使用递归做到1个for循环打印菱形

private static void printDia(int lineNumber) {if(lineNumber%2==0)throw new RuntimeException("不支持偶数菱形");StringBuilder sb = new StringBuilder();boolean flag = false;for(int i=0;i>=0;i++){if(i==lineNumber/2)flag=true;append(i,lineNumber/2,sb," ");append(0,2*i+1,sb,"*");System.out.println(sb.toString());sb.delete(0, sb.length());if(flag)i=i-2;}}private static void append(int start, int condition, StringBuilder sb, String content) {if(start<condition){sb.append(content);append(++start,condition,sb,content);}}