Thread: cannot find symbol:getSystemCpuLoad()

Originally Posted by hooshdar3

It is just that My professor wanted me to write a java code, and he doesn't tell us what to do

Originally Posted by hooshdar3

I have studied some examples, but believe me or not, I have no teacher. Never had any teacher.

Well I'm confused. I assume you mean to say that you haven't had a formal education in Java, but then I would argue that a formal education isn't necessary as long as you have the drive to learn the language yourself. Greg's point, as far as I can tell, is that without understanding the fundamentals of Java and programming in general, you're going to run into some very basic misunderstandings and issues.

As for the last question that you asked, what are the checkboxes supposed to do when they are ticked? What is the desired output of the program? It's difficult to pin down how a program is misbehaving without knowing how it is meant to behave in the first place.

Originally Posted by DuncanS

Well I'm confused. I assume you mean to say that you haven't had a formal education in Java, but then I would argue that a formal education isn't necessary as long as you have the drive to learn the language yourself. Greg's point, as far as I can tell, is that without understanding the fundamentals of Java and programming in general, you're going to run into some very basic misunderstandings and issues.

As for the last question that you asked, what are the checkboxes supposed to do when they are ticked? What is the desired output of the program? It's difficult to pin down how a program is misbehaving without knowing how it is meant to behave in the first place.

The check boxes will read "OS version", "CPU architecture", etc , according to which some boolean variables are set, which help to decide which fields of a stored object in a queue will be retrieved.
But the error is exactly on the getSystemCpuLoad() line: I commented it out nd the compiler error disp\appeared

Okay, let's get back on topic . . .

Post your latest code that demonstrates the problem - two JDialogs with one button each, some check boxes if needed, describe the problem or your confusion, and ask the questions needed to resolve any problems and move on. Focus on understanding and fixing one thing at a time.

Originally Posted by GregBrannon

Okay, let's get back on topic . . .

Post your latest code that demonstrates the problem - two JDialogs with one button each, some check boxes if needed, describe the problem or your confusion, and ask the questions needed to resolve any problems and move on. Focus on understanding and fixing one thing at a time.

My latest, shortened code is:

import java.io.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
import com.sun.management.OperatingSystemMXBean;
import java.lang.management.ManagementFactory;
import java.lang.System;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
 
    public class SysinfoHooshi implements ActionListener{
		int k;
 
		class Info{			
			public String name;
			public String version;
			public String arch;
			public double ramUtil;
			public double CPUUtil;
		};
 
    JTextField  tf = new JTextField("");
    JTextField  tf2 = new JTextField("");
    JDialog dialog = new  JDialog();	
    JButton button = new JButton("OK");
 
    /****************Query dialog variables*******************/
    JDialog queryDialog = new  JDialog();	
    JButton queryButton = new JButton("OK");
    JCheckBox chkCPUUtil = new JCheckBox("CPU utilization");
    JCheckBox chkRAMUtil = new JCheckBox("RAM utilization");
    JCheckBox chkVersion = new JCheckBox("Version of the OS");
    JCheckBox chkArch = new JCheckBox("Processor architecture");
    JCheckBox chkName = new JCheckBox("Operating system name");
    boolean nameChecked, versionChecked, archChecked, CPUChecked, RAMChecked;
    /*********************************************************/
 
	public  void simulate()throws Exception{
 
		this.showDialog();
		showQueryDialog();
 
	}//end simulate()
 
	public void showDialog()
	{
		dialog.setModal(true);
		dialog.setSize(400, 150);
 
		dialog.setTitle("Input dialog");
 
		Container pane = dialog.getContentPane();
		pane.setLayout(null);
 
 
		JLabel l1 = new JLabel("simtime(min)");
		pane.add(l1);
		l1.setBounds(10, 10, 100, 10);
 
 
		pane.add( tf);
		tf.setBounds(110,10, 40, 15);
 
		JLabel l2 = new JLabel("interval(sec)") ;
		pane.add(l2);
		l2.setBounds(10, 50, 100, 10);
 
 
		pane.add( tf2);
		tf2.setBounds(110,50, 40, 15);
 
 
		pane.add(button);
		button.addActionListener(this);
		button.setBounds(100,100,80,30);
		dialog.setVisible(true);
	}
 
	 public void actionPerformed(ActionEvent e) {
		 if(e.getSource() == button)
		    dialog.setVisible(false);
		 if(e.getSource() == queryButton)
		    queryDialog.setVisible(false);
	}
 
	public void showQueryDialog()
	{
		queryDialog.setModal(true);
		queryDialog.setSize(400, 150);
 
		queryDialog.setTitle("Query dialog");
 
		JPanel queryPane = new  JPanel();
		queryPane.setLayout(new FlowLayout());
		queryPane.add(chkName);
		queryPane.add(chkVersion);
		queryPane.add(chkArch);	
		queryPane.add(queryButton);
		queryDialog.add(queryPane);	
		queryDialog.setVisible(true);
 
 
				chkName.addItemListener (new ItemListener() {
			public void itemStateChanged( ItemEvent e)
			{nameChecked=e.getStateChange()==1 ? true : false;}
		});
 
		chkVersion.addItemListener (new ItemListener() {
			public void itemStateChanged( ItemEvent e)
			{ versionChecked=e.getStateChange()==ItemEvent.SELECTED ? true : false;}
		});
 
		chkArch.addItemListener (new ItemListener() {
			public void itemStateChanged( ItemEvent e)
			{ archChecked=e.getStateChange()==1 ? true : false;}
		});
 
		chkCPUUtil.addItemListener (new ItemListener() {
			public void itemStateChanged( ItemEvent e)
			{ CPUChecked=e.getStateChange()== 1 ? true :false;}
		});
 
		chkRAMUtil.addItemListener (new ItemListener() {
			public void itemStateChanged( ItemEvent e)
			{ RAMChecked = e.getStateChange()==1 ? true :false;}
		});
 
		/*queryButton.addActionListener(this);
	}
 
 
	public static void main(String args[]) throws Exception{	
	SysinfoHooshi o = new SysinfoHooshi();
	o.simulate();
 
 
	} // end main
   }// end class

Both the buttons are supposed to hide their respective parent dialogues, but the second one doesn't.

Because the line where you add your action listener to the button is commented out.

/*queryButton.addActionListener(this);

You should really learn how to debug your code. Add System.out.println(...); statements to your methods to find out what is going on. This will help you to find errors in your code.

By the way, you should also read up on OOP design and start using separate classes for your different dialogs.

Originally Posted by hooshdar3

Why should I use one class per Dialog?

To make your code easier to read. Putting all of your code into one huge class is very bad practice.

Originally Posted by hooshdar3

What would be System.out.println() good for? I am seeing that the first button works when clicked, while the second doesn't (they should both close the dialog of which they are part

It would help you understand why your code does not work by showing you which parts work, and which parts dont.
You could add code to see whether the button is pressed but the condition is wrong. Or if an action listener was added in the first place.

Why should I use one class per Dialog?
What would be System.out.println() good for? I am seeing that the first button works when clicked, while the second doesn't (they should both close the dialog of which they are part

The first question was answered in the suggestion. Don't be difficult.

There are many ways to use println() to troubleshoot code. The most common are to track or trace the execution of code and to check variable values. If you see no value in its use, don't use it. Yes, you can see your code isn't working by observing the results, but you have no idea why. That's why you're here, and that's what others are trying to help you with.

Though I don't really know what "Grid Computing" is or what it has to do with programming, its concept seems consistent with OOP. That's another reason to use multiple classes rather than writing all of your code in one.

If you prefer to challenge the advice given by others rather than attempt to learn from it, this thread will be closed and you will be restricted from posting for a period of time.

Originally Posted by GregBrannon

The first question was answered in the suggestion. Don't be difficult.

There are many ways to use println() to troubleshoot code. The most common are to track or trace the execution of code and to check variable values. If you see no value in its use, don't use it. Yes, you can see your code isn't working by observing the results, but you have no idea why. That's why you're here, and that's what others are trying to help you with.

Though I don't really know what "Grid Computing" is or what it has to do with programming, its concept seems consistent with OOP. That's another reason to use multiple classes rather than writing all of your code in one.

If you prefer to challenge the advice given by others rather than attempt to learn from it, this thread will be closed and you will be restricted from posting for a period of time.

Grid computing has nothing to do with OOP.Its a form of distributed computing.

--- Update ---

Originally Posted by Cornix

It would help you understand why your code does not work by showing you which parts work, and which parts dont.
You could add code to see whether the button is pressed but the condition is wrong. Or if an action listener was added in the first place.

There is just one actionPerformed() method, so the problem is fairly pin-pointed

Originally Posted by Ada Lovelace

In that case - why is he not splitting the classes into Grid Computing and Java Programming
principles? Seems rather foolish that he is expecting a student to know the ins and outs of Java
whist learning a totally alien concept.

Wishes Ada xx

Java programming is a part of their undergraduate program, while we are graduate students.

Thread closed. Not making progress and OP is challenging rather than cooperating.