How to get CPU usage in percentage in java?
The closest I came to was this code I tried to adapt, but it shows different results compared to the Windows task manager
follow below
package teste;
import java.io.File;
import java.lang.management.ManagementFactory;
// import java.lang.management.Operating
SystemMXBean;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.management.RuntimeMXBean;
import java.io.*;
import java.net.*;
import java.util.*;
import java.io.LineNumberReader;
import java.lang.management.ManagementFactory;
import com.sun.management.OperatingSystemMXBean;
import java.lang.management.ManagementFactory;
import java.util.Random;
public class Teste {
public static void printUsage(Runtime runtime)
{
long total, free, used;
int mb = 1024*1024;
total = runtime.totalMemory();
free = runtime.freeMemory();
used = total - free;
System.out.println("\nTotal Memory: " + total / mb + "MB");
System.out.println(" Memory Used: " + used / mb + "MB");
System.out.println(" Memory Free: " + free / mb + "MB");
System.out.println("Percent Used: " + ((double)used/(double)total)*100 + "%");
System.out.println("Percent Free: " + ((double)free/(double)total)*100 + "%");
}
public static void log(Object message)
{
System.out.println(message);
}
public static int calcCPU(long cpuStartTime, long elapsedStartTime, int cpuCount)
{
long end = System.nanoTime();
long totalAvailCPUTime = cpuCount * (end-elapsedStartTime);
long totalUsedCPUTime = ManagementFactory.getThreadMXBean().getCurrentThreadCpuTime()-cpuStartTime;
//log("Total CPU Time:" + totalUsedCPUTime + " ns.");
//log("Total Avail CPU Time:" + totalAvailCPUTime + " ns.");
float per = ((float)totalUsedCPUTime*100)/(float)totalAvailCPUTime;
log( per);
return (int)per;
}
static boolean isPrime(int n)
{
// 2 is the smallest prime
if (n <= 2)
{
return n == 2;
}
// even numbers other than 2 are not prime
if (n % 2 == 0)
{
return false;
}
// check odd divisors from 3
// to the square root of n
for (int i = 3, end = (int)Math.sqrt(n); i <= end; i += 2)
{
if (n % i == 0)
{
return false;
}
}
return true;
}
public static void main(String [] args)
{
int mb = 1024*1024;
int gb = 1024*1024*1024;
/* PHYSICAL MEMORY USAGE */
System.out.println("\n**** Sizes in Mega Bytes ****\n");
com.sun.management.OperatingSystemMXBean operatingSystemMXBean = (com.sun.management.OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
//RuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();
//operatingSystemMXBean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
com.sun.management.OperatingSystemMXBean os = (com.sun.management.OperatingSystemMXBean)
java.lang.management.ManagementFactory.getOperatingSystemMXBean();
long physicalMemorySize = os.getTotalPhysicalMemorySize();
System.out.println("PHYSICAL MEMORY DETAILS \n");
System.out.println("total physical memory : " + physicalMemorySize / mb + "MB ");
long physicalfreeMemorySize = os.getFreePhysicalMemorySize();
System.out.println("total free physical memory : " + physicalfreeMemorySize / mb + "MB");
/* DISC SPACE DETAILS */
File diskPartition = new File("C:");
File diskPartition1 = new File("D:");
File diskPartition2 = new File("E:");
long totalCapacity = diskPartition.getTotalSpace() / gb;
long totalCapacity1 = diskPartition1.getTotalSpace() / gb;
double freePartitionSpace = diskPartition.getFreeSpace() / gb;
double freePartitionSpace1 = diskPartition1.getFreeSpace() / gb;
double freePartitionSpace2 = diskPartition2.getFreeSpace() / gb;
double usablePatitionSpace = diskPartition.getUsableSpace() / gb;
System.out.println("\n**** Sizes in Giga Bytes ****\n");
System.out.println("DISC SPACE DETAILS \n");
//System.out.println("Total C partition size : " + totalCapacity + "GB");
//System.out.println("Usable Space : " + usablePatitionSpace + "GB");
System.out.println("Free Space in drive C: : " + freePartitionSpace + "GB");
System.out.println("Free Space in drive D: : " + freePartitionSpace1 + "GB");
System.out.println("Free Space in drive E: " + freePartitionSpace2 + "GB");
if(freePartitionSpace <= totalCapacity%10 || freePartitionSpace1 <= totalCapacity1%10)
{
System.out.println(" !!!alert!!!!");
}
else
System.out.println("no alert");
Runtime runtime;
byte[] bytes;
System.out.println("\n \n**MEMORY DETAILS ** \n");
// Print initial memory usage.
runtime = Runtime.getRuntime();
printUsage(runtime);
// Allocate a 1 Megabyte and print memory usage
bytes = new byte[1024*1024];
printUsage(runtime);
bytes = null;
// Invoke garbage collector to reclaim the allocated memory.
runtime.gc();
// Wait 5 seconds to give garbage collector a chance to run
try {
Thread.sleep(5000);
} catch(InterruptedException e) {
e.printStackTrace();
return;
}
// Total memory will probably be the same as the second printUsage call,
// but the free memory should be about 1 Megabyte larger if garbage
// collection kicked in.
printUsage(runtime);
for(int i = 0; i < 30; i++)
{
long start = System.nanoTime();
// log(start);
//number of available processors;
int cpuCount = ManagementFactory.getOperatingSystemMXBean().getAvailableProcessors();
Random random = new Random(start);
int seed = Math.abs(random.nextInt());
log("\n \n CPU USAGE DETAILS \n\n");
log("Starting Test with " + cpuCount + " CPUs and random number:" + seed);
int primes = 10000;
//
long startCPUTime = ManagementFactory.getThreadMXBean().getCurrentThreadCpuTime();
start = System.nanoTime();
while(primes != 0)
{
if(isPrime(seed))
{
primes--;
}
seed++;
}
float cpuPercent = calcCPU(startCPUTime, start, cpuCount);
log("CPU USAGE : " + cpuPercent + " % ");
try
{
Thread.sleep(1000);
}
catch (InterruptedException e) {}
}
try
{
Thread.sleep(500);
}
catch (Exception ignored) { }
}
}