koding deret pakai JAVA

import javax.swing.*;
class deret{
public static void main(String[]Args){
int angka = Integer.parseInt(JOptionPane.showInputDialog("masukkan angka : "));
for(int k = 1;k<=angka;k++){
for(int m = angka;m>=k;m--){
System.out.print(" ");
}
for(int j = 1;j<=k;j++){
System.out.print("*"+" ");
}
System.out.print("\n");
}
for(int s = 1;s<=angka;s++){
for(int t = 0;t<=s;t++){
System.out.print(" ");
}
for(int j = angka-1;j>=s;j--){
System.out.print("*"+" ");
}
System.out.print("\n");
}
}
}