public class Main { public static void main(String[] args) { double d = 3.1415926; System.out.printf("%.2f\n", d); // 显示两位小数3.14 System.out.printf("%. ...
传统javascript：The text is inserted in the value attribute. On focus, it checks if the value is "search" and returns empty to clear the field. If the value is empty, it returns "search." As you can see, this way is not an efficient way because each field has to be checked.Now with
在spring中是用profiles来区别不同的环境，在profile中应用数据库配置信息出现了Could not resolve placeholder 'jdbc.url' in string value "${jdbc.url}"这样的提示，原因是之前配置了占位符bean class="org.springframework.beans.factory.config.
