Munich Clojure Workshop - 04 - Java Interop

Copyright © 2012-2014 Clojure Workshop Team: Maximilian Karasz, Jan Stępień, Marek Kubica, Oleksandr Petrov

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Transcript

1. Java Interoperability Friday, October 11, 13
2. Access Java in Clojure Friday, October 11, 13
3. Calling Methods Friday, October 11, 13
4. (.method object) Friday, October 11, 13
5. (.toUpperCase "abc") ;; => "ABC" Friday, October 11, 13
6. (.method object x y) Friday, October 11, 13
7. (.equals "a" "b") ;; => false Friday, October 11, 13
8. (.getName String) ;; => "java.lang.String" Friday, October 11, 13
9. (Class/static-var) (Class/method) (Class/method x) (Class/method x y) Friday, October 11, 13
10. (Math/PI) ;; => 3.141592653589793 (Thread/activeCount) Friday, October 11, 13
11. (.println (System/out) "hello") Friday, October 11, 13
12. (.toUpperCase "abc") (. "abc" toUpperCase) Friday, October 11, 13
13. (Thread/activeCount) (. Thread activeCount) Friday, October 11, 13
14. (.equals "a" "b") (. "a" equals "b") Friday, October 11, 13
15. (.println (System/out) "hello") (. (. System out) println "hello") (.. System out (println "hello")) Friday, October 11, 13
16. (.. Runtime getRuntime availableProcessors) Friday, October 11, 13
17. New Objects Friday, October 11, 13
18. (new Object) (Object.) (java.util.HashMap.) (Integer. 5) Friday, October 11, 13
19. (let [hashmap (java.util.HashMap.)] (.put hashmap "a" "b") (.get hashmap "a")) Friday, October 11, 13
20. (import [java.util HashMap ArrayList]) (HashMap.) (ArrayList.) Friday, October 11, 13
21. (let [hashmap (HashMap.)] (.put hashmap "a" "b") (.put hashmap "x" "y") hashmap) Friday, October 11, 13
22. (let [hashmap (HashMap.)] (.put hashmap "a" "b") (.put hashmap "x" "y") hashmap) (doto (HashMap.) (.put "a" "b") (.put "x" "y")) Friday, October 11, 13
23. (instance? HashMap (HashMap.)) Friday, October 11, 13
24. Implementing Interfaces Friday, October 11, 13
25. (.start (Thread. target)) Friday, October 11, 13
26. (reify Interface (method [this x y z] body)) Friday, October 11, 13
27. (reify InterfaceA (method-a [this x y z] body) InterfaceB (method-b [this m n] body)) Friday, October 11, 13
28. (.start (Thread. target)) Friday, October 11, 13
29. (let [target (fn [] ...) thread (Thread. target)] (.start thread)) Friday, October 11, 13
30. (let [target (reify Runnable (run [this _] (println "hello"))) thread (Thread. target)] (.start thread)) Friday, October 11, 13
31. Miscellanea (if time allows) Friday, October 11, 13
32. (make-array (Integer/TYPE) 5) (aset (to-array [1 2 3]) 1 5) (into-array [1 2 3]) Friday, October 11, 13
33. Access Clojure in Java Friday, October 11, 13
34. Creating Class Friday, October 11, 13
35. (gen-class :name my.namespace.MyClass) (compile 'my.namespace) (my.namespace.MyClass.) Friday, October 11, 13
36. (gen-class :name com.example.Hello :methods [[hello [String] String]]) (defn -hello [arg] (str "Hello, " arg)) (.hello (com.example.Hello.) "Jan") Friday, October 11, 13
37. (gen-class :name com.example.Hello :prefix Hello :methods [[hello [String] String]]) (defn Hello-hello [arg] (str "Hello, " arg)) (.hello (com.example.Hello.) "Jan") Friday, October 11, 13
38. (gen-class :name com.example.Hello :init init :constructors {[String] []}) (defn -init [arg] (println "Hello, " arg)) (com.example.Hello. "Jan") Friday, October 11, 13
39. (import [clojure.lang Seqable]) Friday, October 11, 13
40. (gen-class :name com.example.Hello :init init :state state :constructors {[Seqable] []}) (defn -init [seq] [nil seq]) (com.example.Hello. [:a :b :c]) Friday, October 11, 13
41. (gen-class :name com.example.Hello :init init :state state :constructors {[Seqable] []}) (defn -init [seq] [nil seq]) (com.example.Hello. [:a :b :c]) (defn -toString [this] (str (.state this))) Friday, October 11, 13
42. (gen-class :name com.example.Hello :implements [java.io.Serializable]) Friday, October 11, 13
43. (ns org.example.namespace (:gen-class)) (defn -main [arg] (println (.toUpperCase arg))) (compile 'org.example.namespace) java org.example.namespace hello! Friday, October 11, 13