JMX是什么？
JMX全称是Java Management Extensions。 Java 管理扩展。 它提供了对Java应用程序和JVM的监控和管理功能。
采集应用进程CPU使用率
static SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");public void monitorCPU() {try {// 操作系统 MXBeanOperatingSystemMXBean mxBean = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();// CPU核心数int processors = mxBean.getAvailableProcessors();// 运行时 MXBeanRuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();// 基于当前时间, 采集应用运行时长, 单位毫秒, 转换成纳秒,long prevUpTime = runtimeMXBean.getUptime() * 1000000;// 基于当前时间, 采集应用进程CPU运行时长, 单位毫秒long prevProcessCpuTime = mxBean.getProcessCpuTime() / processors;while (true) {// 每隔一秒采集一次TimeUnit.SECONDS.sleep(1);// 基于当前时间, 采集应用运行时长long processCpuTime = mxBean.getProcessCpuTime() / processors;// 基于当前时间, 采集应用进程CPU运行时长long upTime = runtimeMXBean.getUptime() * 1000000;String date = format.format(new Date());// 当前运行时长减去上一次的运行时长, 得到采样间隔long upTimeDiff = upTime - prevUpTime;// 当前应用进程运行时长减去上一次的运行时长, 得到采样间隔long processTimeDiff = processCpuTime - prevProcessCpuTime;/*** 计算应用进程CPU使用率,* 计算方式: CPU运行时间 / 总运行时间* 例如: upTimeDiff = 1秒, processTimeDiff = 0.2秒, 则应用进程CPU使用率为 20%** 也就是: 应用进程CPU使用时长, 在一段时间内的使用占比*/float processCPUUsage = Math.min((float) (processTimeDiff * 100) / (float) upTimeDiff, 100);// 将当前采样时间设置为上一次prevUpTime = upTime;prevProcessCpuTime = processCpuTime;System.out.println(date + " -进程CPU- " + String.format("%.2f", processCPUUsage) + "%");}} catch (Exception e) {e.printStackTrace();}}
效果图
第二种方式，需要jdk1.8才支持，而且数据不咋的准确。
OperatingSystemMXBean mxBean = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();System.out.println(" -进程CPU- " + String.format("%.2f", mxBean.getProcessCpuLoad() * 100) + "%");System.out.println(" -系统CPU- " + String.format("%.2f", mxBean.getSystemCpuLoad() * 100) + "%\n");
采集应用进程内存的使用
static NumberFormat fmtI = new DecimalFormat("###,###", new DecimalFormatSymbols(Locale.ENGLISH));public void monitorMemory() {List<MemoryPoolMXBean> memoryBeans = ManagementFactory.getMemoryPoolMXBeans();while (true) {for (MemoryPoolMXBean mxBean : memoryBeans) {StringBuilder sb = new StringBuilder();MemoryUsage usage = mxBean.getUsage();sb.append("内存模型: [").append(mxBean.getType().name()).append("], 内存空间名称: [").append(mxBean.getName()).append("], 初始化[").append(bytesToMB(usage.getInit())).append("], 已使用[").append(bytesToMB(usage.getUsed())).append("], 可使用[").append(bytesToMB(usage.getCommitted())).append("], 最大[").append(bytesToMB(usage.getMax())).append("]");System.out.println(sb);}System.out.println("------------------------------------------------------------------------------------------------------");try {TimeUnit.SECONDS.sleep(1);} catch (Exception e) {}}}
效果图
监控应用进程GC
public void monitorGC() {/*** 以JDK 1.8默认的GC回收器为例: Parallel Scavenge GC* gcMXBeans[0] PS Scavenge监控新生代垃圾回收* gcMXBeans[1] PS MarkSweep 监控老年代/元空间/堆外内存急其他*/List<GarbageCollectorMXBean> gcMXBeans = ManagementFactory.getGarbageCollectorMXBeans();GCNotificationListener listener = new GCNotificationListener();gcMXBeans.forEach(gcmx -> {NotificationEmitter emitter = (NotificationEmitter) gcmx;emitter.addNotificationListener(listener, null, null);});}private class GCNotificationListener implements NotificationListener {@Overridepublic void handleNotification(Notification notification, Object handback) {CompositeData cd = (CompositeData) notification.getUserData();GarbageCollectionNotificationInfo info = GarbageCollectionNotificationInfo.from(cd);GcInfo gcInfo = info.getGcInfo();Map<String, MemoryUsage> memoryUsageBeforeGc = gcInfo.getMemoryUsageBeforeGc();Map<String, MemoryUsage> memoryUsageAfterGc = gcInfo.getMemoryUsageAfterGc();System.out.println("GC前 - 内存情况 " + memoryUsageBeforeGc);System.out.println("GC后 - 内存情况 " + memoryUsageAfterGc);StringBuilder sb = new StringBuilder();sb.append("第[").append(gcInfo.getId()).append("]次").append("GC, 耗时: [").append(gcInfo.getDuration()).append("]毫秒, GC名称: [").append(info.getGcName()).append("], GC原因: [").append(info.getGcCause()).append("]");System.out.println(sb.toString());System.out.println("------------------------------------------------------------------------------------------------------");}}
效果图
