最近做一个Java性能统计的问题，需要统计当前进程占用CPU的情况，最开始使用Java MxBean来获取 OperatingSystemMXBean osMxBean = ManagementFactory.getOperatingSystemMXBean(); double cpu = osMxBean.getSystemLoadAverage(); 但是这个方法得到的操作系统统计的整个系统负载，不能较好的反应本进程的CPU占用情况，然后就是用一个新的方法，通过统计线程CPU占用时间来做统计，具体代码如下：
package com.service.article;
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.lang.management.ThreadMXBean;
public class CPUMonitorCalc {
private static CPUMonitorCalc instance = new CPUMonitorCalc();
private OperatingSystemMXBean osMxBean;
private ThreadMXBean threadBean;
private long preTime = System.nanoTime();
private long preUsedTime = 0;
private CPUMonitorCalc() {
osMxBean = ManagementFactory.getOperatingSystemMXBean();
threadBean = ManagementFactory.getThreadMXBean();
}
public static CPUMonitorCalc getInstance() {
return instance;
}
public double getProcessCpu() {
long totalTime = 0;
for (long id : threadBean.getAllThreadIds()) {
totalTime += threadBean.getThreadCpuTime(id);
}
long curtime = System.nanoTime();
long usedTime = totalTime - preUsedTime;
long totalPassedTime = curtime - preTime;
preTime = curtime;
preUsedTime = totalTime;
return (((double) usedTime) / totalPassedTime / osMxBean.getAvailableProcessors()) * 100;
}
}
测试方法：
package com.service.article;
public class ArticleApplication {
public static void main(String[] args) throws Exception {
for (int i = 0; i < 2; i++) {
new Thread(() -> {
while (true) {
long bac = 1000000;
bac = bac >> 1;
}
}).start();;
}
while (true) {
Thread.sleep(5000);
System.out.println(CPUMonitorCalc.getInstance().getProcessCpu());
}
}
}
测试结果跟操作系统统计出来的结果几乎一样
