LDAP Context Initialization Problem in a Servlet's Init method

Question

Hi
I have a servlet where I am using the InitialDirContext to Initialize context to a LDAP Server. I have created the context as a static variable. I am initializing the context in the init method and am using the same reference in the service method of the servlet. But if the context fails (due to naming exception and time out) in the init method all my requests in the service method will fail. Is there any way to validate the reference before using the same in the service method.
Also what is the best approach to initialize the context in a servlet. Whether to initialize in the service method or the init method.
I would appreciate if anyone can answer the above 2 queries.
Thanks in advace,
Ashish

Answer 1

If you want to use threadsafe objects in doPost/doGet there are two common ways to do this.
First, create the object in doPost/doGet. This may get expensive depending on the object, but it is 'easy' code and works.
The second option is to create a pool of objects in the servlet's init() method and to just have doPost/doGet get an object from the pool, use it and return it when done. This take a little more work to code, but the overhead of creating objects is almost eliminated. Look at jakarta/apache commons pool for a quick way to do this.
If you create on object in init() and use it in doPost/doGet, any time you get two request for the same servlet at the same time you will have synchronization issues that will usually cause problems. There is one instance of each Servlet, so all request for that servlet go through the single instance. Anything in doPost/doGet must be threadsafe.