final

Today my colleagues and me have a discussion about the usage of the final keyword in Java to improve the garbage collection. For example, if you write a method like: public Double doCalc(final Double value) { final Double maxWeight = 1000.0; final Double totalWeight = maxWeight * value; return totalWeight; } Declaring the variables in the method final would help the garbage collection to clean up the memory from the unused variables in the method after the method exits. Is this true? Here's a slightly different example, one with final reference-type fields rather than final value-type local

Because I believe it is a good programming practice, I make all my (local or instance) variables final if they are intended to be written only once. However, I notice that when a variable assignment can throw an exception you cannot make said variable final: final int x; try { x = Integer.parseInt("someinput"); } catch(NumberFormatException e) { x = 42; // Compiler error: The final local variable x may already have been assigned } Is there a way to do this without resorting to a temporary variable? (or is this not the right place for a final modifier?) One way to do this is by introducing a

Okay, so say I have a class that looks like this : public class SignupServlet extends HttpServlet { private static final Logger SERVLET_LOGGER=COMPANYLog.open(SignupServlet.class); private static final ExceptionMessageHandler handler = new ExceptionMessageHandler(); private static final SignupServletObservableAgent signupObservableAgent = new SignupServletObservableAgent(null, SERVLET_LOGGER); } Can I count on the class loader to initialize those fields in order, such that I can rely on SERVLET_LOGGER to be instantiated before signupObservableAgent? Laurence Gonsalves Yes, they are initialized

I was told that static methods are implicitly final and therefore can't be overridden. Is that true? Can someone give a better example of overriding a static method? If static methods are just class methods, what is the real use of having them? (1) Static methods cannot be overridden, they can however be hidden using the 'new' keyword. Mostly overriding methods means you reference a base type and want to call a derived method. Since static's are part of the type and aren't subject to vtable lookups that doesn't make sense. E.g. statics cannot do: public class Foo { public virtual void Bar() {

I have an array of seats, and the array has two strings(selected and empty). On mouse click, I want to traverse the array and find the selected seat. When I press the button it says: The final local variable seatno cannot be assigned, since it is defined in an enclosing type. JButton btnContinue = new JButton("Next"); btnContinue.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent arg0) { for(int x=0;x<17;x++){ if(anArray[x]=="selected"){ seatno = anArray[x]; } } data page=new data(newfrom,newto,newtime,date2,seatno); page.setVisible(true); setVisible(false); } });