Get OS-level system information

Question

I\'m currently building a Java app that could end up being run on many different platforms, but primarily variants of Solaris, Linux and Windows.

Has anyone been abl

Answer 1

One simple way which can be used to get the OS level information and I tested in my Mac which works well :

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

You can find many relevant metrics of the operating system here

Answer 2

If you are using Jrockit VM then here is an other way of getting VM CPU usage. Runtime bean can also give you CPU load per processor. I have used this only on Red Hat Linux to observer Tomcat performance. You have to enable JMX remote in catalina.sh for this to work.

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");

Answer 3

The java.lang.management package does give you a whole lot more info than Runtime - for example it will give you heap memory (ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()) separate from non-heap memory (ManagementFactory.getMemoryMXBean().getNonHeapMemoryUsage()).

You can also get process CPU usage (without writing your own JNI code), but you need to cast the java.lang.management.OperatingSystemMXBean to a com.sun.management.OperatingSystemMXBean. This works on Windows and Linux, I haven't tested it elsewhere.

For example ... call the get getCpuUsage() method more frequently to get more accurate readings.

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();
        }
    }
}

Answer 4

You can get some system-level information by using System.getenv(), passing the relevant environment variable name as a parameter. For example, on Windows:

System.getenv("PROCESSOR_IDENTIFIER")
System.getenv("PROCESSOR_ARCHITECTURE")
System.getenv("PROCESSOR_ARCHITEW6432")
System.getenv("NUMBER_OF_PROCESSORS")

For other operating systems the presence/absence and names of the relevant environment variables will differ.

Answer 5

It is still under development but you can already use jHardware

It is a simple library that scraps system data using Java. It works in both Linux and Windows.

ProcessorInfo info = HardwareInfo.getProcessorInfo();
//Get named info
System.out.println("Cache size: " + info.getCacheSize());        
System.out.println("Family: " + info.getFamily());
System.out.println("Speed (Mhz): " + info.getMhz());
//[...]

Answer 6

Hey you can do this with java/com integration. By accessing WMI features you can get all the information.