如果您正在使用Jrockit虚拟机，那么这里有另一种获取虚拟机CPU使用情况的方法。运行时bean还可以提供每个处理器的CPU负载。我只在Red Hat Linux上使用它来观察Tomcat性能。您必须在catalina.sh中启用JMX remote才能使其工作。

JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://my.tomcat.host:8080/jmxrmi");
JMXConnector jmxc = JMXConnectorFactory.connect(url, null);     
MBeanServerConnection conn = jmxc.getMBeanServerConnection();       
ObjectName name = new ObjectName("oracle.jrockit.management:type=Runtime");
Double jvmCpuLoad =(Double)conn.getAttribute(name, "VMGeneratedCPULoad");

java.lang.management包确实比运行时提供了更多的信息——例如，它会将堆内存(ManagementFactory.getMemoryMXBean(). getheapmemoryusage())与非堆内存(ManagementFactory.getMemoryMXBean(). getnonheapmemoryusage())分开。

您还可以获得进程CPU使用情况(无需编写自己的JNI代码)，但是您需要将java.lang.management.OperatingSystemMXBean转换为com.sun.management.OperatingSystemMXBean。这适用于Windows和Linux，我还没有在其他地方测试过。

例如……更频繁地调用get getCpuUsage()方法以获得更准确的读数。

public class PerformanceMonitor { 
    private int  availableProcessors = getOperatingSystemMXBean().getAvailableProcessors();
    private long lastSystemTime      = 0;
    private long lastProcessCpuTime  = 0;

    public synchronized double getCpuUsage()
    {
        if ( lastSystemTime == 0 )
        {
            baselineCounters();
            return;
        }

        long systemTime     = System.nanoTime();
        long processCpuTime = 0;

        if ( getOperatingSystemMXBean() instanceof OperatingSystemMXBean )
        {
            processCpuTime = ( (OperatingSystemMXBean) getOperatingSystemMXBean() ).getProcessCpuTime();
        }

        double cpuUsage = (double) ( processCpuTime - lastProcessCpuTime ) / ( systemTime - lastSystemTime );

        lastSystemTime     = systemTime;
        lastProcessCpuTime = processCpuTime;

        return cpuUsage / availableProcessors;
    }

    private void baselineCounters()
    {
        lastSystemTime = System.nanoTime();

        if ( getOperatingSystemMXBean() instanceof OperatingSystemMXBean )
        {
            lastProcessCpuTime = ( (OperatingSystemMXBean) getOperatingSystemMXBean() ).getProcessCpuTime();
        }
    }
}

通过maven添加OSHI依赖:

<dependency>
    <groupId>com.github.dblock</groupId>
    <artifactId>oshi-core</artifactId>
    <version>2.2</version>
</dependency>

获得电池容量剩余百分比:

SystemInfo si = new SystemInfo();
HardwareAbstractionLayer hal = si.getHardware();
for (PowerSource pSource : hal.getPowerSources()) {
    System.out.println(String.format("%n %s @ %.1f%%", pSource.getName(), pSource.getRemainingCapacity() * 100d));
}

不是你想要的，但是我建议你从common -lang3中查看ArchUtils和SystemUtils。它们还包含一些相关的辅助工具，例如:

import static org.apache.commons.lang3.ArchUtils.*;
import static org.apache.commons.lang3.SystemUtils.*;

System.out.printf("OS architecture: %s\n", OS_ARCH); // OS architecture: amd64
System.out.printf("OS name: %s\n", OS_NAME);         // OS name: Linux
System.out.printf("OS version: %s\n", OS_VERSION);   // OS version: 5.18.16-200.fc36.x86_64

System.out.printf("Is Linux? - %b\n", IS_OS_LINUX);     // Is Linux? - true
System.out.printf("Is Mac? - %b\n", IS_OS_MAC);         // Is Mac? - false
System.out.printf("Is Windows? - %b\n", IS_OS_WINDOWS); // Is Windows? - false

System.out.printf("JVM name: %s\n", JAVA_VM_NAME);       // JVM name: Java HotSpot(TM) 64-Bit Server VM
System.out.printf("JVM vendor: %s\n", JAVA_VM_VENDOR);   // JVM vendor: Oracle Corporation
System.out.printf("JVM version: %s\n", JAVA_VM_VERSION); // JVM version: 11.0.12+8-LTS-237

System.out.printf("Username: %s\n", getUserName()); // Username: johndoe
System.out.printf("Hostname: %s\n", getHostName()); // Hostname: garage-pc

var processor = getProcessor();
System.out.printf("CPU arch: %s\n", processor.getArch())  // CPU arch: BIT_64
System.out.printf("CPU type: %s\n", processor.getType()); // CPU type: X86

有一个使用JNA(因此不需要安装本机库)的Java项目正在积极开发中。它目前支持Linux, OSX, Windows, Solaris和FreeBSD，并提供RAM, CPU，电池和文件系统信息。

https://github.com/oshi/oshi

一个简单的方法可以用来获得操作系统级别的信息，我在我的Mac上测试，效果很好:

 OperatingSystemMXBean osBean =
        (OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
    return osBean.getProcessCpuLoad();

您可以在这里找到操作系统的许多相关指标