java - Jms session.recovery meaning -

-



i investigating jms api

i misunderstand following method meaning:

https://docs.oracle.com/javaee/7/api/javax/jms/session.html#recover--

void recover() throws jmsexception
stops message delivery in session, , restarts message delivery oldest unacknowledged message. consumers deliver messages in serial order. acknowledging received message automatically acknowledges messages have been delivered client.

restarting session causes take following actions:

stop message delivery mark messages might have been delivered not acknowledged "redelivered" restart delivery sequence including unacknowledged messages had been delivered. redelivered messages not have delivered in original delivery order. throws: jmsexception - if jms provider fails stop , restart message delivery due internal error. illegalstateexception - if method called transacted session.

in another doc written:

if use queue or durable subscription, can use session.recover method stop nontransacted session , restart first unacknowledged message. in effect, session’s series of delivered messages reset point after last acknowledged message. messages delivers may different delivered, if messages have expired or if higher-priority messages have arrived. nondurable topicsubscriber, provider may drop unacknowledged messages when session recovered.

but still unclear happens. maybe real use case can understand.





wiki

Comments

Post a Comment

Popular posts from this blog

Asterisk AGI Python Script to Dialplan does not work -

-
i'm stuck project have check database of sip extension incoming caller id , dial sip extension. below receive when run script on asterisk cli. -- registered sip '9125' @ 192.168.1.102:50142 > saved useragent "zoiper rv2.8.40" peer 9125 [2017-08-22 13:53:33] notice[5095]: chan_sip.c:24558 handle_response_peerpoke: peer '9125' reachable. (17ms / 2000ms) == using sip rtp tos bits 184 == using sip rtp cos mark 5 -- executing [0112617769@from-trunk:1] answer("sip/obitrunk1-0000000d", "") in new stack > 0x1ca50d0 -- probation passed - setting rtp source address 192.168.1.98:16834 -- executing [0112617769@from-trunk:2] agi("sip/obitrunk1-0000000d", "test.py") in new stack -- launched agi script /var/lib/asterisk/agi-bin/test.py args: ['/var/lib/asterisk/agi-bin/test.py'] env line: agi_request: test.py env line: agi_channel: sip/obitrunk1-0000000d env line: agi_language: en env line: a
Read more

python - Read npy file directly from S3 StreamingBody -

-
i have many .npy (numpy) , .json files saved in s3, need download , load these files. for json files downloading files , loading dictionary using following code: obj = s3.object(bucket, key) response = obj.get() body = response['body'].read().decode('utf-8') data = json.loads(body) that way avoid writing .json file disk , reading it. now want same .npy files, equivalent? currently downloading file, saving temp file on disk , loading np.load avoid if possible. following https://stackoverflow.com/a/28196540/3509999 : obj = s3.object(bucket, key) io.bytesio(obj.get()["body"].read()) f: # rewind file f.seek(0) arr = np.load(f) wiki
Read more

kotlin - Out-projected type in generic interface prohibits the use of metod with generic parameter -

-
i start using kotlin , defined interface this: interface aadapter<vh : recyclerview.viewholder> { fun oncreateaviewholder(parent: viewgroup): vh fun onbindaviewholder(v: vh, position: int) } and when try use on code: class klasa ( private val adapter: aadapter<*> ) { fun dosth(){ //... val vh = this.adapter.oncreateaviewholder(parent) //on below line error adapter.onbindaviewholder(v, position) //... } } i error out-projected type 'aadapter<*>' prohibits use of 'public abstract fun onbindaviewholder(v: t, position: int): unit i tied add "in" or "out" definition i'm confused. how allow it. replace aadapter<*> aadapter<recyclerview.viewholder> . class klasa ( private val adapter: aadapter<recyclerview.viewholder> ) { // ... because have declared aadapter has type parameter vh type subclass of recyclerview.
Read more