java使用java.lang.management监视和管理 Java 虚拟机

软件包 java.lang.management

提供管理接口，用于监视和管理 Java 虚拟机以及 Java 虚拟机在其上运行的操作系统。

 

接口摘要

 

ClassLoadingMXBean	用于 Java 虚拟机的类加载系统的管理接口。
CompilationMXBean	用于 Java 虚拟机的编译系统的管理接口。
GarbageCollectorMXBean	用于 Java 虚拟机的垃圾回收的管理接口。
MemoryManagerMXBean	内存管理器的管理接口。
MemoryMXBean	Java 虚拟机的内存系统的管理接口。
MemoryPoolMXBean	内存池的管理接口。
OperatingSystemMXBean	用于操作系统的管理接口，Java 虚拟机在此操作系统上运行。
RuntimeMXBean	Java 虚拟机的运行时系统的管理接口。
ThreadMXBean	Java 虚拟机线程系统的管理接口。

 

 

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();
//        }

    }

}