我只是個路過的宅宅而已~...阿凱凱 ^_^

public class test6_7{
    public static void main(String[] args){
        for(int i=1;i<=4;i++){
            for(int j=1;j<=4-i;j++)
                System.out.print(" ");
            for(int j=1;j<2*i;j++)
                System.out.print("*");
            System.out.println();
            }
        for(int i=3;i>=1;i--){
         for(int j=1;j<=4-i;j++)
                System.out.print(" ");
            for(int j=1;j<2*i;j++)
                System.out.print("*");
            System.out.println();
       
        }
    }
}