Shortest Job First Preemptive algorithm

/*
 * Scheduler.java
 *
 * Created on November 19, 2006, 7:46 PM
 
 */

package sjfscheduler;

/**
 *
 * @author samu
 */
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Scanner;
public class Scheduler {
	int numberOfProcesses;
	 
	private ArrayList processes = new ArrayList();
        private ArrayList inQueue = new ArrayList();
        private ArrayList Not_In_Queue_Yet = new ArrayList();
        private Proccess_Comperator  BusrtCom= new Proccess_Comperator();
        private Proccess_Comperator_Arr  BusrtCom_Arr= new Proccess_Comperator_Arr();
 
	 
        public void addProcess_Prim(myProcess p)
        {
            if(p.getArrivalTime()==0)
		inQueue.add(p);
            else
                Not_In_Queue_Yet.add(p);
		numberOfProcesses++;
	}
          public void schedule_SJF_Premitive()
     {
              int Time=0;
              int startProcessing=0;
             Collections.sort( inQueue,BusrtCom);
            Collections.sort( Not_In_Queue_Yet,BusrtCom_Arr); 
            myProcess processNow=null;
            myProcess processnew=null;
          while(true)
          {
             Time+=1;
             
             if(inQueue.size()!=0)
             {
           processNow=(myProcess)inQueue.get(0);
             
             if(processNow.getBurstTime()==1)
             {
                    System.out.println(processNow.getName()+" executed from: "+startProcessing+"--> "+Time  );
                          startProcessing=Time;
             inQueue.remove(0);
             }
             else
                processNow.decBurstTime();
             }
          if(Not_In_Queue_Yet.size()!=0)
          {
                  processnew=(myProcess)Not_In_Queue_Yet.get(0);
                  if(processnew.getArrivalTime()==Time)
                  {
                      if(processNow.getBurstTime()>processnew.getBurstTime())
                      {
                          System.out.println(processNow.getName()+" executed from: "+startProcessing+"--> "+Time );
                          startProcessing=Time;
                      }
                      inQueue.add(processnew.clone());
                      Not_In_Queue_Yet.remove(0);
                      Collections.sort( inQueue,BusrtCom);
                  }
          }
              if(Not_In_Queue_Yet.size()==0&&inQueue.size()==0)break;
             
          }
     }
public static void main(String[] args){
	//Create processes
        Scanner inKeyboard=new Scanner(System.in);
        int arrivalTime;
	int burstTime;
	String name;	  
        int numberOf_process;
        System.out.println("Plz enter the number of Process : ");
        numberOf_process=inKeyboard.nextInt();
        
        Scheduler scheduler = new Scheduler();	
        for(int i=1;i<=numberOf_process;i++)
        {
            System.out.println("Plz enter the arrival time of P"+i);
            arrivalTime=inKeyboard.nextInt();
            System.out.println("Plz enter the burstTime time of P"+i);
            burstTime=inKeyboard.nextInt();
           scheduler.addProcess_Prim(new myProcess(arrivalTime,burstTime,"P"+i));             
        }
     
	scheduler.schedule_SJF_Premitive();
	}
}
//The class of the process
class myProcess{
	private int arrivalTime;
	private int burstTime;
	private String name;	
	public myProcess(int arriveTime, int burstTime , String name) {
		this.arrivalTime = arriveTime;
		this.burstTime = burstTime;
		this.name = name;
	}
	//Get the arrive time value
	public int getArrivalTime() {
		return arrivalTime;
	}
	//Set the arrive time value
	public void setArrivalTime(int arrivalTime) {
		this.arrivalTime = arrivalTime;
	}
	//Get the burst time value
	public int getBurstTime() {
		return burstTime;
	}
	//Set the burst time value
	public void setBurstTime(int burstTime) {
		this.burstTime = burstTime;
	}
        public void decBurstTime() {
		 burstTime-=1;
	}
	//Get the process name
	public String getName() {
		return name;
	}
	//Set the process name
	public void setName(String name) {
		this.name = name;
	}
        public myProcess clone()
        {
            return new myProcess(arrivalTime,burstTime,name);
        }
}
  class Proccess_Comperator implements Comparator {
    
    /** Creates a new instance of Proccess_Comperator */
    public Proccess_Comperator() {
    }

    public int compare(Object o1, Object o2) 
    {
        int deff= ((myProcess)o1).getBurstTime()-((myProcess)o2).getBurstTime();
        
        if(deff<0)return -1;
        if(deff>0)return 1;
        return 0;
    }
    
}
  class Proccess_Comperator_Arr implements Comparator {
    
    /** Creates a new instance of Proccess_Comperator */
    public Proccess_Comperator_Arr() {
    }

    public int compare(Object o1, Object o2) 
    {
        int deff= ((myProcess)o1).getArrivalTime()-((myProcess)o2).getArrivalTime();
        
        if(deff<0)return -1;
        if(deff>0)return 1;
        return 0;
    }
    
}