Clase Java para monitorizar la carga de proceso Java

import java.lang.management.ManagementFactory;

import java.lang.management.OperatingSystemMXBean;

import java.util.ArrayList;

import java.util.Calendar;

import java.util.GregorianCalendar;

import java.util.List;

public class PerformanceMonitor {

private int availableProcessors = ManagementFactory.getOperatingSystemMXBean().getAvailableProcessors();

private long lastSystemTime = 0;

private long lastProcessCpuTime = 0;

public PerformanceMonitor() {

// Inicializar la estadistica

getCpuUsage();

}

public synchronized String getStats() {

java.lang.management.OperatingSystemMXBean os = ManagementFactory.getOperatingSystemMXBean();

com.sun.management.OperatingSystemMXBean osDetail = null;

if ( os instanceof com.sun.management.OperatingSystemMXBean ) {

osDetail = (com.sun.management.OperatingSystemMXBean)os;

}

StringBuffer stats = new StringBuffer();

stats.append( «operating system architecture: » + osDetail.getArch() + «\n» );

stats.append( «processors available to the Java virtual machine: » + osDetail.getAvailableProcessors() + «\n» );

stats.append( «virtual memory guaranteed to the running process in Mb: » + osDetail.getCommittedVirtualMemorySize() / (1024 * 1024) + «\n» );

stats.append( «amount of free physical memory in Mb: » + osDetail.getFreePhysicalMemorySize() / (1024 * 1024) + «\n» );

stats.append( «amount of free swap space in bytes: » + osDetail.getFreeSwapSpaceSize()/ (1024 * 1024) + «\n» );

stats.append( «operating system name: » + osDetail.getName() + «\n» );

stats.append( «jvm process CPU time in seconds: » + osDetail.getProcessCpuTime() / (1000 * 1000) + «\n» );

stats.append( «system load average for the last minute: » + osDetail.getSystemLoadAverage() + «\n» );

stats.append( «total amount of physical memory in Mb: » + osDetail.getTotalPhysicalMemorySize()/ (1024 * 1024) + «\n» );

stats.append( «total amount of swap space in Mb: » + osDetail.getTotalSwapSpaceSize()/ (1024 * 1024) + «\n» );

stats.append( «operating system version: » + osDetail.getVersion() + «\n» );

stats.append( «Total Heap Memory bytes: » + Runtime.getRuntime().totalMemory() + «\n» );

stats.append( «Free Heap Memory bytes: » + Runtime.getRuntime().freeMemory() + «\n» );

return stats.toString();

}

public synchronized long getHeapSpace() {

Runtime runtime = Runtime.getRuntime();

return runtime.maxMemory();

}

public synchronized long getFreeHeap() {

Runtime runtime = Runtime.getRuntime();

return runtime.freeMemory() + runtime.maxMemory() – runtime.totalMemory();

}

public synchronized double getCpuUsage() {

if ( lastSystemTime == 0 ) {

baselineCounters();

return -1.0;

}

long systemTime = System.nanoTime();

long processCpuTime = 0;

if ( ManagementFactory.getOperatingSystemMXBean() instanceof OperatingSystemMXBean ) {

processCpuTime = ( (com.sun.management.OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean() ).getProcessCpuTime();

}

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

lastSystemTime = systemTime;

lastProcessCpuTime = processCpuTime;

return cpuUsage / availableProcessors;

}

private void baselineCounters() {

lastSystemTime = System.nanoTime();

if ( ManagementFactory.getOperatingSystemMXBean() instanceof OperatingSystemMXBean ) {

lastProcessCpuTime = ( (com.sun.management.OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean() ).getProcessCpuTime();

}

}

public static void main( String[] args ) throws Exception {

PerformanceMonitor performanceMonitor = new PerformanceMonitor();

List<Calendar> list = new ArrayList<Calendar>();

for ( int i = 0; i < 1000000000; i++ ) {

// Petar la lista con 1000 calendars

for ( int k = 0; k < 10000; k++ ){ list.add( new GregorianCalendar() ); }

// Petar la CPU con ciclos vacios

for ( int j = 0; j< 1000000000; j++ ) {}

// Mem en Mb

System.out.println( «CPU: » + performanceMonitor.getCpuUsage() + «\t\tMem: » + performanceMonitor.getFreeHeap() / (1024d*1024d) + » (» + performanceMonitor.getHeapSpace() / (1024d*1024d) + «)» );

}

}

}

processors available to the Java virtual machine: 2

virtual memory guaranteed to the running process in Mb: 26

amount of free physical memory in Mb: 1398

amount of free swap space in bytes: 2414

operating system name: Windows XP

jvm process CPU time in seconds: 31

system load average for the last minute: -1.0

total amount of physical memory in Mb: 2047

total amount of swap space in Mb: 4095

operating system version: 5.1

CPU: 0.53092372493373 Mem: 59.24299621582031 (63.5625)

CPU: 0.49657241013084563 Mem: 54.95256805419922 (63.5625)

CPU: 0.4942800629113504 Mem: 50.687034606933594 (63.5625)

CPU: 0.5014447636314036 Mem: 46.33628845214844 (63.5625)

CPU: 0.49340744417460447 Mem: 42.19970703125 (63.5625)

CPU: 0.47895371827853395 Mem: 38.14019775390625 (63.5625)

CPU: 0.489600379360572 Mem: 34.019569396972656 (63.5625)

CPU: 0.5035100827089479 Mem: 29.867881774902344 (63.5625)

CPU: 0.4956995526839775 Mem: 25.292449951171875 (63.5625)

CPU: 0.5094588912754633 Mem: 21.131568908691406 (63.5625)

CPU: 0.4906238625778933 Mem: 17.017196655273438 (63.5625)

CPU: 0.5065215722196845 Mem: 12.91436767578125 (63.5625)

CPU: 0.4985452957553055 Mem: 8.817756652832031 (63.5625)

CPU: 0.4914929960487762 Mem: 3.883514404296875 (63.5625)

CPU: 0.4986814075082175 Mem: 0.4375 (63.5625)

Exception in thread «main» java.lang.OutOfMemoryError: Java heap space

at java.util.Calendar.<init>(Unknown Source)

at java.util.GregorianCalendar.<init>(Unknown Source)

at java.util.GregorianCalendar.<init>(Unknown Source)

at test.PerformanceMonitor.main(PerformanceMonitor.java:92)