org.apache.tomcat.util.modeler.BaseModelMBean Maven / Gradle / Ivy
/*
* 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.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Iterator;
import javax.management.Attribute;
import javax.management.AttributeChangeNotification;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InstanceNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.ListenerNotFoundException;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.Notification;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.RuntimeErrorException;
import javax.management.RuntimeOperationsException;
import javax.management.modelmbean.InvalidTargetObjectTypeException;
import javax.management.modelmbean.ModelMBeanNotificationBroadcaster;
import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
/*
* Changes from commons.modeler:
*
* - use DynamicMBean
* - remove methods not used in tomcat and redundant/not very generic
* - must be created from the ManagedBean - I don't think there were any direct
* uses, but now it is required.
* - some of the gratuitous flexibility removed - instead this is more predictive and
* strict with the use cases.
* - all Method and metadata is stored in ManagedBean. BaseModelBMean and ManagedBean act
* like Object and Class.
* - setModelMBean is no longer called on resources ( not used in tomcat )
* - no caching of Methods for now - operations and setters are not called repeatedly in most
* management use cases. Getters should't be called very frequently either - and even if they
* are, the overhead of getting the method should be small compared with other JMX costs ( RMI, etc ).
* We can add getter cache if needed.
* - removed unused constructor, fields
*
* TODO:
* - clean up catalina.mbeans, stop using weird inheritance
*/
/**
* Basic implementation of the DynamicMBean interface, which
* supports the minimal requirements of the interface contract.
*
* This can be used directly to wrap an existing java bean, or inside
* an mlet or anywhere an MBean would be used.
*
* Limitations:
*
* - Only managed resources of type
objectReference are
* supported.
* - Caching of attribute values and operation results is not supported.
* All calls to
invoke() are immediately executed.
* - Persistence of MBean attributes and operations is not supported.
* - All classes referenced as attribute types, operation parameters, or
* operation return values must be one of the following:
*
* - One of the Java primitive types (boolean, byte, char, double,
* float, integer, long, short). Corresponding value will be wrapped
* in the appropriate wrapper class automatically.
* - Operations that return no value should declare a return type of
*
void.
*
* - Attribute caching is not supported
*
*
* @author Craig R. McClanahan
* @author Costin Manolache
*/
public class BaseModelMBean implements DynamicMBean, MBeanRegistration, ModelMBeanNotificationBroadcaster {
private static final Log log = LogFactory.getLog(BaseModelMBean.class);
// ----------------------------------------------------------- Constructors
/**
* Construct a ModelMBean with default
* ModelMBeanInfo information.
*
* @exception MBeanException if the initializer of an object
* throws an exception
* @exception RuntimeOperationsException if an IllegalArgumentException
* occurs
*/
protected BaseModelMBean() throws MBeanException, RuntimeOperationsException {
super();
}
// ----------------------------------------------------- Instance Variables
protected ObjectName oname=null;
/**
* Notification broadcaster for attribute changes.
*/
protected BaseNotificationBroadcaster attributeBroadcaster = null;
/**
* Notification broadcaster for general notifications.
*/
protected BaseNotificationBroadcaster generalBroadcaster = null;
/** Metadata for the mbean instance.
*/
protected ManagedBean managedBean = null;
/**
* The managed resource this MBean is associated with (if any).
*/
protected Object resource = null;
// --------------------------------------------------- DynamicMBean Methods
// TODO: move to ManagedBean
static final Object[] NO_ARGS_PARAM = new Object[0];
protected String resourceType = null;
// key: operation val: invoke method
//private Hashtable invokeAttMap=new Hashtable();
/**
* Obtain and return the value of a specific attribute of this MBean.
*
* @param name Name of the requested attribute
*
* @exception AttributeNotFoundException if this attribute is not
* supported by this MBean
* @exception MBeanException if the initializer of an object
* throws an exception
* @exception ReflectionException if a Java reflection exception
* occurs when invoking the getter
*/
@Override
public Object getAttribute(String name)
throws AttributeNotFoundException, MBeanException,
ReflectionException {
// Validate the input parameters
if (name == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Attribute name is null"),
"Attribute name is null");
if( (resource instanceof DynamicMBean) &&
! ( resource instanceof BaseModelMBean )) {
return ((DynamicMBean)resource).getAttribute(name);
}
Method m=managedBean.getGetter(name, this, resource);
Object result = null;
try {
Class declaring = m.getDeclaringClass();
// workaround for catalina weird mbeans - the declaring class is BaseModelMBean.
// but this is the catalina class.
if( declaring.isAssignableFrom(this.getClass()) ) {
result = m.invoke(this, NO_ARGS_PARAM );
} else {
result = m.invoke(resource, NO_ARGS_PARAM );
}
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
if (t == null)
t = e;
if (t instanceof RuntimeException)
throw new RuntimeOperationsException
((RuntimeException) t, "Exception invoking method " + name);
else if (t instanceof Error)
throw new RuntimeErrorException
((Error) t, "Error invoking method " + name);
else
throw new MBeanException
(e, "Exception invoking method " + name);
} catch (Exception e) {
throw new MBeanException
(e, "Exception invoking method " + name);
}
// Return the results of this method invocation
// FIXME - should we validate the return type?
return (result);
}
/**
* Obtain and return the values of several attributes of this MBean.
*
* @param names Names of the requested attributes
*/
@Override
public AttributeList getAttributes(String names[]) {
// Validate the input parameters
if (names == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Attribute names list is null"),
"Attribute names list is null");
// Prepare our response, eating all exceptions
AttributeList response = new AttributeList();
for (int i = 0; i < names.length; i++) {
try {
response.add(new Attribute(names[i],getAttribute(names[i])));
} catch (Exception e) {
// Not having a particular attribute in the response
// is the indication of a getter problem
}
}
return (response);
}
public void setManagedBean(ManagedBean managedBean) {
this.managedBean = managedBean;
}
/**
* Return the MBeanInfo object for this MBean.
*/
@Override
public MBeanInfo getMBeanInfo() {
return managedBean.getMBeanInfo();
}
/**
* Invoke a particular method on this MBean, and return any returned
* value.
*
* IMPLEMENTATION NOTE - This implementation will
* attempt to invoke this method on the MBean itself, or (if not
* available) on the managed resource object associated with this
* MBean.
*
* @param name Name of the operation to be invoked
* @param params Array containing the method parameters of this operation
* @param signature Array containing the class names representing
* the signature of this operation
*
* @exception MBeanException if the initializer of an object
* throws an exception
* @exception ReflectionException if a Java reflection exception
* occurs when invoking a method
*/
@Override
public Object invoke(String name, Object params[], String signature[])
throws MBeanException, ReflectionException
{
if( (resource instanceof DynamicMBean) &&
! ( resource instanceof BaseModelMBean )) {
return ((DynamicMBean)resource).invoke(name, params, signature);
}
// Validate the input parameters
if (name == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Method name is null"),
"Method name is null");
if( log.isDebugEnabled()) log.debug("Invoke " + name);
Method method= managedBean.getInvoke(name, params, signature, this, resource);
// Invoke the selected method on the appropriate object
Object result = null;
try {
if( method.getDeclaringClass().isAssignableFrom( this.getClass()) ) {
result = method.invoke(this, params );
} else {
result = method.invoke(resource, params);
}
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
log.error("Exception invoking method " + name , t );
if (t == null)
t = e;
if (t instanceof RuntimeException)
throw new RuntimeOperationsException
((RuntimeException) t, "Exception invoking method " + name);
else if (t instanceof Error)
throw new RuntimeErrorException
((Error) t, "Error invoking method " + name);
else
throw new MBeanException
((Exception)t, "Exception invoking method " + name);
} catch (Exception e) {
log.error("Exception invoking method " + name , e );
throw new MBeanException
(e, "Exception invoking method " + name);
}
// Return the results of this method invocation
// FIXME - should we validate the return type?
return (result);
}
static Class getAttributeClass(String signature)
throws ReflectionException
{
if (signature.equals(Boolean.TYPE.getName()))
return Boolean.TYPE;
else if (signature.equals(Byte.TYPE.getName()))
return Byte.TYPE;
else if (signature.equals(Character.TYPE.getName()))
return Character.TYPE;
else if (signature.equals(Double.TYPE.getName()))
return Double.TYPE;
else if (signature.equals(Float.TYPE.getName()))
return Float.TYPE;
else if (signature.equals(Integer.TYPE.getName()))
return Integer.TYPE;
else if (signature.equals(Long.TYPE.getName()))
return Long.TYPE;
else if (signature.equals(Short.TYPE.getName()))
return Short.TYPE;
else {
try {
ClassLoader cl=Thread.currentThread().getContextClassLoader();
if( cl!=null )
return cl.loadClass(signature);
} catch( ClassNotFoundException e ) {
}
try {
return Class.forName(signature);
} catch (ClassNotFoundException e) {
throw new ReflectionException
(e, "Cannot find Class for " + signature);
}
}
}
/**
* Set the value of a specific attribute of this MBean.
*
* @param attribute The identification of the attribute to be set
* and the new value
*
* @exception AttributeNotFoundException if this attribute is not
* supported by this MBean
* @exception MBeanException if the initializer of an object
* throws an exception
* @exception ReflectionException if a Java reflection exception
* occurs when invoking the getter
*/
@Override
public void setAttribute(Attribute attribute)
throws AttributeNotFoundException, MBeanException,
ReflectionException
{
if( log.isDebugEnabled() )
log.debug("Setting attribute " + this + " " + attribute );
if( (resource instanceof DynamicMBean) &&
! ( resource instanceof BaseModelMBean )) {
try {
((DynamicMBean)resource).setAttribute(attribute);
} catch (InvalidAttributeValueException e) {
throw new MBeanException(e);
}
return;
}
// Validate the input parameters
if (attribute == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Attribute is null"),
"Attribute is null");
String name = attribute.getName();
Object value = attribute.getValue();
if (name == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Attribute name is null"),
"Attribute name is null");
Object oldValue=null;
//if( getAttMap.get(name) != null )
// oldValue=getAttribute( name );
Method m=managedBean.getSetter(name,this,resource);
try {
if( m.getDeclaringClass().isAssignableFrom( this.getClass()) ) {
m.invoke(this, new Object[] { value });
} else {
m.invoke(resource, new Object[] { value });
}
} catch (InvocationTargetException e) {
Throwable t = e.getTargetException();
if (t == null)
t = e;
if (t instanceof RuntimeException)
throw new RuntimeOperationsException
((RuntimeException) t, "Exception invoking method " + name);
else if (t instanceof Error)
throw new RuntimeErrorException
((Error) t, "Error invoking method " + name);
else
throw new MBeanException
(e, "Exception invoking method " + name);
} catch (Exception e) {
log.error("Exception invoking method " + name , e );
throw new MBeanException
(e, "Exception invoking method " + name);
}
try {
sendAttributeChangeNotification(new Attribute( name, oldValue),
attribute);
} catch(Exception ex) {
log.error("Error sending notification " + name, ex);
}
//attributes.put( name, value );
// if( source != null ) {
// // this mbean is associated with a source - maybe we want to persist
// source.updateField(oname, name, value);
// }
}
@Override
public String toString() {
if( resource==null )
return "BaseModelMbean[" + resourceType + "]";
return resource.toString();
}
/**
* Set the values of several attributes of this MBean.
*
* @param attributes THe names and values to be set
*
* @return The list of attributes that were set and their new values
*/
@Override
public AttributeList setAttributes(AttributeList attributes) {
AttributeList response = new AttributeList();
// Validate the input parameters
if (attributes == null)
return response;
// Prepare and return our response, eating all exceptions
String names[] = new String[attributes.size()];
int n = 0;
Iterator items = attributes.iterator();
while (items.hasNext()) {
Attribute item = (Attribute) items.next();
names[n++] = item.getName();
try {
setAttribute(item);
} catch (Exception e) {
// Ignore all exceptions
}
}
return (getAttributes(names));
}
// ----------------------------------------------------- ModelMBean Methods
/**
* Get the instance handle of the object against which we execute
* all methods in this ModelMBean management interface.
*
* @exception InstanceNotFoundException if the managed resource object
* cannot be found
* @exception InvalidTargetObjectTypeException if the managed resource
* object is of the wrong type
* @exception MBeanException if the initializer of the object throws
* an exception
* @exception RuntimeOperationsException if the managed resource or the
* resource type is null or invalid
*/
public Object getManagedResource()
throws InstanceNotFoundException, InvalidTargetObjectTypeException,
MBeanException, RuntimeOperationsException {
if (resource == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Managed resource is null"),
"Managed resource is null");
return resource;
}
/**
* Set the instance handle of the object against which we will execute
* all methods in this ModelMBean management interface.
*
* This method will detect and call "setModelMbean" method. A resource
* can implement this method to get a reference to the model mbean.
* The reference can be used to send notification and access the
* registry.
* The caller can provide the mbean instance or the object name to
* the resource, if needed.
*
* @param resource The resource object to be managed
* @param type The type of reference for the managed resource
* ("ObjectReference", "Handle", "IOR", "EJBHandle", or
* "RMIReference")
*
* @exception InstanceNotFoundException if the managed resource object
* cannot be found
* @exception MBeanException if the initializer of the object throws
* an exception
* @exception RuntimeOperationsException if the managed resource or the
* resource type is null or invalid
*/
public void setManagedResource(Object resource, String type)
throws InstanceNotFoundException,
MBeanException, RuntimeOperationsException
{
if (resource == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Managed resource is null"),
"Managed resource is null");
// if (!"objectreference".equalsIgnoreCase(type))
// throw new InvalidTargetObjectTypeException(type);
this.resource = resource;
this.resourceType = resource.getClass().getName();
// // Make the resource aware of the model mbean.
// try {
// Method m=resource.getClass().getMethod("setModelMBean",
// new Class[] {ModelMBean.class});
// if( m!= null ) {
// m.invoke(resource, new Object[] {this});
// }
// } catch( NoSuchMethodException t ) {
// // ignore
// } catch( Throwable t ) {
// log.error( "Can't set model mbean ", t );
// }
}
// ------------------------------ ModelMBeanNotificationBroadcaster Methods
/**
* Add an attribute change notification event listener to this MBean.
*
* @param listener Listener that will receive event notifications
* @param name Name of the attribute of interest, or null
* to indicate interest in all attributes
* @param handback Handback object to be sent along with event
* notifications
*
* @exception IllegalArgumentException if the listener parameter is null
*/
@Override
public void addAttributeChangeNotificationListener
(NotificationListener listener, String name, Object handback)
throws IllegalArgumentException {
if (listener == null)
throw new IllegalArgumentException("Listener is null");
if (attributeBroadcaster == null)
attributeBroadcaster = new BaseNotificationBroadcaster();
if( log.isDebugEnabled() )
log.debug("addAttributeNotificationListener " + listener);
BaseAttributeFilter filter = new BaseAttributeFilter(name);
attributeBroadcaster.addNotificationListener
(listener, filter, handback);
}
/**
* Remove an attribute change notification event listener from
* this MBean.
*
* @param listener The listener to be removed
* @param name The attribute name for which no more events are required
*
*
* @exception ListenerNotFoundException if this listener is not
* registered in the MBean
*/
@Override
public void removeAttributeChangeNotificationListener
(NotificationListener listener, String name)
throws ListenerNotFoundException {
if (listener == null)
throw new IllegalArgumentException("Listener is null");
if (attributeBroadcaster == null)
attributeBroadcaster = new BaseNotificationBroadcaster();
// FIXME - currently this removes *all* notifications for this listener
attributeBroadcaster.removeNotificationListener(listener);
}
/**
* Send an AttributeChangeNotification to all registered
* listeners.
*
* @param notification The AttributeChangeNotification
* that will be passed
*
* @exception MBeanException if an object initializer throws an
* exception
* @exception RuntimeOperationsException wraps IllegalArgumentException
* when the specified notification is null or invalid
*/
@Override
public void sendAttributeChangeNotification
(AttributeChangeNotification notification)
throws MBeanException, RuntimeOperationsException {
if (notification == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Notification is null"),
"Notification is null");
if (attributeBroadcaster == null)
return; // This means there are no registered listeners
if( log.isDebugEnabled() )
log.debug( "AttributeChangeNotification " + notification );
attributeBroadcaster.sendNotification(notification);
}
/**
* Send an AttributeChangeNotification to all registered
* listeners.
*
* @param oldValue The original value of the Attribute
* @param newValue The new value of the Attribute
*
* @exception MBeanException if an object initializer throws an
* exception
* @exception RuntimeOperationsException wraps IllegalArgumentException
* when the specified notification is null or invalid
*/
@Override
public void sendAttributeChangeNotification
(Attribute oldValue, Attribute newValue)
throws MBeanException, RuntimeOperationsException {
// Calculate the class name for the change notification
String type = null;
if (newValue.getValue() != null)
type = newValue.getValue().getClass().getName();
else if (oldValue.getValue() != null)
type = oldValue.getValue().getClass().getName();
else
return; // Old and new are both null == no change
AttributeChangeNotification notification =
new AttributeChangeNotification
(this, 1, System.currentTimeMillis(),
"Attribute value has changed",
oldValue.getName(), type,
oldValue.getValue(), newValue.getValue());
sendAttributeChangeNotification(notification);
}
/**
* Send a Notification to all registered listeners as a
* jmx.modelmbean.general notification.
*
* @param notification The Notification that will be passed
*
* @exception MBeanException if an object initializer throws an
* exception
* @exception RuntimeOperationsException wraps IllegalArgumentException
* when the specified notification is null or invalid
*/
@Override
public void sendNotification(Notification notification)
throws MBeanException, RuntimeOperationsException {
if (notification == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Notification is null"),
"Notification is null");
if (generalBroadcaster == null)
return; // This means there are no registered listeners
generalBroadcaster.sendNotification(notification);
}
/**
* Send a Notification which contains the specified string
* as a jmx.modelmbean.generic notification.
*
* @param message The message string to be passed
*
* @exception MBeanException if an object initializer throws an
* exception
* @exception RuntimeOperationsException wraps IllegalArgumentException
* when the specified notification is null or invalid
*/
@Override
public void sendNotification(String message)
throws MBeanException, RuntimeOperationsException {
if (message == null)
throw new RuntimeOperationsException
(new IllegalArgumentException("Message is null"),
"Message is null");
Notification notification = new Notification
("jmx.modelmbean.generic", this, 1, message);
sendNotification(notification);
}
// ---------------------------------------- NotificationBroadcaster Methods
/**
* Add a notification event listener to this MBean.
*
* @param listener Listener that will receive event notifications
* @param filter Filter object used to filter event notifications
* actually delivered, or null for no filtering
* @param handback Handback object to be sent along with event
* notifications
*
* @exception IllegalArgumentException if the listener parameter is null
*/
@Override
public void addNotificationListener(NotificationListener listener,
NotificationFilter filter,
Object handback)
throws IllegalArgumentException {
if (listener == null)
throw new IllegalArgumentException("Listener is null");
if( log.isDebugEnabled() ) log.debug("addNotificationListener " + listener);
if (generalBroadcaster == null)
generalBroadcaster = new BaseNotificationBroadcaster();
generalBroadcaster.addNotificationListener
(listener, filter, handback);
// We'll send the attribute change notifications to all listeners ( who care )
// The normal filtering can be used.
// The problem is that there is no other way to add attribute change listeners
// to a model mbean ( AFAIK ). I suppose the spec should be fixed.
if (attributeBroadcaster == null)
attributeBroadcaster = new BaseNotificationBroadcaster();
if( log.isDebugEnabled() )
log.debug("addAttributeNotificationListener " + listener);
attributeBroadcaster.addNotificationListener
(listener, filter, handback);
}
/**
* Return an MBeanNotificationInfo object describing the
* notifications sent by this MBean.
*/
@Override
public MBeanNotificationInfo[] getNotificationInfo() {
// Acquire the set of application notifications
MBeanNotificationInfo current[] = getMBeanInfo().getNotifications();
if (current == null)
current = new MBeanNotificationInfo[0];
MBeanNotificationInfo response[] =
new MBeanNotificationInfo[current.length + 2];
// Descriptor descriptor = null;
// Fill in entry for general notifications
// descriptor = new DescriptorSupport
// (new String[] { "name=GENERIC",
// "descriptorType=notification",
// "log=T",
// "severity=5",
// "displayName=jmx.modelmbean.generic" });
response[0] = new MBeanNotificationInfo
(new String[] { "jmx.modelmbean.generic" },
"GENERIC",
"Text message notification from the managed resource");
//descriptor);
// Fill in entry for attribute change notifications
// descriptor = new DescriptorSupport
// (new String[] { "name=ATTRIBUTE_CHANGE",
// "descriptorType=notification",
// "log=T",
// "severity=5",
// "displayName=jmx.attribute.change" });
response[1] = new MBeanNotificationInfo
(new String[] { "jmx.attribute.change" },
"ATTRIBUTE_CHANGE",
"Observed MBean attribute value has changed");
//descriptor);
// Copy remaining notifications as reported by the application
System.arraycopy(current, 0, response, 2, current.length);
return (response);
}
/**
* Remove a notification event listener from this MBean.
*
* @param listener The listener to be removed (any and all registrations
* for this listener will be eliminated)
*
* @exception ListenerNotFoundException if this listener is not
* registered in the MBean
*/
@Override
public void removeNotificationListener(NotificationListener listener)
throws ListenerNotFoundException {
if (listener == null)
throw new IllegalArgumentException("Listener is null");
if (generalBroadcaster == null)
generalBroadcaster = new BaseNotificationBroadcaster();
generalBroadcaster.removeNotificationListener(listener);
}
public String getModelerType() {
return resourceType;
}
public String getClassName() {
return getModelerType();
}
public ObjectName getJmxName() {
return oname;
}
public String getObjectName() {
if (oname != null) {
return oname.toString();
} else {
return null;
}
}
// -------------------- Registration --------------------
// XXX We can add some method patterns here- like setName() and
// setDomain() for code that doesn't implement the Registration
@Override
public ObjectName preRegister(MBeanServer server,
ObjectName name)
throws Exception
{
if( log.isDebugEnabled())
log.debug("preRegister " + resource + " " + name );
oname=name;
if( resource instanceof MBeanRegistration ) {
oname = ((MBeanRegistration)resource).preRegister(server, name );
}
return oname;
}
@Override
public void postRegister(Boolean registrationDone) {
if( resource instanceof MBeanRegistration ) {
((MBeanRegistration)resource).postRegister(registrationDone);
}
}
@Override
public void preDeregister() throws Exception {
if( resource instanceof MBeanRegistration ) {
((MBeanRegistration)resource).preDeregister();
}
}
@Override
public void postDeregister() {
if( resource instanceof MBeanRegistration ) {
((MBeanRegistration)resource).postDeregister();
}
}
}