java cron solution with completion checking -


i looking simple cron-type solution java-application.

i looked @ cron4j, can set method execute, example every 5 minutes.

only, have custom requirement that, if previous method call still running, should not start simultaneous call, skip call , try again in 5 mins, etc --- i.e. want make sure never run 2 threads same job in parallel. if previous method-call has completed, should new 1 start.

what easiest/most stable way implement requirement in java? (doesn't have cron4j if there better way)

i prefer cron4j because believe it's lightweight , easy use. use application-scoped method perform synchronization.

for instance, if application distributed, jobs details must stored on shared storage, database. in database, can set flag (i.e. column value each job details) indicates if job being executed. , then, next execution time (i.e. column value, , find having column holding next execution flag helpful, should give try if haven't already) should modified adding whatever offset like.

if application isn't distributed, can use synchronized static method or static reentrantlock instance control synchronization.


Comments

Post a Comment

Popular posts from this blog

html - How to style widget with post count different than without post count -

i have border below li elements in wordpress widget types appropriate. element inside set block gives them nice easy click full width. the problem, when choose option "show post count" when adding widget such categories or archives displays post count plain text after tag , because tag block pushes post number text line below. whether choose show post count or not show post count still gives exact same element identifyer example "widget_categories". how style post count not on next line still keep links non post count list items full width? here's example on sidebar www.bbmthemes.com/themes/modular/blog-standard/ in order solve problem need remove display:block; for ul.widgets ul a , add in it's place line-height: 33px; what going achieve have same visual effect. what going lose doing links going work on text , not on "box". the other way out of find post count coming , make changes this. example change text count i
Read more

How to remove text and logo OR add Overflow on Android ActionBar using AppCompat on API 8? -

have researched death , cannot find answer. i have actionbar using appcompat. supporting api v7 (api v8 do). actionbar works api v11. api < v11 has problem of removing icon (and feature) actionbar without supplying overflow. big picture have app logo, app title, , 3 icons squidging same actionbar on low end phone. trying make room! i happy 1 of 2 solutions. either: a method of getting overflow functionality can retrieved pull down. (preferred) method of removing icon , text actionbar below current xml api 11+: <resources> <!-- base application theme api 11+. theme replaces appbasetheme res/values/styles.xml on api 11+ devices. --> <style name="appbasetheme" parent="theme.appcompat.light.darkactionbar"> <item name="android:actionbarstyle">@style/liteactionbarstyle</item> <item name="actionbarstyle">@style/liteactionbarstyle</item> </st
Read more

javascript - storing input from prompt in array and displaying the array -

i want take the inputs user prompt, store input in array, , display it. want take 10 inputs user using for loop. have tried do-while shown below. var givennames = new array(); var pattern = /[\w\d]{1,}/ig; do{ var name = prompt("enter names. letters , digits accepted!\nentering empty field stops asking",""); if(name && name.match(pattern)){givennames.push(name);} } while(name != ""); function displaynames(){ if(givennames.length > 0){ document.getelementbyid("list").innerhtml = "<span style='color:navy;font- weight:bold;'>given names are:<\/span><br><br>" + givennames.join("<br><br>"); } else { document.getelementbyid("list").innerhtml = "<span style='color:navy;font-weight:bold;'>nothing has been given!<\/span>"; } } how replace for loop? var givennames = new array();
Read more