Java FAQ: Top Questions

59. What is bytecode manipulation in Java?

Bytecode manipulation involves modifying or generating Java bytecode at runtime or compile-time, often using libraries like ASM or Byte Buddy, to alter class behavior.

Tools: ASM (low-level), Byte Buddy (high-level), Javassist.
Process: Read, modify, or create .class files.
Use Case: AOP (Aspect-Oriented Programming), profiling, mocking frameworks.
Challenges: Requires understanding JVM bytecode instructions.

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