Can't get Eclipse 3.3 to compile servlets

Question

Hi,
This is my first time tyring to compile a servlet in Eclipse 3.3. I have serveral errors like "Can not resolve import javax.servlet..." I did include the location of the servlet-api.jar file in my classpath. And not just classpath but I included the location to variables PATH, JAVA_HOME just in case but still no luck. I have browsed the web enough, and tried all the tricks of the trade. I am using jdk1.6_02 and tomcat 5.5.25.
Can anybody help,
Thanks in advance!
Codesingh!

Answer 1

Okay, let's start simple: An instance of Comparable<T> can be compared to instances of T (for any type T). Lets assume Numbers were Comparable:
class Number implements Comparable<Number> { /* ... */ }
class Integer extends Number { /* ... */ }
class Float extends Number { /* ... */ }This means an Integer can be compared to any Number, such as a Float or another Integer:
Integer ten = 10;
Integer five = 5;
ten.compareTo(five);Now let's write a generic function that can sort lists of items that are comparable with each other:
public static <T extends Comparable<T>> void sort(List<T> list) { /* ... */ }If you tried to pass a List<Integer> to sort, you would essentially substitute Integer for T, however Integer does not satisfy the upper bound of Comparable<Integer>. If we substitute Integer in the declaration you provided in reply 2
public static <T extends Comparable<? super T>> void sort(List<T> list) { /* ... */ }we get an upper bound of Comparable<? super Integer>. You're free to substitute "? super Integer" with a supertype[1] of Integer, such as Number and since Integer implements Comparable<Number> the substitution is valid and the call is legal.
Generics are all about substituting.. ;)
To answer the question of what does T extends Comparable<? super T> mean: It means you may substitute any type U for T where U is comparable to a supertype[1] of U.
With kind regards
Ben
[1] the super- and subtype relations are reflexive, in other words Integer is a supertype and a subtype of Integer.