Mark
asked on
How to reference "global" variable in java function.
I have a function, referenced by numerous other programs, whose parameters are not able to be changed:
static void reportDetail(Statement stmt, BufferedWriter outFile, String detailColumn) throws Exception
However, the body of the function is defined locally in any given program. What I need to do in one particular program is reference a string defined in the main program, e.g.:
String localVar = globalVar;
where globalVar is defined outside the scope of reportDetail().
Is there a way to do this? (this is jsp BTW)
static void reportDetail(Statement stmt, BufferedWriter outFile, String detailColumn) throws Exception
However, the body of the function is defined locally in any given program. What I need to do in one particular program is reference a string defined in the main program, e.g.:
String localVar = globalVar;
where globalVar is defined outside the scope of reportDetail().
Is there a way to do this? (this is jsp BTW)
ste5an
You don't. Cause global variables represent state, which is a big problem when you need to test your function. Take a look at this excellent video about it.
Is it a constant?
ASKER
CEHJ
Is it a constant?No. In fact it is the UserAgent string obtained in the main body of the jsp program.
btw, such a value belongs to the model in MVC or the view model in MVVM.
ASKER
ste5an: I don't know what you mean. Please explain.
ASKER
To be specific, I need a way of getting the UserAgent string: (request.getHeader( "User-Agent" ), in a function without passing it as a function parameter.
I don't see how such a thing could work - unless you've managed to deploy your web app such that concurrent access is impossible. Otherwise, how would you know from which request the 'global' User-Agent string originated?
ASKER
User-Agent is set on a per-request basis depending on which browser the user uses. By global, I mean global to programs in that session, not global to ALL sessions persistent over all time.
I could open a file in the main body, write the User-Agent info to it, then open that file in the function, but surely there is a better way!
I could open a file in the main body, write the User-Agent info to it, then open that file in the function, but surely there is a better way!
If you're just talking about the session, if you can get the Request then you can get the User-Agent header
ASKER
The problem is that the request object is not available to the function unless I add it to the parameter list as in:
static void reportDetail(Statement stmt, BufferedWriter outFile, String detailColumn, HttpServletRequest request) throws Exception
which I can't do without changing LOTS of programs, just for this one special case.
static void reportDetail(Statement stmt, BufferedWriter outFile, String detailColumn, HttpServletRequest request) throws Exception
which I can't do without changing LOTS of programs, just for this one special case.
This question needs an answer!
Become an EE member today
7 DAY FREE TRIALMembers can start a 7-Day Free trial then enjoy unlimited access to the platform.
View membership options
or
Learn why we charge membership fees
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.