code: private Font randomFont() {
          Random r = new Random();
          int index = r.nextInt(this.fontNames.length);
          String fontName = this.fontNames[index];
          int style = r.nextInt(4);
          int size = (this.fontSizeRange > 0 ? r.nextInt(this.fontSizeRange) : 0) + this.fontBasicSize;
          return new Font(fontName, style, size);
      }
docs: 随机生成一种字体
  
  @return 返回随机生成的字体