shortest job first

/*THIS IS A SCHEDULING ALGORITHAM OF TYPE NON-PREEMPTIVE.SJF
MEANS SHORTEST JOB FIRST.THAT MEANS THE PROCESS HAVING SHORTEST SERVICE
TIME WILL BE PROCESSED NEXT.THIS PROGRAM WILL BE HELP FULL TO STUDY THE
PROCESS HANDLING IN THE CPU.*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

class fcfs extends JFrame implements ActionListener
{
JButton jb[] = new JButton[3];
JTextField jt1[],jt2[];
JLabel jl[],jl1,jl2,jl3;
JPanel jp,jp1;
Container con;
int k,p;
String str[] = {"SUBMIT","RESET","EXIT"};
String str1[] = {"Process"," AT","ST","WT","FT","TAT","NTAT"};


public fcfs()
{
super("fcfs scheduling algoritham");
con = getContentPane();

k= Integer.parseInt(JOptionPane.showInputDialog("Enter number of
process"));

jl1 = new JLabel("Process");
jl2 = new JLabel("Arival Time");
jl3 = new JLabel("Service Time");

jl = new JLabel[k];
jt1 = new JTextField[k];
jt2 = new JTextField[k];


for(int i=0;i {
jl[i] = new JLabel("process"+(i+1));
jt1[i] = new JTextField(10);
jt2[i] = new JTextField(10);
}

for(int i=0;i<3;i++)
{
jb[i] = new JButton(str[i]);
}

con.setLayout(new GridLayout(k+2,3));
con.add(jl1);
con.add(jl2);
con.add(jl3);

int l=0;

for(int i=0;i {
con.add(jl[l]);
con.add(jt1[l]);
con.add(jt2[l]);
l++;
}
l=0;
for(int i=0;i<3;i++)
{
con.add(jb[l]);
jb[l].addActionListener(this);
l++;
}
}//end of constructor

public void actionPerformed(ActionEvent ae)
{
int FT[] = new int[k];
int WT[] = new int[k];
int TAT[] = new int[k];
float NTAT[] = new float[k];
float sum=0;
float avg;
JPanel main = new JPanel();
main.setLayout(new BorderLayout());
jp = new JPanel();
jp1 = new JPanel();
jp.setLayout(new GridLayout(k+1,7));
jp1.setLayout(new FlowLayout());

if(ae.getSource() == jb[2])
{
System.exit(0);
}
else if(ae.getSource() == jb[0])
{
FT[0] = Integer.parseInt(jt1[0].getText()) +
Integer.parseInt(jt2[0].getText());

for(int i=0;i {
if(i==0)
{
WT[i] = 0;
}
else
{
if(FT[i-1] < Integer.parseInt(jt1[i].getText()))
{
FT[i] =
Integer.parseInt(jt1[i].getText())+Integer.parseInt(jt2[i].getText());
WT[i] = 0;
}
else
{
FT[i] = FT[i-1] + Integer.parseInt(jt2[i].getText());
WT[i] = FT[i-1] - Integer.parseInt(jt1[i].getText());
}

}
TAT[i] = WT[i]+Integer.parseInt(jt2[i].getText());
NTAT[i] = TAT[i]/(Integer.parseInt(jt2[i].getText()));
sum = sum+WT[i];


}//end for loop
for (int i=0;i<7;i++ )
{
jp.add(new JLabel(str1[i]));
}
for (int i=0;i {
jp.add(new JLabel("process"+(i+1)));
jp.add(new JLabel(" "+Integer.parseInt(jt1[i].getText())));
jp.add(new JLabel(""+Integer.parseInt(jt2[i].getText())));
jp.add(new JLabel(""+WT[i]));
jp.add(new JLabel(""+FT[i]));
jp.add(new JLabel(""+TAT[i]));
jp.add(new JLabel(""+NTAT[i]));


}
avg = sum/k;
String str2 = "Average Waiting Time is "+ avg;
jp1.add(new JLabel(str2));
main.add(jp,BorderLayout.NORTH);
main.add(jp1,BorderLayout.SOUTH);

JOptionPane.showMessageDialog(null,main,"output",JOptionPane.PLAIN_MESSAGE
);

}
else if(ae.getSource() == jb[1])
{
setVisible(false);
fcfs window = new fcfs();
window.setSize(400,300);
window.setVisible(true);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}
}//END ACTION PERFORMED

public static void main(String[] args)
{
fcfs window = new fcfs();
window.setSize(400,300);
window.setVisible(true);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}//end main
}//end class