MBeanTyper.java Source code

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Here is the source code for MBeanTyper.java

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/*
 * JBoss, Home of Professional Open Source.
 * 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.
 */

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.management.MBeanException;
import javax.management.MBeanServer;
import javax.management.ObjectName;

/**
 * MBeanTyper is a helper class that creates a typed-object from an MBean
 * ObjectName and a main interface class that the MBean implements. You can then
 * use the returned object (casted to the appropriate main interface class) with
 * the correct typed signatures instead of
 * <tt>mbeanserver.invoke(objectname,<sig>,etc.)</tt>.
 * <P>
 * Example usage: <BR>
 * <code><tt>
 *      MyInterfaceMBean mbean=(MyInterfaceMBean)MBeanTyper.typeMBean(server,new ObjectName(":type=MyBean"),MyInterfaceMBean.class);
 *      mbean.foobar();
 * </tt></code>
 * <P>
 * 
 * To turn debug on for this package, set the System property
 * <tt>vocalos.jmx.mbeantyper.debug</tt> to true.
 * 
 * @author <a href="mailto:jhaynie@vocalocity.net">Jeff Haynie</a>
 */
class MBeanTyper {
    static final boolean DEBUG = Boolean.getBoolean("jboss.jmx.debug");

    /**
     * create a typed object from an mbean
     */
    public static final Object typeMBean(MBeanServer server, ObjectName mbean, Class mainInterface)
            throws Exception {
        List interfaces = new ArrayList();
        if (mainInterface.isInterface()) {
            interfaces.add(mainInterface);
        }
        addInterfaces(mainInterface.getInterfaces(), interfaces);
        Class cl[] = (Class[]) interfaces.toArray(new Class[interfaces.size()]);
        if (DEBUG) {
            System.err
                    .println("typeMean->server=" + server + ",mbean=" + mbean + ",mainInterface=" + mainInterface);
            for (int c = 0; c < cl.length; c++) {
                System.err.println("     :" + cl[c]);
            }
        }

        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), cl,
                new MBeanTyperInvoker(server, mbean));
    }

    private static final void addInterfaces(Class cl[], List list) {
        if (cl == null)
            return;
        for (int c = 0; c < cl.length; c++) {
            list.add(cl[c]);
            addInterfaces(cl[c].getInterfaces(), list);
        }
    }
}

/**
 * MBeanTyperInvoker handles method invocations against the MBeanTyper target
 * object and forwards them to the MBeanServer and ObjectName for invocation.
 * 
 * @author <a href="mailto:jhaynie@vocalocity.net">Jeff Haynie</a>
 */
final class MBeanTyperInvoker implements java.lang.reflect.InvocationHandler {
    private final MBeanServer server;

    private final ObjectName mbean;

    private final Map signatureCache = Collections.synchronizedMap(new HashMap());

    MBeanTyperInvoker(MBeanServer server, ObjectName mbean) {
        this.server = server;
        this.mbean = mbean;
    }

    private boolean isJMXAttribute(Method m) {
        String name = m.getName();
        return (name.startsWith("get"));

    }

    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        if (MBeanTyper.DEBUG) {
            System.err.println("  ++ method=" + method.getName() + ",args=" + args);
        }
        try {
            if (method.getDeclaringClass() == Object.class) {
                String name = method.getName();
                if (name.equals("hashCode")) {
                    return new Integer(this.hashCode());
                } else if (name.equals("toString")) {
                    return this.toString();
                } else if (name.equals("equals")) {
                    // FIXME: this needs to be reviewed - we should be
                    // smarter about this ...
                    return new Boolean(equals(args[0]));
                }
            } else if (isJMXAttribute(method) && (args == null || args.length <= 0)) {
                String name = method.getName().substring(3);
                return server.getAttribute(mbean, name);
            }

            String sig[] = (String[]) signatureCache.get(method);
            if (sig == null) {
                // get the method signature from the method argument directly
                // vs. the arguments passed, since there may be primitives that
                // are wrapped as objects in the arguments
                Class _args[] = method.getParameterTypes();
                if (_args != null && _args.length > 0) {
                    sig = new String[_args.length];
                    for (int c = 0; c < sig.length; c++) {
                        if (_args[c] != null) {
                            sig[c] = _args[c].getName();
                        }
                    }
                } else {
                    sig = new String[0];
                }
                signatureCache.put(method, sig);
            }
            return server.invoke(mbean, method.getName(), args, sig);
        } catch (Throwable t) {
            if (MBeanTyper.DEBUG) {
                t.printStackTrace();
            }
            if (t instanceof UndeclaredThrowableException) {
                UndeclaredThrowableException ut = (UndeclaredThrowableException) t;
                throw ut.getUndeclaredThrowable();
            } else if (t instanceof InvocationTargetException) {
                InvocationTargetException it = (InvocationTargetException) t;
                throw it.getTargetException();
            } else if (t instanceof MBeanException) {
                MBeanException me = (MBeanException) t;
                throw me.getTargetException();
            } else {
                throw t;
            }
        }
    }
}