GetParameterNames

GetParameterNames is a term used for a utility or API that returns the names of parameters for a callable such as a method, function, or constructor. It is not a universal standard across all languages; different environments provide different mechanisms to obtain parameter names at runtime or through analysis of compiled code.

In Java, there is no single core API method officially named getParameterNames. Historically, parameter names may be unavailable at runtime unless certain conditions are met. If code is compiled with the -parameters option, the reflection API can reveal names via Method.getParameters() and the Parameter.getName() method. Without -parameters, some frameworks attempt to recover names from the local variable table or debug information, using libraries such as Paranamer. Obfuscation or aggressive optimization can remove or rename parameter information, making retrieval unreliable.

Typical usage involves obtaining a callable’s metadata and iterating over the parameters to read their names. For example, one would obtain a Method object, call getParameters() to receive Parameter objects, and then query each Parameter for its name and type. This information is valuable for dependency injection, parameter binding, code generation, and tooling that performs reflective invocation or API binding.

Beyond Java, other languages offer similar capabilities with differing APIs. In Python, libraries like inspect provide parameter names via signature or fullargspec; in JavaScript, parameter names can sometimes be inferred by parsing a function’s source, though this is not reliable across environments.

Common limitations include lack of names in compiled artifacts, name obfuscation, and potential performance costs. When available, parameter names aid debugging, error reporting, and dynamic frameworks, but should be used with awareness of their provenance.