java stream 使用局部变量
直接使用是没问题的 public static void main(String[] args) throws IOException { List<String> list1 = Arrays.asList("1","2","3"); List<String> list2 = Arrays.asList("2", "1"); list2.stream().filter( iterm ->
java stream map
返回调用<R> Stream<R>map(Function<? super T,? extends R> mapper)参数是Interface Function<T,R>对象,(需要手动实现Function接口的apply(T t)方法返回类型为R)? super T 是输入的类型? extends R 明确了返回类型为R1.内部类实现方式,写法一:匿名内部类这里Function的泛型<T,R>变成了<S...
java stream flatmap
返回调用<R> Stream<R>flatMap(Function<? super T,? extends Stream<? extends R>> mapper)参数类型是T返回值是Stream 且 Stream的泛型为R(在spark中flatmap的返回值是iterator)1.内部类实现方式,写法一:匿名内部类这里Function的泛型<T,R>变成了<String,String>重写了app...
java stream intermediate&terminal方法
如果不调用terminal方法则不会执行intermediate方法 public static void main(String[] args) throws IOException { List<String> list1 = Arrays.asList("1","2","3"); list1.stream().map( x->{ x += x;
java stream 泛型
调用stream时,必须明确集合的泛型 List list1 = Arrays.asList("1","2","3"); list1.stream().filter(x->x.length()>=1).forEach(System.out::println);//报错,x被当成object来处理要改成 List<String> list1 = Arrays.asList("1","2","3");//指明集合类型是String
java quartz(定时器)
package com;import org.quartz.*;import org.quartz.impl.StdSchedulerFactory;import java.io.IOException;import static org.quartz.JobBuilder.newJob;import static org.quartz.TriggerBuilder.newTrigger;public class clroja { public static class my
java quartz JobBuilder
JobBuilder主要主要用来创建JobDetail,常用两个属性:.withIdentity("job1", "group1") //设置job的名称和分组,以便后期的查找.usingJobData("key","value") // 使用JobData向job中传递参数完整代码演示:package com;import org.quartz.*;import org.quartz.impl.StdSchedulerFactory;import java.io.IOException;
java quartz TriggerBuilder
TriggerBuilder主要用来创建触发器,触发器必须要绑定job才有效1.trigger的jobdata和jobdtail对象的是独立,不是一个package com;import org.quartz.*;import org.quartz.impl.StdSchedulerFactory;import java.io.IOException;import static org.quartz.JobBuilder.newJob;import static org.quartz.
java quartz DateBuilder
Trigger中经常使用Date对象,而DateBuilder是一个提供时间对象的便捷方法1.常规获得时间 System.out.println(DateBuilder.dateOf(12, 30, 30, 13, 12, 2002)); //指定年月日时分秒 System.out.println(DateBuilder.dateOf(12, 30, 30)); //只指定时分秒,自动获得当前日期 System.out.println(DateBuilder
java quartz Scheduler 操作JobDetail
scheduler可以看成是一个容器,对JobDetail进行增删改查//增sched.addJob(job,false);// false表示不替换,ture表示替换,既更新;另外一般使用 比较方便sched.scheduleJob(job, trigger);//查System.out.println(sched.getJobDetail(JobKey.jobKey("job1","group1"))); //获得JobDetailSystem.out.println(sched.getJo
java quartz Scheduler 操作Trigger
//增sched.scheduleJob(trigger);//trigger必须使用forJob绑定JobDetail//查System.out.println(sched.getTrigger(TriggerKey.triggerKey("trigger1","group1")));//通过TriggerKey获得System.out.println(sched.getTriggersOfJob(JobKey.jobKey("job1","group1")));//通过JobKey获得,因为二
java quartz SimpleScheduleBuilder
1.设置时间间隔 SimpleScheduleBuilder.simpleSchedule() .withIntervalInHours()// .withIntervalInMinutes()// .withIntervalInSeconds()2.设置重复次数 SimpleScheduleBuilder.simpleSchedule() .w
java quartz CronScheduleBuilder
CronScheduleBuilder.cronSchedule("0 0 12 ? * WED");Cron表达式总共有7个位置分别是SecondsMinutesHoursDay-of-MonthMonthDay-of-WeekYear (optional field)表达secondsminuteshoursdayofmonthmonthdayofweekyear每周三12点执行0012?*WED1.每个位置可以是范围,可以是列表,
java quartz
java quartz(定时器)java quartz JobBuilderjava quartz TriggerBuilderjava quartz DateBuilderjava quartz Scheduler 操作JobDetailjava quartz Scheduler 操作Triggerjava quartz SimpleScheduleBuilderjava quartz CronScheduleBuilder
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