Frequently Asked Questions

About javaRuntype

  1. Where does javaRuntype come from? Is it made or backed by any software company?
  2. What is javaRuntype's relation to the op4j project?
  3. Is it stable? Can it be considered production-ready?
  4. Does javaRuntype offer any type of commercial support?
  5. How can I contribute to javaRuntype?

General

  1. What is javaRuntype useful for?
  2. Which is the difference between using javaRuntype's Types and standard java.lang.Class objects?
  3. Which is the difference between using javaRuntype's Types and standard java.lang.reflect.Type objects?

About javaRuntype

Where does javaRuntype come from? Is it made or backed by any software company?

javaRuntype is Open Source Software. It is neither made nor backed by any software (or any other type of) company, and it is offered to the public totally free of charge, both in binary and in source code forms, under the Apache License 2.0.

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What is javaRuntype's relation to the op4j project?

javaRuntype was conceived at first as a part of the op4j project [http://www.op4j.org], and by the same person who created op4j itself, but later during op4j's development it was decided that javaRuntype should be a project of its own as its range of application by separate was in fact quite broad.

So, javaRuntype remains today as a useful and required dependency for op4j, but it can also be used without op4j at all for several different purposes.

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Is it stable? Can it be considered production-ready?

Yes, all of its non-beta releases can be considered stable and production-ready.

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Does javaRuntype offer any type of commercial support?

No, it does not.

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How can I contribute to javaRuntype?

In many ways:

  • You can write to the Team with your ideas for improving javaRuntype.
  • You can contribute some code, write a patch for a new feature or behaviour (please, tell the project admins first about your idea so that effort can be correctly coordinated).
  • You can write articles, reviews, blog posts, etc. about javaRuntype, showing how it works or how it integrates with other technologies.
  • You can promote javaRuntype in your company/work and among your colleague developers.

If you want to contribute some code to javaRuntype, please read first the page on Contributing to javaRuntype.

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General

What is javaRuntype useful for?

javaRuntype is mainly useful for metadata systems, in order to be able to declare types for objects in a complete way, retaining in runtime the same features that Java types offer in compile time.

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Which is the difference between using javaRuntype's Types and standard java.lang.Class objects?

Standard java.lang.Class objects, although easily obtainable from any object at runtime, lack all the generics information that the object could have been assigned at compile time. For example, a "List<String>" object will just be a "java.util.List" object at runtime, and there will be no way to bring back the generics information (the "of String" part). There is in fact no java.lang.Class object in the VM for "List<String>", just for "List".

This is quite often a problem for metadata-based systems, which javaRuntype tries to solve.

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Which is the difference between using javaRuntype's Types and standard java.lang.reflect.Type objects?

Standard java.lang.reflect.Type objects can only be obtained as the result of applying reflection on methods or classes, and they will only specify the types of method results, method parameters, class definitions and other "code-wired" artifacts.

But these java.lang.reflect.Type objects cannot be obtained freely for its use (you cannot say to the VM: "I want the java.lang.reflect.Type object representing List<String>"), and they do not offer a truly useful operations API. They are more a type system documentation artifact, while javaRuntype's types are easy-to-use, useful type system tools.

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