Jetty example source code file (ObjectMBean.java)
The Jetty ObjectMBean.java source code//========================================================================
//Copyright 2004 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//Licensed 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.mortbay.management;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.Set;
import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanConstructorInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.modelmbean.ModelMBean;
import org.mortbay.log.Log;
import org.mortbay.util.LazyList;
import org.mortbay.util.Loader;
import org.mortbay.util.TypeUtil;
/* ------------------------------------------------------------ */
/** ObjectMBean.
* A dynamic MBean that can wrap an arbitary Object instance.
* the attributes and methods exposed by this bean are controlled by
* the merge of property bundles discovered by names related to all
* superclasses and all superinterfaces.
*
* Attributes and methods exported may be "Object" and must exist on the
* wrapped object, or "MBean" and must exist on a subclass of OBjectMBean
* or "MObject" which exists on the wrapped object, but whose values are
* converted to MBean object names.
*
*/
public class ObjectMBean implements DynamicMBean
{
private static Class[] OBJ_ARG = new Class[]{Object.class};
protected Object _managed;
private MBeanInfo _info;
private Map _getters=new HashMap();
private Map _setters=new HashMap();
private Map _methods=new HashMap();
private Set _convert=new HashSet();
private ClassLoader _loader;
private MBeanContainer _mbeanContainer;
private static String OBJECT_NAME_CLASS = ObjectName.class.getName();
private static String OBJECT_NAME_ARRAY_CLASS = ObjectName[].class.getName();
/* ------------------------------------------------------------ */
/**
* Create MBean for Object. Attempts to create an MBean for the object by searching the package
* and class name space. For example an object of the type
*
* <PRE>
* class com.acme.MyClass extends com.acme.util.BaseClass implements com.acme.Iface
* </PRE>
*
* Then this method would look for the following classes:
* <UL>
* <LI>com.acme.management.MyClassMBean
* <LI>com.acme.util.management.BaseClassMBean
* <LI>org.mortbay.management.ObjectMBean
* </UL>
*
* @param o The object
* @return A new instance of an MBean for the object or null.
*/
public static Object mbeanFor(Object o)
{
try
{
Class oClass = o.getClass();
Object mbean = null;
while (mbean == null && oClass != null)
{
String pName = oClass.getPackage().getName();
String cName = oClass.getName().substring(pName.length() + 1);
String mName = pName + ".management." + cName + "MBean";
try
{
Class mClass = (Object.class.equals(oClass))?oClass=ObjectMBean.class:Loader.loadClass(oClass,mName,true);
if (Log.isDebugEnabled())
Log.debug("mbeanFor " + o + " mClass=" + mClass);
try
{
Constructor constructor = mClass.getConstructor(OBJ_ARG);
mbean=constructor.newInstance(new Object[]{o});
}
catch(Exception e)
{
Log.ignore(e);
if (ModelMBean.class.isAssignableFrom(mClass))
{
mbean=mClass.newInstance();
((ModelMBean)mbean).setManagedResource(o, "objectReference");
}
}
if (Log.isDebugEnabled())
Log.debug("mbeanFor " + o + " is " + mbean);
return mbean;
}
catch (ClassNotFoundException e)
{
if (e.toString().endsWith("MBean"))
Log.ignore(e);
else
Log.warn(e);
}
catch (Error e)
{
Log.warn(e);
mbean = null;
}
catch (Exception e)
{
Log.warn(e);
mbean = null;
}
oClass = oClass.getSuperclass();
}
}
catch (Exception e)
{
Log.ignore(e);
}
return null;
}
public ObjectMBean(Object managedObject)
{
_managed = managedObject;
_loader = Thread.currentThread().getContextClassLoader();
}
public Object getManagedObject()
{
return _managed;
}
public ObjectName getObjectName()
{
return null;
}
public String getObjectNameBasis()
{
return null;
}
protected void setMBeanContainer(MBeanContainer container)
{
this._mbeanContainer = container;
}
public MBeanContainer getMBeanContainer ()
{
return this._mbeanContainer;
}
public MBeanInfo getMBeanInfo()
{
try
{
if (_info==null)
{
// Start with blank lazy lists attributes etc.
String desc=null;
Object attributes=null;
Object constructors=null;
Object operations=null;
Object notifications=null;
// Find list of classes that can influence the mbean
Class o_class=_managed.getClass();
Object influences = findInfluences(null, _managed.getClass());
// Set to record defined items
Set defined=new HashSet();
// For each influence
for (int i=0;i<LazyList.size(influences);i++)
{
Class oClass = (Class)LazyList.get(influences, i);
// look for a bundle defining methods
if (Object.class.equals(oClass))
oClass=ObjectMBean.class;
String pName = oClass.getPackage().getName();
String cName = oClass.getName().substring(pName.length() + 1);
String rName = pName.replace('.', '/') + "/management/" + cName+"-mbean";
try
{
Log.debug(rName);
ResourceBundle bundle = Loader.getResourceBundle(o_class, rName,true,Locale.getDefault());
// Extract meta data from bundle
Enumeration e = bundle.getKeys();
while (e.hasMoreElements())
{
String key = (String)e.nextElement();
String value = bundle.getString(key);
// Determin if key is for mbean , attribute or for operation
if (key.equals(cName))
{
// set the mbean description
if (desc==null)
desc=value;
}
else if (key.indexOf('(')>0)
{
// define an operation
if (!defined.contains(key) && key.indexOf('[')<0)
{
defined.add(key);
operations=LazyList.add(operations,defineOperation(key, value, bundle));
}
}
else
{
// define an attribute
if (!defined.contains(key))
{
defined.add(key);
attributes=LazyList.add(attributes,defineAttribute(key, value));
}
}
}
}
catch(MissingResourceException e)
{
Log.ignore(e);
}
}
_info = new MBeanInfo(o_class.getName(),
desc,
(MBeanAttributeInfo[])LazyList.toArray(attributes, MBeanAttributeInfo.class),
(MBeanConstructorInfo[])LazyList.toArray(constructors, MBeanConstructorInfo.class),
(MBeanOperationInfo[])LazyList.toArray(operations, MBeanOperationInfo.class),
(MBeanNotificationInfo[])LazyList.toArray(notifications, MBeanNotificationInfo.class));
}
}
catch(RuntimeException e)
{
Log.warn(e);
throw e;
}
return _info;
}
/* ------------------------------------------------------------ */
public Object getAttribute(String name) throws AttributeNotFoundException, MBeanException, ReflectionException
{
Method getter = (Method) _getters.get(name);
if (getter == null)
throw new AttributeNotFoundException(name);
try
{
Object o = _managed;
if (getter.getDeclaringClass().isInstance(this))
o = this; // mbean method
// get the attribute
Object r=getter.invoke(o, (java.lang.Object[]) null);
// convert to ObjectName if need be.
if (r!=null && _convert.contains(name))
{
if (r.getClass().isArray())
{
ObjectName[] on = new ObjectName[Array.getLength(r)];
for (int i=0;i<on.length;i++)
on[i]=_mbeanContainer.findMBean(Array.get(r, i));
r=on;
}
else
{
ObjectName mbean = _mbeanContainer.findMBean(r);
if (mbean==null)
return null;
r=mbean;
}
}
return r;
}
catch (IllegalAccessException e)
{
Log.warn(Log.EXCEPTION, e);
throw new AttributeNotFoundException(e.toString());
}
catch (InvocationTargetException e)
{
Log.warn(Log.EXCEPTION, e);
throw new ReflectionException((Exception) e.getTargetException());
}
}
/* ------------------------------------------------------------ */
public AttributeList getAttributes(String[] names)
{
AttributeList results = new AttributeList(names.length);
for (int i = 0; i < names.length; i++)
{
try
{
results.add(new Attribute(names[i], getAttribute(names[i])));
}
catch (Exception e)
{
Log.warn(Log.EXCEPTION, e);
}
}
return results;
}
/* ------------------------------------------------------------ */
public void setAttribute(Attribute attr) throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException, ReflectionException
{
if (attr == null)
return;
if (Log.isDebugEnabled())
Log.debug("setAttribute " + _managed + ":" +attr.getName() + "=" + attr.getValue());
Method setter = (Method) _setters.get(attr.getName());
if (setter == null)
throw new AttributeNotFoundException(attr.getName());
try
{
Object o = _managed;
if (setter.getDeclaringClass().isInstance(this))
o = this;
// get the value
Object value = attr.getValue();
// convert from ObjectName if need be
if (value!=null && _convert.contains(attr.getName()))
{
if (value.getClass().isArray())
{
Class t=setter.getParameterTypes()[0].getComponentType();
Object na = Array.newInstance(t,Array.getLength(value));
for (int i=Array.getLength(value);i-->0;)
Array.set(na, i, _mbeanContainer.findBean((ObjectName)Array.get(value, i)));
value=na;
}
else
value=_mbeanContainer.findBean((ObjectName)value);
}
// do the setting
setter.invoke(o, new Object[]{ value });
}
catch (IllegalAccessException e)
{
Log.warn(Log.EXCEPTION, e);
throw new AttributeNotFoundException(e.toString());
}
catch (InvocationTargetException e)
{
Log.warn(Log.EXCEPTION, e);
throw new ReflectionException((Exception) e.getTargetException());
}
}
/* ------------------------------------------------------------ */
public AttributeList setAttributes(AttributeList attrs)
{
Log.debug("setAttributes");
AttributeList results = new AttributeList(attrs.size());
Iterator iter = attrs.iterator();
while (iter.hasNext())
{
try
{
Attribute attr = (Attribute) iter.next();
setAttribute(attr);
results.add(new Attribute(attr.getName(), getAttribute(attr.getName())));
}
catch (Exception e)
{
Log.warn(Log.EXCEPTION, e);
}
}
return results;
}
/* ------------------------------------------------------------ */
public Object invoke(String name, Object[] params, String[] signature) throws MBeanException, ReflectionException
{
if (Log.isDebugEnabled())
Log.debug("invoke " + name);
String methodKey = name + "(";
if (signature != null)
for (int i = 0; i < signature.length; i++)
methodKey += (i > 0 ? "," : "") + signature[i];
methodKey += ")";
ClassLoader old_loader=Thread.currentThread().getContextClassLoader();
try
{
Thread.currentThread().setContextClassLoader(_loader);
Method method = (Method) _methods.get(methodKey);
if (method == null)
throw new NoSuchMethodException(methodKey);
Object o = _managed;
if (method.getDeclaringClass().isInstance(this))
o = this;
return method.invoke(o, params);
}
catch (NoSuchMethodException e)
{
Log.warn(Log.EXCEPTION, e);
throw new ReflectionException(e);
}
catch (IllegalAccessException e)
{
Log.warn(Log.EXCEPTION, e);
throw new MBeanException(e);
}
catch (InvocationTargetException e)
{
Log.warn(Log.EXCEPTION, e);
throw new ReflectionException((Exception) e.getTargetException());
}
finally
{
Thread.currentThread().setContextClassLoader(old_loader);
}
}
private static Object findInfluences(Object influences, Class aClass)
{
if (aClass!=null)
{
// This class is an influence
influences=LazyList.add(influences,aClass);
// So are the super classes
influences=findInfluences(influences,aClass.getSuperclass());
// So are the interfaces
Class[] ifs = aClass.getInterfaces();
for (int i=0;ifs!=null && i<ifs.length;i++)
influences=findInfluences(influences,ifs[i]);
}
return influences;
}
/* ------------------------------------------------------------ */
/**
* Define an attribute on the managed object. The meta data is defined by looking for standard
* getter and setter methods. Descriptions are obtained with a call to findDescription with the
* attribute name.
*
* @param name
* @param metaData "description" or "access:description" or "type:access:description" where type is
* one of: <ul>
* <li>"Object" The field/method is on the managed object.
* <li>"MBean" The field/method is on the mbean proxy object
* <li>"MObject" The field/method is on the managed object and value should be converted to MBean reference
* <li>"MMBean" The field/method is on the mbean proxy object and value should be converted to MBean reference
* </ul>
* the access is either "RW" or "RO".
*/
public MBeanAttributeInfo defineAttribute(String name, String metaData)
{
String description = "";
boolean writable = true;
boolean onMBean = false;
boolean convert = false;
if (metaData!= null)
{
String[] tokens = metaData.split(":", 3);
for (int t=0;t<tokens.length-1;t++)
{
tokens[t]=tokens[t].trim();
if ("RO".equals(tokens[t]))
writable=false;
else
{
onMBean=("MMBean".equalsIgnoreCase(tokens[t]) || "MBean".equalsIgnoreCase(tokens[t]));
convert=("MMBean".equalsIgnoreCase(tokens[t]) || "MObject".equalsIgnoreCase(tokens[t]));
}
}
description=tokens[tokens.length-1];
}
String uName = name.substring(0, 1).toUpperCase() + name.substring(1);
Class oClass = onMBean ? this.getClass() : _managed.getClass();
if (Log.isDebugEnabled())
Log.debug("defineAttribute "+name+" "+onMBean+":"+writable+":"+oClass+":"+description);
Class type = null;
Method getter = null;
Method setter = null;
Method[] methods = oClass.getMethods();
for (int m = 0; m < methods.length; m++)
{
if ((methods[m].getModifiers() & Modifier.PUBLIC) == 0)
continue;
// Look for a getter
if (methods[m].getName().equals("get" + uName) && methods[m].getParameterTypes().length == 0)
{
if (getter != null)
throw new IllegalArgumentException("Multiple getters for attr " + name+ " in "+oClass);
getter = methods[m];
if (type != null && !type.equals(methods[m].getReturnType()))
throw new IllegalArgumentException("Type conflict for attr " + name+ " in "+oClass);
type = methods[m].getReturnType();
}
// Look for an is getter
if (methods[m].getName().equals("is" + uName) && methods[m].getParameterTypes().length == 0)
{
if (getter != null)
throw new IllegalArgumentException("Multiple getters for attr " + name+ " in "+oClass);
getter = methods[m];
if (type != null && !type.equals(methods[m].getReturnType()))
throw new IllegalArgumentException("Type conflict for attr " + name+ " in "+oClass);
type = methods[m].getReturnType();
}
// look for a setter
if (writable && methods[m].getName().equals("set" + uName) && methods[m].getParameterTypes().length == 1)
{
if (setter != null)
throw new IllegalArgumentException("Multiple setters for attr " + name+ " in "+oClass);
setter = methods[m];
if (type != null && !type.equals(methods[m].getParameterTypes()[0]))
throw new IllegalArgumentException("Type conflict for attr " + name+ " in "+oClass);
type = methods[m].getParameterTypes()[0];
}
}
if (convert && type.isPrimitive() && !type.isArray())
throw new IllegalArgumentException("Cannot convert primative " + name);
if (getter == null && setter == null)
throw new IllegalArgumentException("No getter or setters found for " + name+ " in "+oClass);
try
{
// Remember the methods
_getters.put(name, getter);
_setters.put(name, setter);
MBeanAttributeInfo info=null;
if (convert)
{
_convert.add(name);
if (type.isArray())
info= new MBeanAttributeInfo(name,OBJECT_NAME_ARRAY_CLASS,description,getter!=null,setter!=null,getter!=null&&getter.getName().startsWith("is"));
else
info= new MBeanAttributeInfo(name,OBJECT_NAME_CLASS,description,getter!=null,setter!=null,getter!=null&&getter.getName().startsWith("is"));
}
else
info= new MBeanAttributeInfo(name,description,getter,setter);
return info;
}
catch (Exception e)
{
Log.warn(Log.EXCEPTION, e);
throw new IllegalArgumentException(e.toString());
}
}
/* ------------------------------------------------------------ */
/**
* Define an operation on the managed object. Defines an operation with parameters. Refection is
* used to determine find the method and it's return type. The description of the method is
* found with a call to findDescription on "name(signature)". The name and description of each
* parameter is found with a call to findDescription with "name(signature)[n]", the returned
* description is for the last parameter of the partial signature and is assumed to start with
* the parameter name, followed by a colon.
*
* @param metaData "description" or "impact:description" or "type:impact:description", type is
* the "Object","MBean", "MMBean" or "MObject" to indicate the method is on the object, the MBean or on the
* object but converted to an MBean reference, and impact is either "ACTION","INFO","ACTION_INFO" or "UNKNOWN".
*/
private MBeanOperationInfo defineOperation(String signature, String metaData, ResourceBundle bundle)
{
String[] tokens=metaData.split(":",3);
int i=tokens.length-1;
String description=tokens[i--];
String impact_name = i<0?"UNKNOWN":tokens[i--].trim();
if (i==0)
tokens[0]=tokens[0].trim();
boolean onMBean= i==0 && ("MBean".equalsIgnoreCase(tokens[0])||"MMBean".equalsIgnoreCase(tokens[0]));
boolean convert= i==0 && ("MObject".equalsIgnoreCase(tokens[0])||"MMBean".equalsIgnoreCase(tokens[0]));
if (Log.isDebugEnabled())
Log.debug("defineOperation "+signature+" "+onMBean+":"+impact_name+":"+description);
Class oClass = onMBean ? this.getClass() : _managed.getClass();
try
{
// Resolve the impact
int impact=MBeanOperationInfo.UNKNOWN;
if (impact_name==null || impact_name.equals("UNKNOWN"))
impact=MBeanOperationInfo.UNKNOWN;
else if (impact_name.equals("ACTION"))
impact=MBeanOperationInfo.ACTION;
else if (impact_name.equals("INFO"))
impact=MBeanOperationInfo.INFO;
else if (impact_name.equals("ACTION_INFO"))
impact=MBeanOperationInfo.ACTION_INFO;
else
Log.warn("Unknown impact '"+impact_name+"' for "+signature);
// split the signature
String[] parts=signature.split("[\\(\\)]");
String method_name=parts[0];
String arguments=parts.length==2?parts[1]:null;
String[] args=arguments==null?new String[0]:arguments.split(" *, *");
// Check types and normalize signature.
Class[] types = new Class[args.length];
MBeanParameterInfo[] pInfo = new MBeanParameterInfo[args.length];
signature=method_name;
for (i = 0; i < args.length; i++)
{
Class type = TypeUtil.fromName(args[i]);
if (type == null)
type = Thread.currentThread().getContextClassLoader().loadClass(args[i]);
types[i] = type;
args[i] = type.isPrimitive() ? TypeUtil.toName(type) : args[i];
signature+=(i>0?",":"(")+args[i];
}
signature+=(i>0?")":"()");
// Build param infos
for (i = 0; i < args.length; i++)
{
String param_desc = bundle.getString(signature + "[" + i + "]");
parts=param_desc.split(" *: *",2);
if (Log.isDebugEnabled())
Log.debug(parts[0]+": "+parts[1]);
pInfo[i] = new MBeanParameterInfo(parts[0].trim(), args[i], parts[1].trim());
}
// build the operation info
Method method = oClass.getMethod(method_name, types);
Class returnClass = method.getReturnType();
_methods.put(signature, method);
if (convert)
_convert.add(signature);
return new MBeanOperationInfo(method_name, description, pInfo, returnClass.isPrimitive() ? TypeUtil.toName(returnClass) : (returnClass.getName()), impact);
}
catch (Exception e)
{
Log.warn("Operation '"+signature+"'", e);
throw new IllegalArgumentException(e.toString());
}
}
}
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