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    <p>The <a href="http://java.sun.com/javase/6/docs/api/java/lang/management/package-summary.html" rel="noreferrer">java.lang.management</a> package does give you a whole lot more info than Runtime - for example it will give you heap memory (<code>ManagementFactory.getMemoryMXBean().getHeapMemoryUsage()</code>) separate from non-heap memory (<code>ManagementFactory.getMemoryMXBean().getNonHeapMemoryUsage()</code>).</p> <p>You can also get process CPU usage (without writing your own JNI code), but you need to cast the <code>java.lang.management.OperatingSystemMXBean</code> to a <code>com.sun.management.OperatingSystemMXBean</code>. This works on Windows and Linux, I haven't tested it elsewhere.</p> <p>For example ... call the get getCpuUsage() method more frequently to get more accurate readings.</p> <pre><code>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(); } } } </code></pre>
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    1. POget OS-level system information
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    1. USPatrick Wilkes
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    1. COThe code doesn't compile...
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      1. USfutureelite7
    2. COTo get it to compile, replace the cast `OperatingSystemMXBean` to `com.sun.management.OperatingSystemMXBean` and preface all instances of `getOperatingSystemMXBean()` with `ManagementFactory.`. You need to import all the classes appropriately.
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      1. UStmarthal
    3. COi'm getting cpu usage as 0 for everything. i changed the cpu usage formula to cpuUsage = processCpuTime / systemTime. i'm getting a value for cpu usage which i dont understand.
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      1. USRaj
 

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