Why it matters

Understanding reflection matters for framework use and debugging. Also for security consideration.

Advertisement

The architecture

Class object: Foo.class or obj.getClass(). Gateway to reflection.

Methods: class.getMethods(), class.getDeclaredMethods().

Reflection capabilitiesClass objectgatewayReflect membersmethods, fields, ctorsInvoke dynamicallywith parametersMethodHandles are faster than pure reflection; VarHandles for field access
Reflection surfaces.
Advertisement

How it works end to end

Access: setAccessible(true) bypasses private. Requires JPMS opens in modules.

Performance: reflective calls slower than direct. JIT can inline some.

MethodHandles: faster alternative introduced in Java 7.

Records + patterns: modern alternatives reduce reflection need.