I'am using spring rest web service.Its working fine.But it is slow on first request of each day.After that, all the calls are working great.Problem is only with the first call of the day.Please help.Thanks in advance.
Depending on your architecture and deployment, about a million things could contribute to this :-) I am going to assume the web application is not shut down overnight, because that would be too obvious :-)
Still, all kinds of pools (thread pools, db connection pools, etc) might have spun down to near empty due to inactivity. The OS might have swapped out the pages of your JVM. DNS caches must have expired, so actual DNS lookups are needed again between every component in the system you identify with a domain name instead of a hardcoded IP. Same for ARP caches on endpoints and interim L2 switches.
So the simplest thing you can do is "keep the engine running", issue a periodic GET request from cron or quartz. Or just a "warmup" one every morning right before the start of business day.