Scope issues concerning conditional assignment for an ArrayList

Question

I'm trying to deal with a number of different cases in my code dependent on attributes pulled from the HTTPRequest object. The thing is, different data gets pulled to fill the ArrayList dependent on the Request stuff, but the format is the same.

if (request.getAttribute("timePeriod").equals(null)) {
    ArrayList<ArrayList<MyWeirdObject>> HM = Test.getGlobalChallenge();
}
else {
    ArrayList<ArrayList<MyWeirdObject>> HM = Test.getGlobalChallengeByMonth(Test);
}

If I don't initialize it before assignment, the code (in a JSP) says - of course - that it can't resolve the HM object.

ArrayList<ArrayList<MyWeirdObject>> HM = new ArrayList<ArrayList<MyWeirdObject>>();
if (request.getAttribute("timePeriod").equals(null)) {
    ArrayList<ArrayList<MyWeirdObject>> HM = Test.getGlobalChallenge();
}
else {
    ArrayList<ArrayList<MyWeirdObject>> HM = Test.getGlobalChallengeByMonth(Test);
}

But if I initialize it, it complains about duplicate local variables. How can I set this to initialize/assign differently based on different situations?

Answer 1

Don't declare the ArrayList again inside the if blocks.

ArrayList<ArrayList<MyWeirdObject>> HM;
if ((request.getAttribute("timePeriod") == null) {
    HM = Test.getGlobalChallenge();
}
else {
    HM = Test.getGlobalChallengeByMonth(Test);
}