Do I need to synchronize a singleton just for reads?

Question

Hello forum. Here's my situation: I keep config data for pages on my website in an XML file, I load said XML file in a startup servlet, creating a JDOM Document object, accessed by a singleton.
Every time a page is loaded, the page accesses this Document object via the singleton, sees whether the page is secure, which template it should use, a bunch of stuff.
Now, because the Document object is created when the context is started, and is never written too, only read, do I need to synchronize it?
I read "Threading lightly, Part 1: Synchronization is not the enemy," on ibm.com (http://www-128.ibm.com/developerworks/java/library/j-threads1.html) in hopes of answering my own question, and the most relevant paragraph states:
"If you are writing data that may be read later by another thread, or reading data that may have been written by another thread, then that data is shared, and you must synchronize when accessing it."
But does my scenario fit? Yes I'm writing data that will be read by another thread, but no thead is accessing this data until the context is fully loaded and the object is fully instantiated. The object is not being written to by threads asynchronously... I just run the risk of it being read at the same time. Do I need to synchronize? If so... having synchronized variables in a servlet environment is bad, so what other approach should I take?
Thanks for your help.

Answer 1

But does my scenario fit? Yes I'm writing data that
will be read by another thread, but no thead is
accessing this data until the context is fully loaded
and the object is fully instantiated. The object is
not being written to by threads asynchronously.If all the writing is complete before any of the reading starts, then there's no need to synchronize the reading.
.. I
just run the risk of it being read at the same time.There's no risk in multiple concurrent reads.
Do I need to synchronize? If so... having
g synchronized variables in a servlet environment is
bad, so what other approach should I take?Couple minor points:
* You don't have synchronized variables. You have synchronized blocks and methods.
* Using synchronization in a servlet context isn't in and of itself necessarily bad. Having multiple requests sync on the same lock can hurt response time, so try to avoid it, and if you must do it, keep the critical sections as small as possible.