Is paranamer supposed to work on Android ?

[om26er]

I tried paranamer on Android but it does not work. Is this library supposed to work on Android ? below is my code.

Paranamer paranamer = new DefaultParanamer();
for (Method method: MainActivity.class.getDeclaredMethods()) {
    String[] names = paranamer.lookupParameterNames(method, false);
    // This is always zero.
    System.out.println(names.length);
    for (String name: names) {
        System.out.println(name);
    }
}

[paul-hammant]

Java sources compiled directly to Dalvik bytecode will not work with BytecodeReadingParanamer specifically, no. That's because ASM (which it relies on at runtime) does not work with Dalvik bytecode.

The original mode of operation used generated tables of data in the same class files - https://github.com/paul-hammant/paranamer#feeding-defaultparanamer. That's standard Java's bytecode format again. If your app compiles to standard Java bytecode the and that is then translated into Dalvik bytecode then those sections will be preserved. That's the way the Android toolchain used to work. See https://www.guardsquare.com/en/blog/the_upcoming_jack_and_jill_compilers_in_android. More recently the Android compiler has change to support Java8 syntax and skips the standard Java intermediate, so we're back to no again. No matter Java8 has it's own APIs that negate the need for Paranamer completely so you should use them.

Some of the other specialized Paranamer implementations should work just fine on android (via reflection, although that comes with a speed cost on Android).

Pull Requests accepted if you think enhancements could be made.