/*
* 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.apache.tomcat.util.modeler;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.lang.management.ManagementFactory;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import javax.management.DynamicMBean;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.modeler.modules.ModelerSource;
/*
Issues:
- exceptions - too many "throws Exception"
- double check the interfaces
- start removing the use of the experimental methods in tomcat, then remove
the methods ( before 1.1 final )
- is the security enough to prevent Registry beeing used to avoid the permission
checks in the mbean server ?
*/
/**
* Registry for modeler MBeans.
*
* This is the main entry point into modeler. It provides methods to create
* and manipulate model mbeans and simplify their use.
*
* Starting with version 1.1, this is no longer a singleton and the static
* methods are strongly deprecated. In a container environment we can expect
* different applications to use different registries.
*
* This class is itself an mbean.
*
* IMPORTANT: public methods not marked with @since x.x are experimental or
* internal. Should not be used.
*
* @author Craig R. McClanahan
* @author Costin Manolache
*/
public class Registry implements RegistryMBean, MBeanRegistration {
/**
* The Log instance to which we will write our log messages.
*/
private static Log log = LogFactory.getLog(Registry.class);
// Support for the factory methods
/** Will be used to isolate different apps and enhance security.
*/
private static HashMap perLoaderRegistries=null;
/**
* The registry instance created by our factory method the first time
* it is called.
*/
private static Registry registry = null;
// Per registy fields
/**
* The <code>MBeanServer</code> instance that we will use to register
* management beans.
*/
private MBeanServer server = null;
/**
* The set of ManagedBean instances for the beans this registry
* knows about, keyed by name.
*/
private HashMap descriptors = new HashMap();
/** List of managed byeans, keyed by class name
*/
private HashMap descriptorsByClass = new HashMap();
// map to avoid duplicated searching or loading descriptors
private HashMap searchedPaths=new HashMap();
private Object guard;
// Id - small ints to use array access. No reset on stop()
// Used for notifications
private Hashtable idDomains=new Hashtable();
private Hashtable ids=new Hashtable();
// ----------------------------------------------------------- Constructors
/**
*/
public Registry() {
super();
}
// -------------------- Static methods --------------------
// Factories
/**
* Factory method to create (if necessary) and return our
* <code>Registry</code> instance.
*
* Use this method to obtain a Registry - all other static methods
* are deprecated and shouldn't be used.
*
* The current version uses a static - future versions could use
* the thread class loader.
*
* @param key Support for application isolation. If null, the context class
* loader will be used ( if setUseContextClassLoader is called ) or the
* default registry is returned.
* @param guard Prevent access to the registry by untrusted components
*
* @since 1.1
*/
public synchronized static Registry getRegistry(Object key, Object guard) {
Registry localRegistry;
if( perLoaderRegistries!=null ) {
if( key==null )
key=Thread.currentThread().getContextClassLoader();
if( key != null ) {
localRegistry=(Registry)perLoaderRegistries.get(key);
if( localRegistry == null ) {
localRegistry=new Registry();
// localRegistry.key=key;
localRegistry.guard=guard;
perLoaderRegistries.put( key, localRegistry );
return localRegistry;
}
if( localRegistry.guard != null &&
localRegistry.guard != guard ) {
return null; // XXX Should I throw a permission ex ?
}
return localRegistry;
}
}
// static
if (registry == null) {
registry = new Registry();
}
if( registry.guard != null &&
registry.guard != guard ) {
return null;
}
return (registry);
}
/**
* Allow containers to isolate apps. Can be called only once.
* It is highly recommended you call this method if using Registry in
* a container environment. The default is false for backward compatibility
*
* @param enable
* @since 1.1
*/
public static void setUseContextClassLoader( boolean enable ) {
if( enable ) {
perLoaderRegistries=new HashMap();
}
}
// -------------------- Generic methods --------------------
/** Lifecycle method - clean up the registry metadata.
* Called from resetMetadata().
*
* @since 1.1
*/
public void stop() {
descriptorsByClass = new HashMap();
descriptors = new HashMap();
searchedPaths=new HashMap();
}
/**
* Load an extended mlet file. The source can be an URL, File or
* InputStream.
*
* All mbeans will be instantiated, registered and the attributes will be
* set. The result is a list of ObjectNames.
*
* @param source InputStream or URL of the file
* @param cl ClassLoader to be used to load the mbeans, or null to use the
* default JMX mechanism ( i.e. all registered loaders )
* @return List of ObjectName for the loaded mbeans
* @throws Exception
*
* @since 1.1
*/
public List loadMBeans( Object source, ClassLoader cl )
throws Exception
{
return load("MbeansSource", source, null );
}
/** Load descriptors. The source can be a File or URL or InputStream for the
* descriptors file. In the case of File and URL, if the extension is ".ser"
* a serialized version will be loaded.
*
* This method should be used to explicitely load metadata - but this is not
* required in most cases. The registerComponent() method will find metadata
* in the same pacakge.
*
* @param source
*/
public void loadMetadata(Object source ) throws Exception {
loadDescriptors( null, source, null );
}
/** Register a bean by creating a modeler mbean and adding it to the
* MBeanServer.
*
* If metadata is not loaded, we'll look up and read a file named
* "mbeans-descriptors.ser" or "mbeans-descriptors.xml" in the same package
* or parent.
*
* If the bean is an instance of DynamicMBean. it's metadata will be converted
* to a model mbean and we'll wrap it - so modeler services will be supported
*
* If the metadata is still not found, introspection will be used to extract
* it automatically.
*
* If an mbean is already registered under this name, it'll be first
* unregistered.
*
* If the component implements MBeanRegistration, the methods will be called.
* If the method has a method "setRegistry" that takes a RegistryMBean as
* parameter, it'll be called with the current registry.
*
*
* @param bean Object to be registered
* @param oname Name used for registration
* @param type The type of the mbean, as declared in mbeans-descriptors. If
* null, the name of the class will be used. This can be used as a hint or
* by subclasses.
*
* @since 1.1
*/
public void registerComponent(Object bean, String oname, String type)
throws Exception
{
registerComponent(bean, new ObjectName(oname), type);
}
/** Unregister a component. We'll first check if it is registered,
* and mask all errors. This is mostly a helper.
*
* @param oname
*
* @since 1.1
*/
public void unregisterComponent( String oname ) {
try {
unregisterComponent(new ObjectName(oname));
} catch (MalformedObjectNameException e) {
log.info("Error creating object name " + e );
}
}
/** Invoke a operation on a list of mbeans. Can be used to implement
* lifecycle operations.
*
* @param mbeans list of ObjectName on which we'll invoke the operations
* @param operation Name of the operation ( init, start, stop, etc)
* @param failFirst If false, exceptions will be ignored
* @throws Exception
* @since 1.1
*/
public void invoke( List mbeans, String operation, boolean failFirst )
throws Exception
{
if( mbeans==null ) {
return;
}
Iterator itr=mbeans.iterator();
while(itr.hasNext()) {
Object current=itr.next();
ObjectName oN=null;
try {
if( current instanceof ObjectName) {
oN=(ObjectName)current;
}
if( current instanceof String ) {
oN=new ObjectName( (String)current );
}
if( oN==null ) {
continue;
}
if( getMethodInfo(oN, operation) == null) {
continue;
}
getMBeanServer().invoke(oN, operation,
new Object[] {}, new String[] {});
} catch( Exception t ) {
if( failFirst ) throw t;
log.info("Error initializing " + current + " " + t.toString());
}
}
}
// -------------------- ID registry --------------------
/** Return an int ID for faster access. Will be used for notifications
* and for other operations we want to optimize.
*
* @param domain Namespace
* @param name Type of the notification
* @return An unique id for the domain:name combination
* @since 1.1
*/
public synchronized int getId( String domain, String name) {
if( domain==null) {
domain="";
}
Hashtable domainTable=(Hashtable)idDomains.get( domain );
if( domainTable == null ) {
domainTable=new Hashtable();
idDomains.put( domain, domainTable);
}
if( name==null ) {
name="";
}
Integer i=(Integer)domainTable.get(name);
if( i!= null ) {
return i.intValue();
}
int id[]=(int [])ids.get( domain );
if( id == null ) {
id=new int[1];
ids.put( domain, id);
}
int code=id[0]++;
domainTable.put( name, new Integer( code ));
return code;
}
// -------------------- Metadata --------------------
// methods from 1.0
/**
* Add a new bean metadata to the set of beans known to this registry.
* This is used by internal components.
*
* @param bean The managed bean to be added
* @since 1.0
*/
public void addManagedBean(ManagedBean bean) {
// XXX Use group + name
descriptors.put(bean.getName(), bean);
if( bean.getType() != null ) {
descriptorsByClass.put( bean.getType(), bean );
}
}
/**
* Find and return the managed bean definition for the specified
* bean name, if any; otherwise return <code>null</code>.
*
* @param name Name of the managed bean to be returned. Since 1.1, both
* short names or the full name of the class can be used.
* @since 1.0
*/
public ManagedBean findManagedBean(String name) {
// XXX Group ?? Use Group + Type
ManagedBean mb=((ManagedBean) descriptors.get(name));
if( mb==null )
mb=(ManagedBean)descriptorsByClass.get(name);
return mb;
}
/**
* Return the set of bean names for all managed beans known to
* this registry.
*
* @since 1.0
*/
public String[] findManagedBeans() {
return ((String[]) descriptors.keySet().toArray(new String[0]));
}
/**
* Return the set of bean names for all managed beans known to
* this registry that belong to the specified group.
*
* @param group Name of the group of interest, or <code>null</code>
* to select beans that do <em>not</em> belong to a group
* @since 1.0
*/
public String[] findManagedBeans(String group) {
ArrayList results = new ArrayList();
Iterator items = descriptors.values().iterator();
while (items.hasNext()) {
ManagedBean item = (ManagedBean) items.next();
if ((group == null) && (item.getGroup() == null)) {
results.add(item.getName());
} else if (group.equals(item.getGroup())) {
results.add(item.getName());
}
}
String values[] = new String[results.size()];
return ((String[]) results.toArray(values));
}
/**
* Remove an existing bean from the set of beans known to this registry.
*
* @param bean The managed bean to be removed
* @since 1.0
*/
public void removeManagedBean(ManagedBean bean) {
// TODO: change this to use group/name
descriptors.remove(bean.getName());
descriptorsByClass.remove( bean.getType());
}
// -------------------- Deprecated 1.0 methods --------------------
/**
* Factory method to create (if necessary) and return our
* <code>MBeanServer</code> instance.
*
* @since 1.0
* @deprecated Use the instance method
*/
public static MBeanServer getServer() {
return Registry.getRegistry().getMBeanServer();
}
/**
* Set the <code>MBeanServer</code> to be utilized for our
* registered management beans.
*
* @param mbeanServer The new <code>MBeanServer</code> instance
* @since 1.0
* @deprecated Use the instance method
*/
public static void setServer(MBeanServer mbeanServer) {
Registry.getRegistry().setMBeanServer(mbeanServer);
}
/**
* Load the registry from the XML input found in the specified input
* stream.
*
* @param stream InputStream containing the registry configuration
* information
*
* @exception Exception if any parsing or processing error occurs
* @deprecated use normal class method instead
* @since 1.0
*/
public static void loadRegistry(InputStream stream) throws Exception {
Registry registry = getRegistry();
registry.loadMetadata(stream);
}
/** Get a "singelton" registry, or one per thread if setUseContextLoader
* was called
*
* @deprecated Not enough info - use the method that takes CL and domain
* @since 1.0
*/
public synchronized static Registry getRegistry() {
return getRegistry(null, null);
}
// -------------------- Helpers --------------------
/** Get the type of an attribute of the object, from the metadata.
*
* @param oname
* @param attName
* @return null if metadata about the attribute is not found
* @since 1.1
*/
public String getType( ObjectName oname, String attName )
{
String type=null;
MBeanInfo info=null;
try {
info=server.getMBeanInfo(oname);
} catch (Exception e) {
log.info( "Can't find metadata for object" + oname );
return null;
}
MBeanAttributeInfo attInfo[]=info.getAttributes();
for( int i=0; i<attInfo.length; i++ ) {
if( attName.equals(attInfo[i].getName())) {
type=attInfo[i].getType();
return type;
}
}
return null;
}
/** Find the operation info for a method
*
* @param oname
* @param opName
* @return the operation info for the specified operation
*/
public MBeanOperationInfo getMethodInfo( ObjectName oname, String opName )
{
String type=null;
MBeanInfo info=null;
try {
info=server.getMBeanInfo(oname);
} catch (Exception e) {
log.info( "Can't find metadata " + oname );
return null;
}
MBeanOperationInfo attInfo[]=info.getOperations();
for( int i=0; i<attInfo.length; i++ ) {
if( opName.equals(attInfo[i].getName())) {
return attInfo[i];
}
}
return null;
}
/** Unregister a component. This is just a helper that
* avoids exceptions by checking if the mbean is already registered
*
* @param oname
*/
public void unregisterComponent( ObjectName oname ) {
try {
if( getMBeanServer().isRegistered(oname)) {
getMBeanServer().unregisterMBean(oname);
}
} catch( Throwable t ) {
log.error( "Error unregistering mbean ", t);
}
}
/**
* Factory method to create (if necessary) and return our
* <code>MBeanServer</code> instance.
*
*/
public synchronized MBeanServer getMBeanServer() {
long t1=System.currentTimeMillis();
if (server == null) {
if( MBeanServerFactory.findMBeanServer(null).size() > 0 ) {
server=(MBeanServer)MBeanServerFactory.findMBeanServer(null).get(0);
if( log.isDebugEnabled() ) {
log.debug("Using existing MBeanServer " + (System.currentTimeMillis() - t1 ));
}
} else {
server = ManagementFactory.getPlatformMBeanServer();
if( log.isDebugEnabled() ) {
log.debug("Creating MBeanServer"+ (System.currentTimeMillis() - t1 ));
}
}
}
return (server);
}
/** Find or load metadata.
*/
public ManagedBean findManagedBean(Object bean, Class beanClass, String type)
throws Exception
{
if( bean!=null && beanClass==null ) {
beanClass=bean.getClass();
}
if( type==null ) {
type=beanClass.getName();
}
// first look for existing descriptor
ManagedBean managed = findManagedBean(type);
// Search for a descriptor in the same package
if( managed==null ) {
// check package and parent packages
if( log.isDebugEnabled() ) {
log.debug( "Looking for descriptor ");
}
findDescriptor( beanClass, type );
managed=findManagedBean(type);
}
if( bean instanceof DynamicMBean ) {
if( log.isDebugEnabled() ) {
log.debug( "Dynamic mbean support ");
}
// Dynamic mbean
loadDescriptors("MbeansDescriptorsDynamicMBeanSource",
bean, type);
managed=findManagedBean(type);
}
// Still not found - use introspection
if( managed==null ) {
if( log.isDebugEnabled() ) {
log.debug( "Introspecting ");
}
// introspection
loadDescriptors("MbeansDescriptorsIntrospectionSource",
beanClass, type);
managed=findManagedBean(type);
if( managed==null ) {
log.warn( "No metadata found for " + type );
return null;
}
managed.setName( type );
addManagedBean(managed);
}
return managed;
}
/** EXPERIMENTAL Convert a string to object, based on type. Used by several
* components. We could provide some pluggability. It is here to keep
* things consistent and avoid duplication in other tasks
*
* @param type Fully qualified class name of the resulting value
* @param value String value to be converted
* @return Converted value
*/
public Object convertValue(String type, String value)
{
Object objValue=value;
if( type==null || "java.lang.String".equals( type )) {
// string is default
objValue=value;
} else if( "javax.management.ObjectName".equals( type ) ||
"ObjectName".equals( type )) {
try {
objValue=new ObjectName( value );
} catch (MalformedObjectNameException e) {
return null;
}
} else if( "java.lang.Integer".equals( type ) ||
"int".equals( type )) {
objValue=new Integer( value );
} else if( "java.lang.Long".equals( type ) ||
"long".equals( type )) {
objValue=new Long( value );
} else if( "java.lang.Boolean".equals( type ) ||
"boolean".equals( type )) {
objValue=new Boolean( value );
}
return objValue;
}
/** Experimental.
*
* @param sourceType
* @param source
* @param param
* @return List of descriptors
* @throws Exception
* @deprecated bad interface, mixing of metadata and mbeans
*/
public List load( String sourceType, Object source, String param)
throws Exception
{
if( log.isTraceEnabled()) {
log.trace("load " + source );
}
String location=null;
String type=null;
Object inputsource=null;
if( source instanceof DynamicMBean ) {
sourceType="MbeansDescriptorsDynamicMBeanSource";
inputsource=source;
} else if( source instanceof URL ) {
URL url=(URL)source;
location=url.toString();
type=param;
inputsource=url.openStream();
if( sourceType == null ) {
sourceType = sourceTypeFromExt(location);
}
} else if( source instanceof File ) {
location=((File)source).getAbsolutePath();
inputsource=new FileInputStream((File)source);
type=param;
if( sourceType == null ) {
sourceType = sourceTypeFromExt(location);
}
} else if( source instanceof InputStream ) {
type=param;
inputsource=source;
} else if( source instanceof Class ) {
location=((Class)source).getName();
type=param;
inputsource=source;
if( sourceType== null ) {
sourceType="MbeansDescriptorsIntrospectionSource";
}
}
if( sourceType==null ) {
sourceType="MbeansDescriptorsDigesterSource";
}
ModelerSource ds=getModelerSource(sourceType);
List mbeans=ds.loadDescriptors(this, location, type, inputsource);
return mbeans;
}
private String sourceTypeFromExt( String s ) {
if( s.endsWith( ".ser")) {
return "MbeansDescriptorsSerSource";
}
else if( s.endsWith(".xml")) {
return "MbeansDescriptorsDigesterSource";
}
return null;
}
/** Register a component
* XXX make it private
*
* @param bean
* @param oname
* @param type
* @throws Exception
*/
public void registerComponent(Object bean, ObjectName oname, String type)
throws Exception
{
if( log.isDebugEnabled() ) {
log.debug( "Managed= "+ oname);
}
if( bean ==null ) {
log.error("Null component " + oname );
return;
}
try {
if( type==null ) {
type=bean.getClass().getName();
}
ManagedBean managed = findManagedBean(bean.getClass(), type);
// The real mbean is created and registered
DynamicMBean mbean = managed.createMBean(bean);
if( getMBeanServer().isRegistered( oname )) {
if( log.isDebugEnabled()) {
log.debug("Unregistering existing component " + oname );
}
getMBeanServer().unregisterMBean( oname );
}
getMBeanServer().registerMBean( mbean, oname);
} catch( Exception ex) {
log.error("Error registering " + oname, ex );
throw ex;
}
}
/** Lookup the component descriptor in the package and
* in the parent packages.
*
* @param packageName
*/
public void loadDescriptors( String packageName, ClassLoader classLoader ) {
String res=packageName.replace( '.', '/');
if( log.isTraceEnabled() ) {
log.trace("Finding descriptor " + res );
}
if( searchedPaths.get( packageName ) != null ) {
return;
}
String descriptors=res + "/mbeans-descriptors.ser";
URL dURL=classLoader.getResource( descriptors );
if( dURL == null ) {
descriptors=res + "/mbeans-descriptors.xml";
dURL=classLoader.getResource( descriptors );
}
if( dURL == null ) {
return;
}
log.debug( "Found " + dURL);
searchedPaths.put( packageName, dURL );
try {
if( descriptors.endsWith(".xml" ))
loadDescriptors("MbeansDescriptorsDigesterSource", dURL, null);
else
loadDescriptors("MbeansDescriptorsSerSource", dURL, null);
return;
} catch(Exception ex ) {
log.error("Error loading " + dURL);
}
return;
}
/** Experimental. Will become private, some code may still use it
*
* @param sourceType
* @param source
* @param param
* @throws Exception
* @deprecated
*/
public void loadDescriptors( String sourceType, Object source, String param)
throws Exception
{
List mbeans=load( sourceType, source, param );
if( mbeans == null) return;
Iterator itr=mbeans.iterator();
while( itr.hasNext() ) {
Object mb=itr.next();
if( mb instanceof ManagedBean) {
addManagedBean((ManagedBean)mb);
}
}
}
/** Lookup the component descriptor in the package and
* in the parent packages.
*
* @param beanClass
* @param type
*/
private void findDescriptor( Class beanClass, String type ) {
if( type==null ) {
type=beanClass.getName();
}
ClassLoader classLoader=null;
if( beanClass!=null ) {
classLoader=beanClass.getClassLoader();
}
if( classLoader==null ) {
classLoader=Thread.currentThread().getContextClassLoader();
}
if( classLoader==null ) {
classLoader=this.getClass().getClassLoader();
}
String className=type;
String pkg=className;
while( pkg.indexOf( ".") > 0 ) {
int lastComp=pkg.lastIndexOf( ".");
if( lastComp <= 0 ) return;
pkg=pkg.substring(0, lastComp);
if( searchedPaths.get( pkg ) != null ) {
return;
}
loadDescriptors(pkg, classLoader);
}
return;
}
private ModelerSource getModelerSource( String type )
throws Exception
{
if( type==null ) type="MbeansDescriptorsDigesterSource";
if( type.indexOf( ".") < 0 ) {
type="org.apache.tomcat.util.modeler.modules." + type;
}
Class c=Class.forName( type );
ModelerSource ds=(ModelerSource)c.newInstance();
return ds;
}
// -------------------- Registration --------------------
public ObjectName preRegister(MBeanServer server,
ObjectName name) throws Exception
{
this.server=server;
return name;
}
public void postRegister(Boolean registrationDone) {
}
public void preDeregister() throws Exception {
}
public void postDeregister() {
}
// -------------------- DEPRECATED METHODS --------------------
// May still be used in tomcat
// Never part of an official release
/** Called by a registry or by the container to unload a loader
* @param loader
*/
public void unregisterRegistry(ClassLoader loader ) {
// XXX Cleanup ?
perLoaderRegistries.remove(loader);
}
public ManagedBean findManagedBean(Class beanClass, String type)
throws Exception
{
return findManagedBean(null, beanClass, type);
}
/**
* Set the <code>MBeanServer</code> to be utilized for our
* registered management beans.
*
* @param server The new <code>MBeanServer</code> instance
*/
public void setMBeanServer( MBeanServer server ) {
this.server=server;
}
public void resetMetadata() {
stop();
}
/**
* Load the registry from the XML input found in the specified input
* stream.
*
* @param source Source to be used to load. Can be an InputStream or URL.
*
* @exception Exception if any parsing or processing error occurs
*/
public void loadDescriptors( Object source )
throws Exception
{
loadDescriptors("MbeansDescriptorsDigesterSource", source, null );
}
/** @deprecated - may still be used in code using pre-1.1 builds
*/
public void registerComponent(Object bean, String domain, String type,
String name)
throws Exception
{
StringBuffer sb=new StringBuffer();
sb.append( domain ).append(":");
sb.append( name );
String nameStr=sb.toString();
ObjectName oname=new ObjectName( nameStr );
registerComponent(bean, oname, type );
}
// should be removed
public void unregisterComponent( String domain, String name ) {
try {
ObjectName oname=new ObjectName( domain + ":" + name );
// XXX remove from our tables.
getMBeanServer().unregisterMBean( oname );
} catch( Throwable t ) {
log.error( "Error unregistering mbean ", t );
}
}
/**
* Load the registry from a cached .ser file. This is typically 2-3 times
* faster than parsing the XML.
*
* @param source Source to be used to load. Can be an InputStream or URL.
*
* @exception Exception if any parsing or processing error occurs
* @deprecated Loaded automatically or using a File or Url ending in .ser
*/
public void loadCachedDescriptors( Object source )
throws Exception
{
loadDescriptors("MbeansDescriptorsSerSource", source, null );
}
}