Thread: getProcessCPUTime()

Hi.
What is the error at line 42?

import java.io.*;
import java.util.*;
import com.sun.management.OperatingSystemMXBean;
import java.lang.management.ManagementFactory;
import java.lang.System;
 
    public class sysinfoHooshi{
 
	public static void prt(String s){System.out.print(s);}
	public static void main(String args[]) throws Exception{
		int k = 10;//k recent pieces of info will be maintained
 
		OperatingSystemMXBean osBean =
		 (com.sun.management.OperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
		class Info{			
			public String name;
			public String version;
			public String arch;
			long CPUSpeed;
		};
		Info info =  new Info();
		Info[] queue = new Info[100];
 
		int pos = 1;
 
		Date d = new Date();
		long start = d.getTime();
 
		while(true){
			long time = d.getTime();
			if( (start-time)%3 == 0 )
			{
				queue[pos].name = System.getProperty("os.name");
				System.out.println( queue[pos].name);
				queue[pos].version = System.getProperty("os.version");
				queue[pos].arch = System.getProperty("os.arch");
				pos++;
			}
 
		}
 
		info.CPUSpeed = OperatingSystemMXBean.getProcessCPUTime();//javac ERROR!!
 
 
 
	} // end main
   }// end class date

My terminal screen reads: (I am on ubuntu 12.04 LTS):

~$ javac sysinfoHooshi.java
sysinfoHooshi.java:42: cannot find symbol
symbol : method getProcessCPUTime()
location: interface com.sun.management.OperatingSystemMXBean
info.CPUSpeed = OperatingSystemMXBean.getProcessCPUTime();
^
1 error

But I apparently have imported that. Isn't Java 'import' = C++ using?

One problem I see is the following:

Info[] queue = new Info[100];
...
info.CPUSpeed = ... ;

What do you think is going to happen here?

Originally Posted by KevinWorkman

I'm really not sure what you think that's supposed to do. Answer these questions:

What functions are in the OperatingSystemMXBean class?

What *static* functions are in the OperatingSystemMXBean class?

What function are you trying to access? Are you trying to access it statically?

I want to get CPU speed + Memory usage and maybe other administrating information

I just wanna use 'getProcessCpuTime()

Originally Posted by KevinWorkman

Okay, and what class does that belong to?

It says it is part of OperatingSystemMXBean interface, but I don't know how to use interfaces

--- Update ---

I managed to get itt compiled and run, by adding:

import com.sun.management.OperatingSystemMXBean;
.
.
.
OperatingSystemMXBean osBean = (com.sun.management.OperatingSystemMXBean)
ManagementFactory.getOperatingSystemMXBean();

info.CPUSpeed = osBean.getProcessCpuTime();

System.out.println(info.CPUSpeed);

But I don't know How exactoly to get the CPU frequency.

Please....What does the function do exactly?I cannot understand the document completely

Originally Posted by Norm

Please copy the text of the doc that you don't understand and post it here with your questions about it.

I don't understand what does it mean that the function

Returns the CPU time used by the process on which the Java virtual machine is running in nanoseconds.

and what's the use of it

Hi.
What's wrong with my invokation of getSystemCpuLoad?
Here is How my code looks like:

OperatingSystemMXBean osBean = (com.sun.management.OperatingSystemMXBean)
			ManagementFactory.getOperatingSystemMXBean();
 
double CPUUtil = ( osBean.getSystemCpuLoad() ) * 100;

and here is the output from javac:

$ javac sysinfoHooshi.java
sysinfoHooshi.java:43: cannot find symbol
symbol : method getSystemCpuLoad()
location: interface com.sun.management.OperatingSystemMXBean
queue[pos].CPUUtil = ( osBean.getSystemCpuLoad() ) * 100;
^
1 error

The code that you show and the error you posted do not belong together.
Read the error message, it tells you what the problem is:

queue[pos].CPUUtil = ( osBean.getSystemCpuLoad() ) * 100;

Is wrong because the variable "queue" is not a known symbol.

Originally Posted by Cornix

The code that you show and the error you posted do not belong together.
Read the error message, it tells you what the problem is:

Is wrong because the variable "queue" is not a known symbol.

no.'queue' is defined:

class Info{
public String name;
public String version;
public String arch;
public double ramUtil;
public double CPUUtil;
};

Info[] queue = new Info[queueSize];

int pos = 0;

for(int i=0;i<queueSize;++i)
queue[i] = new Info();

the problem is in the RHS of the assignment

Please post your code in code tags.

Yes Norm I have. What is JNI and how to use it?

JNI stands for Java Native Interface. Its an API that allows you to use native libraries.