JMX简介

JMX(Java Management Extensions)是一个为应用程序植入管理功能的框架。JMX是一套标准的代理和服务，实际上，用户可以在任何Java应用程序中使用这些代理和服务实现管理。这是官方文档上的定义，我看过很多次也无法很好的理解。我个人的理解是JMX让程序有被管理的功能，例如你开发一个WEB网站，它是在24小时不间断运行，那么你肯定会对网站进行监控，如每天的UV、PV是多少；又或者在业务高峰的期间，你想对接口进行限流，就必须去修改接口并发的配置值。

 JMX架构图

 

 

案例：

Mbean

package com.hpe.jmx;//MBean接口public interface HelloMBean {    public String getName();    public void setName(String name);    public String getAge();    public void setAge(String age);    public String helloWorld();    public void helloWorld(String str);    public void getTelephone();}

package com.hpe.jmx;import java.security.PublicKey;//Mbean的实现public class Hello implements HelloMBean {    private String name;    private String age;    public Hello(String name,String age){        this.name = name;        this.age = age;    }    public void getTelephone() {        System.out.println("get Telephone");    }    public String helloWorld() {        System.out.println("hello world");        return "gaojy";    }    public void helloWorld(String str) {        System.out.println("helloWorld:" + str);    }    public String getName() {        System.out.println("get name 123");        return name;    }    public void setName(String name) {        System.out.println("set name 123");        this.name = name;    }    public String getAge() {        System.out.println("get age 123");        return age;    }    public void setAge(String age) {        System.out.println("set age 123");        this.age = age;    }}

适配层：MBeanServer，主要是提供对资源的注册和管理。

接入层：提供远程访问的入口。

package com.hpe.jmx;import java.lang.management.ManagementFactory;import java.rmi.registry.LocateRegistry;import javax.management.JMException;import javax.management.MBeanServer;import javax.management.ObjectName;import javax.management.remote.JMXConnectorServer;import javax.management.remote.JMXConnectorServerFactory;import javax.management.remote.JMXServiceURL;public class helloAgent {    public static void main(String[] args) throws JMException, Exception {        //适配层        MBeanServer server = ManagementFactory.getPlatformMBeanServer();        ObjectName helloName = new ObjectName("jmxBean:name=hello");        // create mbean and register mbean        //创建并注册Mbean        server.registerMBean(new Hello("gaojy","24"), helloName); try { //这个步骤很重要，注册一个端口，绑定url后用于客户端通过rmi方式连接JMXConnectorServer LocateRegistry.createRegistry(9999); // URL路径的结尾可以随意指定，但如果需要用Jconsole来进行连接，则必须使用jmxrmi JMXServiceURL url = new JMXServiceURL ("service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi"); JMXConnectorServer jcs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, server); System.out.println("begin rmi start"); jcs.start(); System.out.println("rmi start"); } catch (Exception e) { // TODO: handle exception  } Thread.sleep(60 * 60 * 1000); } }

 

客户端：

package com.hpe.jmx;import java.io.IOException;import java.net.MalformedURLException;import javax.management.Attribute;import javax.management.AttributeNotFoundException;import javax.management.InstanceNotFoundException;import javax.management.InvalidAttributeValueException;import javax.management.MBeanException;import javax.management.MBeanServerConnection;import javax.management.MBeanServerInvocationHandler;import javax.management.MalformedObjectNameException;import javax.management.ObjectName;import javax.management.ReflectionException;import javax.management.remote.JMXConnector;import javax.management.remote.JMXConnectorFactory;import javax.management.remote.JMXServiceURL;public class Client {    public static void main(String[] args) throws Exception {        JMXServiceURL url = new JMXServiceURL(                "service:jmx:rmi:///jndi/rmi://localhost:9999/jmxrmi");        JMXConnector jmxc = JMXConnectorFactory.connect(url, null);        MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();        // ObjectName的名称与前面注册时候的保持一致        ObjectName mbeanName = new ObjectName("jmxBean:name=hello");        System.out.println("Domains ......");        String[] domains = mbsc.getDomains();        for (int i = 0; i < domains.length; i++) {            System.out.println("doumain[" + i + "]=" + domains[i]);        }        System.out.println("MBean count = " + mbsc.getMBeanCount());        // 设置指定Mbean的特定属性值        // 这里的setAttribute、getAttribute操作只能针对bean的属性        // 例如对getName或者setName进行操作，只能使用Name，需要去除方法的前缀        mbsc.setAttribute(mbeanName, new Attribute("Name", "杭州"));// 远程设置        mbsc.setAttribute(mbeanName, new Attribute("Age", "1990"));        String age = (String) mbsc.getAttribute(mbeanName, "Age"); // 远程获取        String name = (String) mbsc.getAttribute(mbeanName, "Name");        System.out.println("age=" + age + ";name=" + name);        // 远程方法调用        HelloMBean proxy = MBeanServerInvocationHandler.newProxyInstance(mbsc,                mbeanName, HelloMBean.class, false);        proxy.helloWorld();        proxy.helloWorld("migu");        proxy.getTelephone();        // invoke调用bean的方法，只针对非设置属性的方法        // 例如invoke不能对getName方法进行调用        mbsc.invoke(mbeanName, "getTelephone", null, null);        mbsc.invoke(mbeanName, "helloWorld",                new String[] { "I'll connect to JMX Server via client2" },                new String[] { "java.lang.String" });        mbsc.invoke(mbeanName, "helloWorld", null, null);    }}

 

参考