On 1/26/11 11:37 PM, Christopher Schultz wrote: > Blake, > > On 1/26/2011 4:05 PM, Blake McBride wrote: >> The first time a particular web service is called tomcat starts a thread to >> run it on and creates an instance of the class that implements the web >> service. All fine. However, if after the first call to the web service >> completes another call to the same web service occurs, tomcat reuses the >> same thread and the same instance. Of course this gives me old values for >> thread local storage and instance variables for that web service. > > Oh noes!!!111!!!ELEVEN > > Seriously, this is how the server world works. > >> This is highly unexpected. > > Perhaps by you, but this behavior is entirely intentional. > >> Is there a way to configure tomcat to have it give me a new instance of the >> web service class each time? > > That depends: when you say "web service", what do you mean? Are you > using a library like Apache Axis or do you have a (relatively) simple > servlet handling the requests? > > The rules of thumb are: > > 1. Don't use ThreadLocal unless you > a) Know what you're doing > b) Clean up after yourself > and > c) Know what you're doing
+1 Axis 1.4 has issues in this regard. p > 2. Don't use any class members that aren't expected to be used for all > requests for all time. Basically, that means don't use them. Instead, > use locals in your service() (or doGet/doPost/whatever) method > and/or use request attributes to store your data. > >> In terms of the repeated thread use and thread local storage I have, for the >> time being, started manually resetting the thread local storage. Is there a >> conventional solution to this problem? > > Your thread should reset ThreadLocals when you're done using the thread: > at the end of the request. Don't forget to handle error conditions and > clean up in finally blocks. > > Why are you using ThreadLocals in the first place? The only legitimate > uses I've seen for them are performance optimizations where the > ThreadLocal actually /should/ outlive the request and weird stuff like > passing data to Log4j loggers through lazy API (non-)usage. I'm not > convinced ThreadLocals are a good idea at all. > > -chris --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
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