Reading the api documentation

Question

when extending a class you need to override and provide a few functions for things, how do you read the api to determine which functions you need override and which you don't have to unless you want to?
thanks

Answer 1

You have three cases to consider, none-abstract, empty methods, such as java.awt.Canvas
A quote from the second paragrath of the Canvas API documents
An application must subclass the Canvas class in order to get useful functionality such as creating a custom component. The paint method must be overridden in order to perform custom graphics on the canvas.
Abstract classes, such as java.util.AbstractList. Now if we take a quick look at the method summary:
boolean   equals(Object o)
          Compares the specified object with this list for equality.
abstract[b] Object      get(int index)
Returns the element at the specified position in this list
Finally we have interfaces, every thing in an interface needs to be implemented.