donaldp 2002/09/13 04:29:13
Added: baxter/src/java/org/apache/excalibur/baxter
MBeanInvocationHandler.java
Log:
Add an invocation handler for MBeans. This handler will allow you to proxy MBeans as
long as they implement all methods in an interface (or set of interfaces)
Revision Changes Path
1.1
jakarta-avalon-excalibur/baxter/src/java/org/apache/excalibur/baxter/MBeanInvocationHandler.java
Index: MBeanInvocationHandler.java
===================================================================
/*
* Copyright (C) The Apache Software Foundation. All rights reserved.
*
* This
software is published under the terms of the Apache Software License
* version 1.1, a
copy of which has been included with this distribution in
* the LICENSE.txt file.
*/
package org.apache.excalibur.baxter;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import
java.util.HashMap;
import java.util.Map;
import javax.management.MBeanServer;
import
javax.management.ObjectName;
import javax.management.InstanceNotFoundException;
import
javax.management.MBeanException;
import javax.management.ReflectionException;
/**
*
An {@link InvocationHandler} for MBeans.
* Allows you to invoke MBean as if they were
normal objects if
* they implement all the methods in an interface.
*
* @author <a
href="mailto:peter at apache.org">Peter Donald</a>
* @version CVS $Revision: 1.1 $
$Date: 2002/09/13 11:29:13 $
*/
public class MBeanInvocationHandler
implements
InvocationHandler
{
/**
* Map of methods onto parameter type arrays.
*/
private final Map m_methodMap = new HashMap();
/**
* The MBeanServer to
call methods on.
*/
private final MBeanServer m_mBeanServer;
/**
*
The name of object we are to invoke.
*/
private final ObjectName
m_objectName;
/**
* Create a Proxy for MBean that implements specified
* interfaces. It is expected that the MBean as registered
* will have all of
those methods implemented.
*
* @param mBeanServer the MBeanServer
*
@param objectName the name of object
* @param services the service interfaces to
proxy
* @return the proxied MBean
*/
public static Object createProxy(
final MBeanServer mBeanServer,
final ObjectName
objectName,
final Class[] services )
{
final ClassLoader classLoader =
MBeanInvocationHandler.class.getClassLoader();
final MBeanInvocationHandler
handler =
new MBeanInvocationHandler( mBeanServer, objectName );
return Proxy.newProxyInstance( classLoader, services, handler );
}
/**
*
Create InvocationHandler for specified
* ObjectName on specified MBeanServer.
*
* @param mBeanServer the MBeanServer
* @param objectName the name of
object
*/
public MBeanInvocationHandler( final MBeanServer mBeanServer,
final ObjectName objectName )
{
if( null ==
mBeanServer )
{
throw new NullPointerException( "mBeanServer" );
}
if( null == objectName )
{
throw new
NullPointerException( "objectName" );
}
m_mBeanServer = mBeanServer;
m_objectName = objectName;
}
/**
* Return the MBeanServer the
InvocationHandler calls methods using.
*
* @return the MBeanServer the
InvocationHandler calls methods using.
*/
protected MBeanServer
getMBeanServer()
{
return m_mBeanServer;
}
/**
* Return the
ObjectName designating object to call methods on.
*
* @return the ObjectName
designating object to call methods on.
*/
protected ObjectName
getObjectName()
{
return m_objectName;
}
/**
* Invoke a
method on a MBean.
*/
public Object invoke( final Object proxy,
final Method method,
final Object[] args )
throws Throwable
{
final String[] paramTypes = getParamTypes( method );
try
{
return getMBeanServer().invoke( getObjectName(),
method.getName(),
args,
paramTypes );
}
catch( InstanceNotFoundException e )
{
throw new
IllegalStateException( e.toString() );
}
catch( MBeanException e )
{
throw e.getTargetException();
}
catch(
ReflectionException e )
{
throw new IllegalStateException(
e.toString() );
}
}
/**
* Get a list of param types for method.
*/
private synchronized String[] getParamTypes( final Method method )
{
String[] paramTypes = (String[])m_methodMap.get( method );
if( null ==
paramTypes )
{
paramTypes = calcParamTypes( method );
m_methodMap.put( method, paramTypes );
}
return paramTypes;
}
/**
* Create a list of strings that name types
* of a methods parameters.
This is derived from
* method object.
*/
private String[]
calcParamTypes( final Method method )
{
final Class[] parameterClasses =
method.getParameterTypes();
final String[] paramTypes = new String[
parameterClasses.length ];
for( int i = 0; i < paramTypes.length; i++ )
{
paramTypes[ i ] = parameterClasses[ i ].getName();
}
return paramTypes;
}
}
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
