java 编程题，如下，代码怎么写啊？？？？？

写个sql就行了：天的：select max(t.times)
from (select sysdate - 1 as times
from dual
union all
select sysdate - 1 + 1 / 24 as times
from dual
union all
select sysdate + 3 / 24 as times
from dual
union all
select sysdate - 4 + 3 / 24 as times
from dual
union all
select sysdate - 31 + 2.5 / 24 as times from dual) t
group by trunc(t.times, 'DD');
月的：
select max(t.times)
from (select sysdate - 1 as times
from dual
union all
select sysdate - 1 + 1 / 24 as times
from dual
union all
select sysdate + 3 / 24 as times
from dual
union all
select sysdate - 4 + 3 / 24 as times
from dual
union all
select sysdate - 31 + 2.5 / 24 as times from dual) t
group by trunc(t.times, 'MM')

其中
select sysdate - 1 as times
from dual
union all
select sysdate - 1 + 1 / 24 as times
from dual
union all
select sysdate + 3 / 24 as times
from dual
union all
select sysdate - 4 + 3 / 24 as times
from dual
union all
select sysdate - 31 + 2.5 / 24 as times from dual
是你那里的表；
周的话，没明白你的意思，是每周算一个周期？