对于给定的n,输出2n+1行,2n+1列星号。n=2 (用Java编程)答:public class Example2_14 { public static void main(String args[]) { int n,j,k,space;String result=(String)JOptionPane.showInputDialog(null,"请输入一个整数","输入对话框",JOptionPane.PLAIN_MESSAGE,null,null,null);n=Integer.parseInt(result);space=40;for(j=0;j<=n;j++,space-=...