Can we avoid heavy reflection usage for Converters?

[geoand]

When creating a ConfigMapping, converters are looked up via Converters.Implicit.getConverter((Class<?>) clazz) which looks like:

        static <T> Converter<T> getConverter(Class<? extends T> clazz) {
            if (clazz.isEnum()) {
                return new HyphenateEnumConverter(clazz);
            }

            // implicit converters required by the specification
            Converter<T> converter = getConverterFromStaticMethod(clazz, "of", String.class);
            if (converter == null) {
                converter = getConverterFromStaticMethod(clazz, "of", CharSequence.class);
                if (converter == null) {
                    converter = getConverterFromStaticMethod(clazz, "valueOf", String.class);
                    if (converter == null) {
                        converter = getConverterFromStaticMethod(clazz, "valueOf", CharSequence.class);
                        if (converter == null) {
                            converter = getConverterFromStaticMethod(clazz, "parse", String.class);
                            if (converter == null) {
                                converter = getConverterFromStaticMethod(clazz, "parse", CharSequence.class);
                                if (converter == null) {
                                    converter = getConverterFromConstructor(clazz, String.class);
                                    if (converter == null) {
                                        converter = getConverterFromConstructor(clazz, CharSequence.class);
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return converter;
        }

In a Quarkus context, we already know this information and could pass it to Smallrye Config, right?

[radcortez]

Yes, it can be done.

I made some improvements recently here:
quarkusio/quarkus#44921

Of course, this can also be improved. We already provide converters for the most common types, so this code is not used often. I did find 3 invocations in the config-quickstart, because of File, URI, and InheritableLevel.

I'll have a look.

[geoand]

Those are exactly the ones I saw as well!