java timer 一天中4个固定的时间执行Task，但是4个时间之间没有特定的关系是任意的时间，怎么做？

你好，利用以下方法可以实现：
oid java.util.Timer.scheduleAtFixedRate(TimerTask task, long delay, long period)

scheduleAtFixedRate
public void scheduleAtFixedRate(TimerTask task,
long delay,
long period)

Schedules the specified task for repeated fixed-rate execution, beginning after the specified delay. Subsequent executions take place at approximately regular intervals, separated by the specified period. In fixed-rate execution, each execution is scheduled relative to the scheduled execution time of the initial execution. If an execution is delayed for any reason (such as garbage collection or other background activity), two or more executions will occur in rapid succession to "catch up." In the long run, the frequency of execution will be exactly the reciprocal of the specified period (assuming the system clock underlying Object.wait(long) is accurate).
Fixed-rate execution is appropriate for recurring activities that are sensitive to absolute time, such as ringing a chime every hour on the hour, or running scheduled maintenance every day at a particular time. It is also appropriate for recurring activities where the total time to perform a fixed number of executions is important, such as a countdown timer that ticks once every second for ten seconds. Finally, fixed-rate execution is appropriate for scheduling multiple repeating timer tasks that must remain synchronized with respect to one another.

最最最简单的方法：建立四个Timer来执行Task，每个Task的执行周期都是一天。

timer.execute(task,waitTime,period);// 在某个时间段之后执行任务