org.jboss.mx.util.JMXInvocationHandler Maven / Gradle / Ivy
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* 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.util;
import java.io.Serializable;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.DynamicMBean;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.RuntimeErrorException;
import javax.management.RuntimeMBeanException;
import javax.management.RuntimeOperationsException;
/**
* Invocation handler for MBean proxies.
*
* @author Juha Lindfors.
* @version $Revision: 81019 $
*
*/
public class JMXInvocationHandler
implements ProxyContext, InvocationHandler, Serializable
{
private static final long serialVersionUID = 3714728148040623702L;
// Attributes -------------------------------------------------
/**
* Reference to the MBean server this proxy connects to.
*/
protected MBeanServer server = null;
/**
* The object name of the MBean this proxy represents.
*/
protected ObjectName objectName = null;
/**
* Default exception handler for the proxy.
*/
private ProxyExceptionHandler handler = new DefaultExceptionHandler();
/**
* MBean attribute meta data.
*/
private HashMap attributeMap = new HashMap();
/**
* Indicates whether Object.toString() should be delegated to the resource
* or handled by the proxy.
*/
private boolean delegateToStringToResource = false;
/**
* Indicates whether Object.equals() should be delegated to the resource
* or handled by the proxy.
*/
private boolean delegateEqualsToResource = false;
/**
* Indicates whether Object.hashCode() should be delegated to the resource
* or handled by the proxy.
*/
private boolean delegateHashCodeToResource = false;
// Constructors -----------------------------------------------
/**
* Constructs a new JMX MBean Proxy invocation handler.
*
* @param server reference to the MBean server this proxy connects to
* @param name object name of the MBean this proxy represents
*
* @throws MBeanProxyCreationException wraps underlying JMX exceptions in
* case the proxy creation fails
*/
public JMXInvocationHandler(MBeanServer server, ObjectName name)
throws MBeanProxyCreationException
{
try
{
if (server == null)
throw new MBeanProxyCreationException("null agent reference");
this.server = server;
this.objectName = name;
MBeanInfo info = server.getMBeanInfo(objectName);
MBeanAttributeInfo[] attributes = info.getAttributes();
MBeanOperationInfo[] operations = info.getOperations();
// collect the MBean attribute metadata for standard mbean proxies
for (int i = 0; i < attributes.length; ++i)
attributeMap.put(attributes[i].getName(), attributes[i]);
// Check whether the target resource exposes the common object methods.
// Dynamic Proxy will delegate these methods automatically to the
// invoke() implementation.
for (int i = 0; i < operations.length; ++i)
{
if (operations[i].getName().equals("toString") &&
operations[i].getReturnType().equals("java.lang.String") &&
operations[i].getSignature().length == 0)
{
delegateToStringToResource = true;
}
else if (operations[i].getName().equals("equals") &&
operations[i].getReturnType().equals(Boolean.TYPE.getName()) &&
operations[i].getSignature().length == 1 &&
operations[i].getSignature() [0].getType().equals("java.lang.Object"))
{
delegateEqualsToResource = true;
}
else if (operations[i].getName().equals("hashCode") &&
operations[i].getReturnType().equals(Integer.TYPE.getName()) &&
operations[i].getSignature().length == 0)
{
delegateHashCodeToResource = true;
}
}
}
catch (InstanceNotFoundException e)
{
throw new MBeanProxyCreationException("Object name " + name + " not found: " + e.toString());
}
catch (IntrospectionException e)
{
throw new MBeanProxyCreationException(e.toString());
}
catch (ReflectionException e)
{
throw new MBeanProxyCreationException(e.toString());
}
}
// InvocationHandler implementation ---------------------------
public Object invoke(Object proxy, Method method, Object[] args)
throws Exception
{
Class declaringClass = method.getDeclaringClass();
// Handle methods from Object class. If the target resource exposes
// operation metadata with same signature then the invocations will be
// delegated to the target. Otherwise this instance of invocation handler
// will execute them.
if (declaringClass == Object.class)
return handleObjectMethods(method, args);
// Check methods from ProxyContext interface. If invoked, delegate
// to the context implementation part of this invocation handler.
if (declaringClass == ProxyContext.class)
return method.invoke(this, args);
// Check methods from DynamicMBean interface. This allows the proxy
// to be used in cases where the underlying metadata has changed (a la
// Dynamic MBean).
if (declaringClass == DynamicMBean.class)
return handleDynamicMBeanInvocation(method, args);
try
{
String methodName = method.getName();
// Assume a get/setAttribute convention on the typed proxy interface.
// If the MBean metadata exposes a matching attribute then use the
// MBeanServer attribute accessors to read/modify the value. If not,
// fallback to MBeanServer.invoke() assuming this is an operation
// invocation despite the accessor naming convention.
// getter
if (methodName.startsWith("get") && args == null)
{
String attrName = methodName.substring(3, methodName.length());
// check that the metadata exists
MBeanAttributeInfo info = (MBeanAttributeInfo)attributeMap.get(attrName);
if (info != null)
{
String retType = method.getReturnType().getName();
// check for correct return type on the getter
if (retType.equals(info.getType()))
{
return server.getAttribute(objectName, attrName);
}
}
}
// boolean getter
else if (methodName.startsWith("is") && args == null)
{
String attrName = methodName.substring(2, methodName.length());
// check that the metadata exists
MBeanAttributeInfo info = (MBeanAttributeInfo)attributeMap.get(attrName);
if (info != null && info.isIs())
{
Class retType = method.getReturnType();
// check for correct return type on the getter
if (retType.equals(Boolean.class) || retType.equals(Boolean.TYPE))
{
return server.getAttribute(objectName, attrName);
}
}
}
// setter
else if (methodName.startsWith("set") && args != null && args.length == 1)
{
String attrName = methodName.substring(3, methodName.length());
// check that the metadata exists
MBeanAttributeInfo info = (MBeanAttributeInfo)attributeMap.get(attrName);
if (info != null && method.getReturnType().equals(Void.TYPE))
{
ClassLoader cl = Thread.currentThread().getContextClassLoader();
Class signatureClass = null;
String classType = info.getType();
if (isPrimitive(classType))
signatureClass = getPrimitiveClass(classType);
else
signatureClass = cl.loadClass(info.getType());
if (signatureClass.isAssignableFrom(args[0].getClass()))
{
server.setAttribute(objectName, new Attribute(attrName, args[0]));
return null;
}
}
}
String[] signature = null;
if (args != null)
{
signature = new String[args.length];
Class[] sign = method.getParameterTypes();
for (int i = 0; i < sign.length; ++i)
signature[i] = sign[i].getName();
}
return server.invoke(objectName, methodName, args, signature);
}
catch (InstanceNotFoundException e)
{
return getExceptionHandler().handleInstanceNotFound(this, e, method, args);
}
catch (AttributeNotFoundException e)
{
return getExceptionHandler().handleAttributeNotFound(this, e, method, args);
}
catch (InvalidAttributeValueException e)
{
return getExceptionHandler().handleInvalidAttributeValue(this, e, method, args);
}
catch (MBeanException e)
{
return getExceptionHandler().handleMBeanException(this, e, method, args);
}
catch (ReflectionException e)
{
return getExceptionHandler().handleReflectionException(this, e, method, args);
}
catch (RuntimeOperationsException e)
{
return getExceptionHandler().handleRuntimeOperationsException(this, e, method, args);
}
catch (RuntimeMBeanException e)
{
return getExceptionHandler().handleRuntimeMBeanException(this, e, method, args);
}
catch (RuntimeErrorException e)
{
return getExceptionHandler().handleRuntimeError(this, e, method, args);
}
}
public ProxyExceptionHandler getExceptionHandler()
{
return handler;
}
// ProxyContext implementation -----------------------------------
// The proxy provides an access point for the client to methods not part
// of the MBean's management interface. It can be used to configure the
// invocation (with context, client side interceptors, RPC), exception
// handling, act as an access point to MBean server interface and so on.
public void setExceptionHandler(ProxyExceptionHandler handler)
{
this.handler = handler;
}
public MBeanServer getMBeanServer()
{
return server;
}
public ObjectName getObjectName()
{
return objectName;
}
// Object overrides ----------------------------------------------
public String toString()
{
return "MBeanProxy for " + objectName + " (Agent ID: " + AgentID.get(server) + ")";
}
// Private -------------------------------------------------------
private Object handleObjectMethods(Method method, Object[] args)
throws InstanceNotFoundException, ReflectionException,
IntrospectionException, MBeanException
{
if (method.getName().equals("toString"))
{
if (delegateToStringToResource)
return server.invoke(objectName, "toString", null, null);
else
return toString();
}
else if (method.getName().equals("equals"))
{
if (delegateEqualsToResource)
{
return server.invoke(objectName, "equals",
new Object[] { args[0] },
new String[] { "java.lang.Object" }
);
}
else if (Proxy.isProxyClass(args[0].getClass()))
{
Proxy prxy = (Proxy)args[0];
return new Boolean(this.equals(Proxy.getInvocationHandler(prxy)));
}
else
{
return new Boolean(this.equals(args[0]));
}
}
else if (method.getName().equals("hashCode"))
{
if (delegateHashCodeToResource)
return server.invoke(objectName, "hashCode", null, null);
else
return new Integer(this.hashCode());
}
else throw new Error("Unexpected method invocation!");
}
private Object handleDynamicMBeanInvocation(Method method, Object[] args)
throws InstanceNotFoundException, ReflectionException,
IntrospectionException, MBeanException, AttributeNotFoundException,
InvalidAttributeValueException
{
String methodName = method.getName();
if (methodName.equals("setAttribute"))
{
server.setAttribute(objectName, (Attribute)args[0]);
return null;
}
else if (methodName.equals("setAttributes"))
return server.setAttributes(objectName, (AttributeList)args[0]);
else if (methodName.equals("getAttribute"))
return server.getAttribute(objectName, (String)args[0]);
else if (methodName.equals("getAttributes"))
return server.getAttributes(objectName, (String[])args[0]);
else if (methodName.equals("invoke"))
return server.invoke(objectName, (String)args[0], (Object[])args[1], (String[])args[2]);
else if (methodName.equals("getMBeanInfo"))
return server.getMBeanInfo(objectName);
else throw new Error("Unexpected method invocation!");
}
private boolean isPrimitive(String type)
{
if (type.equals(Integer.TYPE.getName())) return true;
if (type.equals(Long.TYPE.getName())) return true;
if (type.equals(Boolean.TYPE.getName())) return true;
if (type.equals(Byte.TYPE.getName())) return true;
if (type.equals(Character.TYPE.getName())) return true;
if (type.equals(Short.TYPE.getName())) return true;
if (type.equals(Float.TYPE.getName())) return true;
if (type.equals(Double.TYPE.getName())) return true;
if (type.equals(Void.TYPE.getName())) return true;
return false;
}
private Class getPrimitiveClass(String type)
{
if (type.equals(Integer.TYPE.getName())) return Integer.TYPE;
if (type.equals(Long.TYPE.getName())) return Long.TYPE;
if (type.equals(Boolean.TYPE.getName())) return Boolean.TYPE;
if (type.equals(Byte.TYPE.getName())) return Byte.TYPE;
if (type.equals(Character.TYPE.getName()))return Character.TYPE;
if (type.equals(Short.TYPE.getName())) return Short.TYPE;
if (type.equals(Float.TYPE.getName())) return Float.TYPE;
if (type.equals(Double.TYPE.getName())) return Double.TYPE;
if (type.equals(Void.TYPE.getName())) return Void.TYPE;
return null;
}
}
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