Clojure 支持Java

调用Java类

 

调用Constructor、Method、Field

(new classname)

 

(new java.util.Random)

    java.util.Random@4f1ada

 

(def rnd (new java.util.Random))

  #'user/rnd

 

(. class-or-instance member-symbol & args)

(. class-or-instance (member-symbol & args))

(. rnd nextInt)

    -791474443

(. rnd nextInt 10)

    8

(import [& import-lists])

; import-list => (package-symbol & class-name-symbols)

(import '(java.util Random Locale)

'(java.text MessageFormat))

    nil

Syntactic Sugar

(new Random)

==

(Random.)

最终结果相同，语法方式不同

(Classname/membername);static field or method

(. Math PI)

 Math/PI

(System/currentTimeMillis)

    1226260030788

(. rnd nextInt)

==

(.nextInt rnd)

想同，语法方式不同

(doto class-or-inst & member-access-forms)

(doto (System/getProperties)

(.setProperty "name" "Stuart")

(.setProperty "favoriteColor" "blue"))

Java	Clojure	Sugared
new Widget("red")	(new Widget "red")	(Widget. "red")
Math.PI	(. Math PI)	Math/PI
System.currentTimeMillis()	(. System currentTimeMillis	(System/currentTimeMillis)
rnd.nextInt()	(. rnd nextInt)	(.nextInt rnd)
person.getAddress().getZipCode()	(. (. person getAddress) getZipCode)	(.. person getAddress getZipCode)