Two threads trying to read a property of an object

Read Write problem

/*
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 * To change this template file, choose Tools | Templates
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 */
package javaapplication3;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author evaldo
 */
class Monitor {
    private static int number = 0;    
    
    public static int getNumber() {
        return number;
    }
    
    public static void increment() {
        number++;
    }
}

class Even implements Runnable {
    @Override
    public void run() {
        while (true) {
            
            System.out.println("Even" + " - " + Monitor.getNumber());

        }
    }
    
}

class Odd implements Runnable {
    @Override
    public void run() {
        while (true) {
            System.out.println("Odd" + " - " + Monitor.getNumber());
            
        }
    }
    
}
public class JavaApplication3 {
    
    
    public static void main(String[] args) {
        Even e = new Even();
        Odd o = new Odd();
        
        
        o.run();
        e.run();
    }
    
}

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package javaapplication3;

import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author evaldo
 */
class Monitor {
    public static int number = 0;    
}

public class JavaApplication3 {
    
    
    public static void main(String[] args) {
        Thread a = new Thread() {
            public void run() {
                while (true) {
                    if(Monitor.number % 2 == 0) {
                        System.out.println(this.getName() + " - " + Monitor.number);
                        Monitor.number++;
                    }
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException ex) {
                        Logger.getLogger(JavaApplication3.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
                
            }
        };
        a.setName("Thread A");
        
        Thread b = new Thread() {
            public void run() {
                while (true) {
                    if(Monitor.number % 2 == 1) {
                        System.out.println(this.getName() + " - " + Monitor.number);
                        Monitor.number++;
                    }
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException ex) {
                        Logger.getLogger(JavaApplication3.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
            }
        };
        b.setName("Thread B");
        
        a.start();
        b.start();
    }
    
}