这是一道简单的打印图形题

public class Test1 {

  public static void main(String[] args) {
    for (int i = 1; i <= 4; i++) {//通过循环打印上半区
      for (int k = 1; k <= 4-i; k++) {//通过循环打印空格
        System.out.print(" ");
      }
      for (int j = 1; j <= 2*i-1; j++) {//通过循环打印*
        System.out.print("*");
      }      
      System.out.println();//换行
    }
    for (int i = 3; i >0; i--) {//通过循环打印下半区
      for (int k = 1; k <= 4-i; k++) {
        System.out.print(" ");
      }
      for (int j = 2*i-1; j >0; j--) {
        System.out.print("*");
      }
      System.out.println();
    }
  }

}