JMX学习笔记(三)-MXBean

在MBean中有只要遵循以下两个规则，我们就可以在jconsole中动态的改变MBean中的属性值

1. JMX中要定义接口必须以xxxMBean的规范定义

2. 得有类实现xxxMBean接口

例如：

package com.dxz.mbean.demo3;

public interface ServerConfigureMBean {

    public int getPort();

    public void setPort(int port);

    public String getHost();

    public void setHost(String host);

    public int getMaxThread();

    public void setMaxThread(int maxThread);

    public int getMinThread();

    public void setMinThread(int minThread);

}

接着实现这个MBean：

package com.dxz.mbean.demo3;

public class ServerConfigure implements ServerConfigureMBean {
    private int port;

    private String host;

    private int maxThread;

    private int minThread;

    public ServerConfigure(int port, String host, int maxThread, int minThread) {
        this.port = port;
        this.host = host;
        this.maxThread = maxThread;
        this.minThread = minThread;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public String getHost() {
        return host;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public int getMaxThread() {
        return maxThread;
    }

    public void setMaxThread(int maxThread) {
        this.maxThread = maxThread;
    }

    public int getMinThread() {
        return minThread;
    }

    public void setMinThread(int minThread) {
        this.minThread = minThread;
    }

}

测试：

package com.dxz.mbean.demo3;

import java.lang.management.ManagementFactory;

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

public class ServerTest {

    public static void main(String[] args) throws Exception {
        testServerConfigureMBean();
    }

    public static void testServerConfigureMBean() throws Exception {
        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();

        ServerConfigure serverConfigure = new ServerConfigure(8080, "china.com", 20, 100);

        ObjectName serverName = new ObjectName("com.dxz.mbean.demo3:type=ServerConfigure");
        mbs.registerMBean(serverConfigure, serverName);
        System.out.println("Waiting...");
        Thread.sleep(Long.MAX_VALUE);
    }

}

打开jconsole：

但是以上这些ServerConfigure的属性都是基本类型，包含在Java.lang.*里，设想，如果说jconsole在类外一个远端的jvm上，如果这里的属性是一个自定义对象，远端的jvm可能不知道该类型的对象：

修改上边的ServerConfigre，使他成为一个聚合对象，去掉ServerConfigureMBean接口实现：

测试结果,打开jconsole查看：

为了让与远端JVM认识该对象，我们需要将ServerMbean改为ServerMXBean，并使用java.beans.ConstructorProperties注解告诉JVM怎样组装该对象：

package com.dxz.mbean.demo5;

public interface ServerMXBean {
    public ServerConfigure getServerConfigure();   

    public void setServerConfigure(ServerConfigure serverConfigure);   

    public void defaultServerConfigure();
}

1. 使用java.beans.ConstructorProperties注解：

package com.dxz.mbean.demo5;

import java.beans.ConstructorProperties;

public class ServerConfigure {

    private int port;

    private String host;

    private int maxThread;

    private int minThread;

    /**
     * 加入@ConstructorProperties注解
     */
    @ConstructorProperties({ "port", "host", "maxThread", "minThread" }) //如果没有会报错，Caused by: java.io.InvalidObjectException: Do not know how to make a com.dxz.mbean.demo5.ServerConfigure from a CompositeData: no method from(CompositeData); no constructor has @ConstructorProperties annotation; does not have a public no-arg constructor; not an interface
    public ServerConfigure(int port, String host, int maxThread, int minThread) {
        this.port = port;
        this.host = host;
        this.maxThread = maxThread;
        this.minThread = minThread;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public String getHost() {
        return host;
    }

    public void setHost(String host) {
        this.host = host;
    }

    public int getMaxThread() {
        return maxThread;
    }

    public void setMaxThread(int maxThread) {
        this.maxThread = maxThread;
    }

    public int getMinThread() {
        return minThread;
    }

    public void setMinThread(int minThread) {
        this.minThread = minThread;
    }

}

package com.dxz.mbean.demo5;

public class Server implements ServerMXBean {

    /**
     * 封装
     */
    private ServerConfigure serverConfigure;

    public Server(ServerConfigure serverConfigure) {
        this.serverConfigure = serverConfigure;
    }

    @Override
    public ServerConfigure getServerConfigure() {
        synchronized (serverConfigure) {
            return this.serverConfigure;
        }
    }

    @Override
    public void setServerConfigure(ServerConfigure serverConfigure) {
        synchronized (serverConfigure) {
            this.serverConfigure = serverConfigure;
        }
    }

    @Override
    public void defaultServerConfigure() {
        synchronized (serverConfigure) {
            serverConfigure.setPort(80);
            serverConfigure.setHost("www.haitao.com");
            serverConfigure.setMinThread(10);
            serverConfigure.setMaxThread(500);
        }
    }

}

package com.dxz.mbean.demo5;

import java.lang.management.ManagementFactory;

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

public class ServerTest {
    public static void main(String[] args) throws Exception {
        testServerMBean();
    }   

    public static void testServerMBean() throws Exception {
        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();   

        ServerConfigure serverConfigure = new ServerConfigure(8080,
                "www.china5.com", 20, 100);   

        Server server = new Server(serverConfigure);   

        ObjectName serverName = new ObjectName(
                "com.dxz.mbean.demo5:type=Server");
        mbs.registerMBean(server, serverName);
        System.out.println("Waiting...");
        Thread.sleep(Long.MAX_VALUE);
    }
}

测试代码一样，就不再重复，最后运行测试，查看jconsole：

双击值，我们将会看到：

实际上MXBean的概念很简单，就是定义xxxMXBean接口，然后实现这个接口，与MBean类似，为了阐述这个MXBean与MBean的不同才列出这么多代码，希望大家能理解：）