OE-3.3 Exceptions, Multithreading & Generics
You can handle and define exceptions, create and synchronize threads, and write generic classes, methods and interfaces with bounded types.
Checked versus unchecked exceptions is a Java-specific design decision that shapes how its libraries feel; understand the try/catch/finally flow precisely, especially what finally guarantees. Thread synchronization is the part that will bite you in real code - a race condition passes tests and fails in production, so learn why synchronized exists before learning its syntax. Generics were added to move type errors from run time to compile time, and that single sentence explains most of their design.
Work through these
Exception types; try, catch, throw, throws and finally
How failure is signalled and handled, and the five keywords that do it. The distinction between what you must handle and what you need not is the one to get straight.
Writing your own exception classes
Defining your own error types, so a caller can respond to one problem without catching everything. It is the difference between error handling and error suppression.
The Java thread model; how to create threads; the Thread class
Doing more than one thing at once, and the two ways the language offers to start. The model matters more than the syntax because the hazards come from the model.
NPTEL: Programming in Java · CourseThread priorities and thread synchronization
Deciding what runs when, and stopping two things touching the same data at once. Synchronisation is where concurrent programs actually go wrong, so this item carries more weight than its length.
Generic classes and bounded types
Types as parameters, so one class can work with many types without losing safety. Bounded types are what let the generic code still call methods on what it holds.
Generic methods and interfaces
The same idea applied to a single method or an interface. It is what makes the collections in the next topic usable without casting everywhere.
Sign in to keep your progress.
Free resources
We haven't checked most of these for screen reader use yet.
Links last checked 30 Aug 2026.
Stuck here?
Ask a mentor. A real person answers, and they can see exactly which topic you're on. Usually within a couple of working days.
Checking your session…
Topics shown in module order.