import java.lang.management.ClassLoadingMXBean;

import java.lang.management.CompilationMXBean;

import java.lang.management.GarbageCollectorMXBean;

import java.lang.management.ManagementFactory;

import java.lang.management.MemoryMXBean;

import java.lang.management.MemoryManagerMXBean;

import java.lang.management.MemoryPoolMXBean;

import java.lang.management.MemoryUsage;

import java.lang.management.OperatingSystemMXBean;

import java.lang.management.RuntimeMXBean;

import java.lang.management.ThreadMXBean;

import java.util.List;

import javax.management.MBeanServerConnection;

public class MBeanDemo {

    public static void main(String[] args) {

        showJvmInfo();

        showMemoryInfo();

        showSystem();

        showClassLoading();

        showCompilation();

        showThread();

        showGarbageCollector();

        showMemoryManager();

        showMemoryPool();

    }

    /**

     * Java 虚拟机的运行时系统

     */

    public static void showJvmInfo() {

        RuntimeMXBean mxbean = ManagementFactory.getRuntimeMXBean();

        String vendor = mxbean.getVmVendor();

        System.out.println("jvm name:" + mxbean.getVmName());

        System.out.println("jvm version:" + mxbean.getVmVersion());

        System.out.println("jvm bootClassPath:" + mxbean.getBootClassPath());

        System.out.println("jvm start time:" + mxbean.getStartTime());

    }

    /**

     * Java 虚拟机的内存系统

     */

    public static void showMemoryInfo() {

        MemoryMXBean mem = ManagementFactory.getMemoryMXBean();

        MemoryUsage heap = mem.getHeapMemoryUsage();

        System.out.println("Heap committed:" + heap.getCommitted() + " init:" + heap.getInit() + " max:"

                           + heap.getMax() + " used:" + heap.getUsed());

    }

    /**

     * Java 虚拟机在其上运行的操作系统

     */

    public static void showSystem() {

        OperatingSystemMXBean op = ManagementFactory.getOperatingSystemMXBean();

        System.out.println("Architecture: " + op.getArch());

        System.out.println("Processors: " + op.getAvailableProcessors());

        System.out.println("System name: " + op.getName());

        System.out.println("System version: " + op.getVersion());

        System.out.println("Last minute load: " + op.getSystemLoadAverage());

    }

    /**

     * Java 虚拟机的类加载系统

     */

    public static void showClassLoading(){

        ClassLoadingMXBean cl = ManagementFactory.getClassLoadingMXBean();

        System.out.println("TotalLoadedClassCount: " + cl.getTotalLoadedClassCount());

        System.out.println("LoadedClassCount" + cl.getLoadedClassCount());

        System.out.println("UnloadedClassCount:" + cl.getUnloadedClassCount());

    }

    /**

     * Java 虚拟机的编译系统

     */

    public static void showCompilation(){

        CompilationMXBean com = ManagementFactory.getCompilationMXBean();

        System.out.println("TotalCompilationTime:" + com.getTotalCompilationTime());

        System.out.println("name:" + com.getName());

    }

    /**

     * Java 虚拟机的线程系统

     */

    public static void showThread(){

        ThreadMXBean thread = ManagementFactory.getThreadMXBean();

        System.out.println("ThreadCount" + thread.getThreadCount());

        System.out.println("AllThreadIds:" + thread.getAllThreadIds());

        System.out.println("CurrentThreadUserTime" + thread.getCurrentThreadUserTime());

        //......还有其他很多信息

    }

    /**

     * Java 虚拟机中的垃圾回收器。

     */

    public static void showGarbageCollector(){

        List<GarbageCollectorMXBean> gc = ManagementFactory.getGarbageCollectorMXBeans();

        for(GarbageCollectorMXBean GarbageCollectorMXBean : gc){

            System.out.println("name:" + GarbageCollectorMXBean.getName());

            System.out.println("CollectionCount:" + GarbageCollectorMXBean.getCollectionCount());

            System.out.println("CollectionTime" + GarbageCollectorMXBean.getCollectionTime());

        }

    }

    /**

     * Java 虚拟机中的内存管理器

     */

    public static void showMemoryManager(){

        List<MemoryManagerMXBean> mm = ManagementFactory.getMemoryManagerMXBeans();

        for(MemoryManagerMXBean eachmm: mm){

            System.out.println("name:" + eachmm.getName());

            System.out.println("MemoryPoolNames:" + eachmm.getMemoryPoolNames().toString());

        }

    }

    /**

     * Java 虚拟机中的内存池

     */

    public static void showMemoryPool(){

        List<MemoryPoolMXBean> mps = ManagementFactory.getMemoryPoolMXBeans();

        for(MemoryPoolMXBean mp : mps){

            System.out.println("name:" + mp.getName());

            System.out.println("CollectionUsage:" + mp.getCollectionUsage());

            System.out.println("type:" + mp.getType());

        }

    }

    /**

     * 访问 MXBean 的方法的三种方法

     */

    public static void visitMBean(){

        //第一种直接调用同一 Java 虚拟机内的 MXBean 中的方法。

        RuntimeMXBean mxbean = ManagementFactory.getRuntimeMXBean();

        String vendor1 = mxbean.getVmVendor();

        System.out.println("vendor1:" + vendor1);

        //第二种通过一个连接到正在运行的虚拟机的平台 MBeanServer 的 MBeanServerConnection。

        MBeanServerConnection mbs = null;

        // Connect to a running JVM (or itself) and get MBeanServerConnection

        // that has the JVM MXBeans registered in it

        /*

        try {

            // Assuming the RuntimeMXBean has been registered in mbs

            ObjectName oname = new ObjectName(ManagementFactory.RUNTIME_MXBEAN_NAME);

            String vendor2 = (String) mbs.getAttribute(oname, "VmVendor");

            System.out.println("vendor2:" + vendor2);

        } catch (Exception e) {

            e.printStackTrace();

        }

        */

        //第三种使用 MXBean 代理

//        MBeanServerConnection mbs3 = null;

//        RuntimeMXBean proxy;

//        try {

//            proxy = ManagementFactory.newPlatformMXBeanProxy(mbs3,ManagementFactory.RUNTIME_MXBEAN_NAME,

//                                                     RuntimeMXBean.class);

//            String vendor = proxy.getVmVendor();

//        } catch (IOException e) {

//            e.printStackTrace();

//        }

    }

}