Additional Notes
Why is MethodHandle.invokeExact close to native execution speed?
Track: Java
Topic: Reflection API
Focus: MethodHandles
Java: MethodHandles
Answer
It uses precise type matching and JVM optimizations.
The invokeExact method requires exact type matching for arguments and return types, which allows the JVM to optimize the method call to a degree similar to direct method invocation. This type safety lets the JVM perform aggressive optimizations, making it nearly as fast as calling the method directly in Java. For example, if you have a MethodHandle that represents a String method, invokeExact would need the exact parameters matching the String method signature.
The invokeExact method requires exact type matching for arguments and return types, which allows the JVM to optimize the method call to a degree similar to direct method invocation. This type safety lets the JVM perform aggressive optimizations, making it nearly as fast as calling the method directly in Java. For example, if you have a MethodHandle that represents a String method, invokeExact would need the exact parameters matching the String method signature.
Topics: Java MethodHandles Reflection API