JMX动态MBean示例

  JMX管理构件（MBean）分为四种形式，分别是标准管理构件（Standard MBean）、动态管理构件（Dynamic MBean）、开放管理构件(Open Mbean)和模型管理构件(Model MBean)。本文即是对动态管理构件（Dynamic MBean）的演示说明。

  动态管理构件的最大的特点是可以在运行期暴露自己的管理接口，因此具有更好的灵活性。它的实现是通过实现一个特定的接口DynamicMBean。

 示例参照http://bluestar.iteye.com/blog/58083实现，小作修改，写在此处只为方面查阅。

 

HelloDynamic，实现了DynamicMBean接口的管理控件(Mbean)

 

package com.jmxdemo.dynamic;

import java.lang.reflect.Constructor;

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.ReflectionException;

public class HelloDynamic implements DynamicMBean {
	// 管理控件（MBean）属性
	private String name;

	// 动态创建MBean需要的变量
	private String className = this.getClass().getName();
	private String description = "Simple implementation of a dynamic MBean.";

	private MBeanAttributeInfo[] attributes;
	private MBeanConstructorInfo[] constructors;
	private MBeanOperationInfo[] operations;
	private MBeanInfo mBeanInfo;
	private MBeanNotificationInfo[] notifications;

	public HelloDynamic() {
		init();
		buildDynamicMBean();
	}

	private void init() {
		className = this.getClass().getName();
		description = "Simple implementation of a dynamic MBean.";
		attributes = new MBeanAttributeInfo[1];
		constructors = new MBeanConstructorInfo[1];
		operations = new MBeanOperationInfo[1];
		notifications = new MBeanNotificationInfo[0];
	}

	private void buildDynamicMBean() {
		// constructors
		Constructor<?>[] ctors = this.getClass().getConstructors();
		constructors[0] = new MBeanConstructorInfo(
				"HelloDynamic(): Constructs a HelloDynamic object", ctors[0]);
		// attributes
		attributes[0] = new MBeanAttributeInfo("name", "java.lang.String",
				"Name: name string", true, true, false);
		// methods
		MBeanParameterInfo[] params = null;
		operations[0] = new MBeanOperationInfo("print",
				"print(): print the name", params, "void",
				MBeanOperationInfo.INFO);
		// MBeanInfo
		mBeanInfo = new MBeanInfo(this.className, description, attributes,
				constructors, operations, notifications);
	}

	@Override
	public Object getAttribute(String attribute)
			throws AttributeNotFoundException, MBeanException,
			ReflectionException {
		if (attribute == null) {
			return null;
		}
		if ("name".equals(attribute)) {
			return name;
		}
		return null;
	}

	@Override
	public AttributeList getAttributes(String[] attributes) {
		if (attributes == null) {
			return null;
		}
		AttributeList reslist = new AttributeList();

		for (String attr : attributes) {
			try {
				Object value = getAttribute(attr);
				reslist.add(new Attribute(attr, value));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		return reslist;
	}

	@Override
	public MBeanInfo getMBeanInfo() {
		return mBeanInfo;
	}

	@Override
	public Object invoke(String actionName, Object[] params, String[] signature)
			throws MBeanException, ReflectionException {
		if (actionName.equals("print")) {
			print();
		} else if("dynamicPrint".equals(actionName)) {
			dynamicPrint();
		}
		return null;
	}

	@Override
	public void setAttribute(Attribute attribute)
			throws AttributeNotFoundException, InvalidAttributeValueException,
			MBeanException, ReflectionException {
		if (attribute == null) {
			return;
		}

		String attrname = attribute.getName();
		Object attrvalue = attribute.getValue();

		if ("name".equals(attrname)) {
			if (attrvalue == null) {
				name = null;
			} else
				try {
					if (Class.forName("java.lang.String").isAssignableFrom(
							attrvalue.getClass())) {
						name = (String) attrvalue;
					}
				} catch (ClassNotFoundException e) {
					e.printStackTrace();
				}
		}

	}

	@Override
	public AttributeList setAttributes(AttributeList attributes) {
		if (attributes == null) {
			return null;
		}
		AttributeList reslist = new AttributeList();
		for (Object obj : attributes) {
			Attribute attr = (Attribute) obj;
			try {
				setAttribute(attr);
				String attrname = attr.getName();
				Object attrvalue = attr.getValue();
				reslist.add(new Attribute(attrname, attrvalue));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return reslist;
	}

	private void print() {
		System.out.println("Hello " + name + ", This is helloDynamic");
		// add method dynamic at runtime
		operations = new MBeanOperationInfo[2];
		buildDynamicMBean();
		MBeanParameterInfo[] parameters = null;
		operations[1] = new MBeanOperationInfo("dynamicPrint",
				"dynamicPrint: Runtime generated by print method", parameters,
				"void", MBeanOperationInfo.INFO);
	}

	private void dynamicPrint() {
		System.out.println("This is a runtime generated method!");
	}
}

  

 

HelloDynamicAgent.java

 

package com.jmxdemo.dynamic;

import javax.management.InstanceAlreadyExistsException;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.MalformedObjectNameException;
import javax.management.NotCompliantMBeanException;
import javax.management.ObjectName;

import com.sun.jdmk.comm.HtmlAdaptorServer;

public class HelloDynamicAgent {
	private static String DOMAIN = "MyDynamicMBean";
	/**
	 * @param args
	 * @throws NullPointerException 
	 * @throws MalformedObjectNameException 
	 * @throws NotCompliantMBeanException 
	 * @throws MBeanRegistrationException 
	 * @throws InstanceAlreadyExistsException 
	 */
	public static void main(String[] args) throws MalformedObjectNameException, NullPointerException, InstanceAlreadyExistsException, MBeanRegistrationException, NotCompliantMBeanException {
		//创建一个MBean服务对象，DOMAIN类似于java里面的公共package部分
		MBeanServer server = MBeanServerFactory.createMBeanServer(DOMAIN);
		//创建DynamicMBean对象
		HelloDynamic hello = new HelloDynamic();
		//创建一个web适配器服务器，表示我们MBean服务通过web形式来提供给用户管理
		HtmlAdaptorServer htmlserver = new HtmlAdaptorServer();
		htmlserver.setPort(9999);
		//ObjctName对象类似于完整的package
		ObjectName helloname = new ObjectName(DOMAIN + ":name=HelloDynamic");
		ObjectName htmlname = new ObjectName(DOMAIN + ":name=HtmlAdaptor");
		server.registerMBean(hello, helloname);
		server.registerMBean(htmlserver, htmlname);
		
		htmlserver.start();
	}

}

   

 

运行程序，打开浏览器，输入http://localhost:9999，即可访问管理页面，页面下方点击name=HelloDynamic，进入MBean View，然后再操作中点击print方法，再次回到MBean View页面你会发现多了一个dynamicPrint方法，这个方法就是我们进行print操作时动态生成的。

 

 

 

 

评论

1 楼 sswh 2013-11-27  

没有感觉 动态MBean有什么实际的用处？