去哪儿网机票搜索系统的高并发架构设计
生成随机id
// 需要引入import java.util.UUID包 public static String getUUID() { UUID uuid = UUID.randomUUID(); String str = uuid.toString(); String uuidStr = str.replace("-", ""); return uuidStr; }
HTML元素禁用的方法
禁用radio,设置为只读,不能选定 <input type="radio" name="gender" value="1" disabled/><span >男</span> <input type="radio" name="gender" value="0" disabled/><span >女</span> ...
计算相差的月数
public static int getMonthDiff(Date d1, Date d2) { Calendar c1 = Calendar.getInstance(); Calendar c2 = Calendar.getInstance(); c1.setTime(d1); c2.setTime(d2); int year1 = c1.get(Calendar.YEAR)...
Java中Array和List的相互转换
Array转List String[] array = {"string1", "string2", "string3"}; List<String> list = Arrays.asList(array); //Arrays.asList产生一个Arrays内置的类,其中数组用final表示 // list.add("string4"); 所以不能往其中添加元素 for(S...
使用Calendar类来输出年份、月份等
import java.util.Calendar; public class Main { public static void main(String[] args) { Calendar cal = Calendar.getInstance(); int day = cal.get(Calendar.DATE); int mon...
在springmvc-servlet.xml中设置上传文件的大小限制
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <!-- 设置上传文件编码 --> <property name="defaultEncoding" value="UTF-8"></...
Oracle 使用SQL语句对序列的操作
创建序列 CREATE SEQUENCE test_seq MINVALUE 1 MAXVALUE 9999999999 START WITH 100000 INCREMENT BY 1 CACHE 20 查询所有序列 select * from user_sequences; 查询特定序列 select * from user_se...
Oracle 使用SQL创建备份表
create table a_bak as select * from a;
Oracle 取查询结果排序后的第一条记录
select * from (select t.*, row_number() over(order by id) rn from test_order t) t where rn = 1;