Exception Handling

11 Topics

Exceptions Basics

Examine runtime exception anomalies, JVM stack unwinding search algorithms, and the Throwable hierarchy.

Focuses on Throwable root hierarchy, differences between Exception and Error, and the JVM call stack unwinding process.

try-catch Block

Master try-catch syntax structures, catch block inheritance ordering rules, and clean exception re-throwing.

Frequently tested: catch block ordering compiler rules, unreachable catch block errors, and exception re-throwing with cause.

finally Block

Analyze finally guaranteed execution loops, resource cleanups, non-execution edge cases, and return value overrides.

Highly tested: return statement inside finally (swallowing exceptions), finally execution guarantees, and System.exit edge cases.

throw Keyword

Deconstruct explicit exception throwing, stack trace capture costs, and flow control limits.

Evaluates the execution overhead of instantiating Exception objects (fillInStackTrace) and when to throw custom exceptions vs standard ones.

throws Keyword

Analyze throws signature declarations, exception propagation routes, and overriding variance rules.

Evaluates rules for checked exception inheritance during method overriding (narrower/fewer allowed, broader/new prohibited).

Checked vs Unchecked Exceptions

Conduct a comparative analysis of checked vs unchecked classifications, recoverability, and library designs.

Highly tested: Exception classification criteria (recoverable vs programming bug), standard checked/unchecked class roots, and framework design preferences.

Custom Exceptions

Design custom checked and unchecked exception classes, declare constructors, and handle chaining causes.

Evaluates custom exception class design, extending Exception vs. RuntimeException, and writing constructors that support exception chaining.

Exception Hierarchy

Map the Throwable class hierarchy structure, separate Errors from Exceptions, and map JVM errors.

Evaluates the java.lang.Throwable tree layout, distinguishing Error from Exception, and positioning of RuntimeException.

try-with-resources

Master AutoCloseable resource management, reverse closing sequences, and suppressed exception tracking.

Highly tested: AutoCloseable close() execution sequence, suppressed exceptions (getSuppressed), and try-with-resources vs. try-finally.

Multi-catch Block

Dissect multi-catch syntax, implicit final variable declarations, and type inheritance compiler rules.

Evaluates multi-catch syntax, the implicit final modifier constraint, and inheritance exclusions (cannot catch child and parent together).