/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.googlecode.perftrace.log4j.jmx;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Vector;
import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.DynamicMBean;
import javax.management.InstanceAlreadyExistsException;
import javax.management.InstanceNotFoundException;
import javax.management.JMException;
import javax.management.MBeanRegistration;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.NotCompliantMBeanException;
import javax.management.ObjectName;
import javax.management.RuntimeOperationsException;
import org.googlecode.perftrace.log4j.Appender;
import org.googlecode.perftrace.log4j.Logger;
public abstract class AbstractDynamicMBean implements DynamicMBean,
MBeanRegistration {
String dClassName;
MBeanServer server;
private final Vector mbeanList = new Vector();
/**
* Get MBean name.
* @param appender appender, may not be null.
* @return name.
* @since 1.2.16
*/
static protected String getAppenderName(final Appender appender){
String name = appender.getName();
if (name == null || name.trim().length() == 0) {
// try to get some form of a name, because null is not allowed (exception), and empty string certainly isn't useful in JMX..
name = appender.toString();
}
return name;
}
/**
* Enables the to get the values of several attributes of the Dynamic MBean.
*/
public
AttributeList getAttributes(String[] attributeNames) {
// Check attributeNames is not null to avoid NullPointerException later on
if (attributeNames == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("attributeNames[] cannot be null"),
"Cannot invoke a getter of " + dClassName);
}
AttributeList resultList = new AttributeList();
// if attributeNames is empty, return an empty result list
if (attributeNames.length == 0)
return resultList;
// build the result attribute list
for (int i=0 ; i<attributeNames.length ; i++){
try {
Object value = getAttribute((String) attributeNames[i]);
resultList.add(new Attribute(attributeNames[i],value));
} catch (JMException e) {
e.printStackTrace();
} catch (RuntimeException e) {
e.printStackTrace();
}
}
return(resultList);
}
/**
* Sets the values of several attributes of the Dynamic MBean, and returns the
* list of attributes that have been set.
*/
public AttributeList setAttributes(AttributeList attributes) {
// Check attributes is not null to avoid NullPointerException later on
if (attributes == null) {
throw new RuntimeOperationsException(
new IllegalArgumentException("AttributeList attributes cannot be null"),
"Cannot invoke a setter of " + dClassName);
}
AttributeList resultList = new AttributeList();
// if attributeNames is empty, nothing more to do
if (attributes.isEmpty())
return resultList;
// for each attribute, try to set it and add to the result list if successfull
for (Iterator i = attributes.iterator(); i.hasNext();) {
Attribute attr = (Attribute) i.next();
try {
setAttribute(attr);
String name = attr.getName();
Object value = getAttribute(name);
resultList.add(new Attribute(name,value));
} catch(JMException e) {
e.printStackTrace();
} catch(RuntimeException e) {
e.printStackTrace();
}
}
return(resultList);
}
protected
abstract
Logger getLogger();
public
void postDeregister() {
getLogger().debug("postDeregister is called.");
}
public
void postRegister(java.lang.Boolean registrationDone) {
}
public
ObjectName preRegister(MBeanServer server, ObjectName name) {
getLogger().debug("preRegister called. Server="+server+ ", name="+name);
this.server = server;
return name;
}
/**
* Registers MBean instance in the attached server. Must <em>NOT</em>
* be called before registration of this instance.
*/
protected
void registerMBean(Object mbean, ObjectName objectName)
throws InstanceAlreadyExistsException, MBeanRegistrationException,
NotCompliantMBeanException {
server.registerMBean(mbean, objectName);
mbeanList.add(objectName);
}
/**
* Performs cleanup for deregistering this MBean. Default implementation
* unregisters MBean instances which are registered using
* {@link #registerMBean(Object mbean, ObjectName objectName)}.
*/
public
void preDeregister() {
getLogger().debug("preDeregister called.");
Enumeration iterator = mbeanList.elements();
while (iterator.hasMoreElements()) {
ObjectName name = (ObjectName) iterator.nextElement();
try {
server.unregisterMBean(name);
} catch (InstanceNotFoundException e) {
getLogger().warn("Missing MBean " + name.getCanonicalName());
} catch (MBeanRegistrationException e) {
getLogger().warn("Failed unregistering " + name.getCanonicalName());
}
}
}
}