Druid/src/main/java/com/alibaba/druid/util/JMXUtils.java

/*
 * Copyright 2011 Alibaba Group.
 *
 * 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 com.alibaba.druid.util;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.lang.management.ManagementFactory;
import java.util.HashMap;
import java.util.Map;

import javax.management.InstanceAlreadyExistsException;
import javax.management.JMException;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.management.openmbean.CompositeData;
import javax.management.openmbean.CompositeDataSupport;
import javax.management.openmbean.CompositeType;
import javax.management.openmbean.OpenType;
import javax.management.openmbean.SimpleType;

/**
 * 
 * @author wenshao<szujobs@hotmail.com>
 *
 */
public final class JMXUtils {
	public static ObjectName register(String name, Object mbean) {
		try {
			ObjectName objectName = new ObjectName(name);

			MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();

			try {
				mbeanServer.registerMBean(mbean, objectName);
			} catch (InstanceAlreadyExistsException ex) {
				mbeanServer.unregisterMBean(objectName);
				mbeanServer.registerMBean(mbean, objectName);
			}
			
			return objectName;
		} catch (JMException e) {
			throw new IllegalArgumentException(name, e);
		}
	}

	public static void unregister(String name) {
		try {
			MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();

			mbeanServer.unregisterMBean(new ObjectName(name));
		} catch (JMException e) {
			throw new IllegalArgumentException(name, e);
		}

	}
	
	private static final String[] THROWABLE_COMPOSITE_INDEX_NAMES = { "message", "class", "stackTrace" };
	private static final String[] THROWABLE_COMPOSITE_INDEX_DESCRIPTIONS = { "message", "class", "stackTrace" };
	private static final OpenType<?>[] THROWABLE_COMPOSITE_INDEX_TYPES = new OpenType<?>[] { SimpleType.STRING, SimpleType.STRING, SimpleType.STRING };
	
	private static CompositeType THROWABLE_COMPOSITE_TYPE = null;

	public static CompositeType getThrowableCompositeType() throws JMException {
		if (THROWABLE_COMPOSITE_TYPE == null) {
			THROWABLE_COMPOSITE_TYPE = new CompositeType("Throwable", "Throwable", THROWABLE_COMPOSITE_INDEX_NAMES, THROWABLE_COMPOSITE_INDEX_DESCRIPTIONS,
					THROWABLE_COMPOSITE_INDEX_TYPES);
		}

		return THROWABLE_COMPOSITE_TYPE;
	}

	public static CompositeData getErrorCompositeData(Throwable error) throws JMException {
		if (error == null) {
			return null;
		}

		Map<String, Object> map = new HashMap<String, Object>();

		map.put("class", error.getClass().getName());
		map.put("message", error.getMessage());

		StringWriter buf = new StringWriter();
		error.printStackTrace(new PrintWriter(buf));

		map.put("stackTrace", buf.toString());

		return new CompositeDataSupport(getThrowableCompositeType(), map);
	}
}