectName = createObjectName();
// query the server for this name
Set names = server.queryNames(objectName, null /* NO QUERY EXPR. */);
// if the query returns a non empty set, throw an exception
if (names.size() > 0)
throw new InterceptorNameConflictException(
"A shared interceptor named '" + name + "' already registered " +
"to this MBean server (" + AgentID.get(server) + ")"
);
// register the interceptor to server
ModelMBean rmm = RequiredModelMBeanInstantiator.instantiate();
rmm.setManagedResource(this, ModelMBeanConstants.OBJECT_REF);
rmm.setModelMBeanInfo(getManagementInterface());
server.registerMBean(rmm, objectName);
// mark the interceptor as shared
isShared = true;
}
catch (InstanceAlreadyExistsException e)
{
// we already checked that the instance doesn't exist with a query,
// however it is possible it was created by another thread before we
// actually had a chance to register
throw new InterceptorNameConflictException(
"A shared interceptor named '" + name + "' already registered " +
"to this MBean server (" + AgentID.get(server) + ")"
);
}
catch (Exception e)
{
// anything else indicates there's something much more wrong if
// we can't register a simple MBean, so just log an error
if (log != null)
log.error(e.toString(), e);
}
return objectName;
}
/**
* This method is part of the interceptor MBean's registration lifecycle.
* It is called before the MBean is registered to the server. Concrete
* interceptor implementations can override this method to provide
* initialization code that should be executed before the interceptor
* is registered. <p>
*
* Any exception that is propagated from this method to its caller will
* cancel the interceptor registration.
*
* @throws Exception if you want to cancel the interceptor registration
*/
public void init() throws Exception {}
/**
* This method is part of the interceptor MBean's registration lifecycle.
* It is called after the MBean is registered to the server. Concrete
* interceptor implementations can override this method to provide
* initialization code that should be executed once the MBean server and
* object name references for this interceptor have been resolved.
*/
public void start() {}
/**
* This method is part of the interceptor MBean's registration lifecycle.
* It is called before the MBean is unregistered from the server. Concrete
* interceptor implementations can override this method to provide
* cleanup code that should be executed before the interceptor is
* unregistered. <p>
*
* Any exception that is propagated from this method to its caller will
* cancel the interceptor unregistration.
*
* @throws Exception if you want to cancel the interceptor unregistration
*/
public void stop() throws Exception {}
/**
* This method is part of the interceptor MBean's registration lifecycle.
* It is called after the MBean has been unregistered from the server. Concrete
* interceptor implementations can override this method to provide
* cleanup code that should be executed once the interceptor is no longer
* registered to the MBean server.
*/
public void destroy() {}
// MBeanRegistration implementation ------------------------------
public ObjectName preRegister(MBeanServer server, ObjectName oname) throws Exception
{
this.server = server;
if (oname == null)
this.objectName = createObjectName();
else
this.objectName = oname;
init();
return objectName;
}
public void postRegister(Boolean registrationSuccesful) {
isShared = true;
start();
}
public void preDeregister() throws Exception {
stop();
isShared = false;
objectName = null;
}
public void postDeregister() {
destroy();
}
// AbstractInterceptor overrides ---------------------------------
/**
* Shared interceptors allows their name to be set only before they have
* been registered to the MBean server. After that the name is fixed and
* any attempt to invoke this method to change the name will yield a
* IllegalArgumentException.
*
* @param name name of this shared interceptor
*
* @throws IllegalArgumentException if there was an attempt to change the
* name after the interceptor had been registered to the server
*/
public synchronized void setName(String name)
{
if (isShared())
throw new IllegalArgumentException("Cannot change the interceptor name. Already registered.");
this.name = name;
}
// Object overrides ----------------------------------------------
/**
* Returns a string representation of this interceptor instance.
*
* @return string representation
*/
public String toString()
{
String className = getClass().getName();
int index = className.lastIndexOf('.');
return className.substring((index < 0) ? 0 : index) + "[" +
"name=" + name + "SHARED " + objectName + "]";
}
// Protected -----------------------------------------------------
/**
* Creates an object name for this interceptor. The object name contains a
* <tt>type</tt> property and a <tt>name</tt> property. Property <tt>type</tt>
* always contains string <tt>'Interceptor'</tt> as its value. Interceptor's
* name is used as a value for the <tt>name</tt> property. Therefore, an
* interceptor created with name <tt>'Bart'</tt> will generate an object name
* matching to pattern: <br><pre>
*
* {@link org.jboss.mx.service.ServiceConstants#JBOSSMX_DOMAIN JBOSSMX_DOMAIN}:type=Interceptor,name=Bart,*
*
* </pre>
*
* @return generated object name for this interceptor
*
* @throws MalformedObjectNameException if the object name could not be
* created
*/
protected ObjectName createObjectName() throws MalformedObjectNameException
{
// create the object name for this shared interceptor
Hashtable props = new Hashtable(2);
props.put("type", "Interceptor");
props.put("name", name);
props.put("ID", "0");
return new ObjectName(ServiceConstants.JBOSSMX_DOMAIN, props);
}
// Private -------------------------------------------------------
private ModelMBeanInfo getManagementInterface()
{
return new ModelMBeanInfoSupport(
this.getClass().getName(), // resource object class name
"Interceptor invocation interface", // description of the MBean
null, // attributes
null, // constructors
new ModelMBeanOperationInfo[] // operations
{
new ModelMBeanOperationInfo(
"invoke", // name
"Shared interceptor invoke operation.", // description
new MBeanParameterInfo[] // arguments
{
new MBeanParameterInfo(
"invocation", // name
Invocation.class.getName(), // type
"The invocation object." // description
)
},
Object.class.getName(), // return type
MBeanOperationInfo.ACTION_INFO // impact
)
},
null // notifications
);
}
}