CODEWITHSUNDEEP
javaclojure
zcaudate
zcaudate

Reputation: 14258

Is there a way to create a java class type programmatically?

Is there a way of using reflection to create a class programmatically? For instance. Is there a private constructor we can use to create a class type that then can be used to create instances of that class?

I know that there are other tricks like generating source code and compiling it, or generating byte code and loading it using a classloader... But I want to see if it is possible to somehow create an instance of java.lang.Class directly.

I want to write the following code in clojure:

(def c (create-class "com.example.Dog" {:fields {"legs" 4}
                                        :methods {"bark" (... do something ...)}
                                        :constructors {.....}}))

(def d1 (.newInstance c))
(def d2 (.newInstance c))

Upvotes: 1

Views: 353

Answers (1)

Arthur Ulfeldt
Arthur Ulfeldt

Reputation: 91607

Clojure has several ways to generate classes depending on your needs: They are described in the Clojure types page Though I found the chapter on types in Clojure Programming most helpful as a comparison of the various ways of generating classes dynamically.

  • defrecord
  • deftype
  • proxy
  • gen-class
  • protocols
  • reify

Under the hood these generate bytecode and load it using a classloader (except for gen-class) which writes class files. There is a lot more to the subject than I can cover here, it's well worth checking out the chapter in Clojure Programming (or your favorite Clojure Book)

Upvotes: 4

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