Question 1

How much faster is ReflectASM compared to standard Java reflection?

Accepted Answer

ReflectASM provides substantial speed improvements, with benchmarks in the README showing up to 10x faster field access and 2x faster method calls, depending on the operation and JVM setup. It uses bytecode generation to bypass reflection overhead.

Question 2

Can ReflectASM access private fields or methods?

Accepted Answer

No, ReflectASM cannot access private members. It attempts to use setAccessible for protected and package-private access, but falls back to public-only if restricted by security managers, as explained in the visibility section.

Question 3

How to use ReflectASM with Maven in a Java project?

Accepted Answer

Add the dependency snippet from the README to your pom.xml, including groupId com.esotericsoftware and artifactId reflectasm. This integrates the library easily, with version 1.11.9 as the latest stable release.

Question 4

What's the best way to handle repeated method calls with ReflectASM for performance?

Accepted Answer

Use index-based access by calling getIndex on the MethodAccess object to precompute the method index, then invoke with that index in loops. This eliminates name lookup overhead, as shown in the 'Avoiding Name Lookup' example.

Question 5

ReflectASM vs Byte Buddy for reflection performance: which is better?

Accepted Answer

ReflectASM focuses solely on high-performance reflection via bytecode generation, making it lighter and faster for direct access. Byte Buddy offers broader features like dynamic proxies and instrumentation, so choose ReflectASM for pure reflection speed, but Byte Buddy for more complex use cases.

Question 6

Does ReflectASM work with Java 9+ modules (JPMS)?

Accepted Answer

It may face issues due to module encapsulation; ReflectASM relies on setAccessible, which can be blocked by module boundaries. You might need to open packages or configure module descriptors to allow access, similar to standard reflection limitations.

Question 7

How to handle exceptions when using ReflectASM for method invocation?

Accepted Answer

If the invoked method throws a checked exception, you must catch Exception broadly, as ReflectASM doesn't declare them. This is highlighted in the README's exception section, making error handling less type-safe compared to direct calls.

ReflectASM

What is ReflectASM?

Overview

Use Cases

Best For

Related Projects

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Pros & Cons

Pros

Cons

Frequently Asked Questions