让我们的Java示例:
public class Test {
public Test a;
public Test getA() {
return this.a;
}
public Test add(Test a) {
this.a = a;
return this;
}
public int foo(int a, int b, int c) {
return a+b+c;
}
public long foovar(Long... ai) {
long r = 0;
for (long i:ai) r+= i;
return r;
}
}
,并显示出一堆的方式访问内部对象:
(import 'Test)
;; create all the objects
(def t1 (Test.))
(def t2 (Test.))
(def t3 (Test.))
(def t4 (Test.))
(def t5 (Test.))
(def t6 (Test.))
;; and lets chain them together:
(.add t1 (.add t2 (.add t3 (.add t4 (.add t5 t6)))))
;; verify using member access:
(= t6 (.. t1 a a a a a)) ;; true
;; verify using method call:
(= t6 (.. t1 getA getA getA getA getA)) ;; true
;; and mixed access
(= t6 (.. t1 a a getA a a)) ;; true
;; lets invoke foo:
(.. t1 getA getA getA getA getA (foo 1 2 3)) ;; 6
;; and invoke foovar:
(.. t1 getA getA getA getA getA (foovar (into-array[1 2 3]))) ;; 6
现在,我们还可以创建辅助功能:
;; get the object at depth n using functions
(defn get-nth-function [o n]
(first (drop n (iterate (memfn getA) o))))
;; get the object at depth n using member access.
;; This same notation could also be used for function,
;; however I just wanted to show an example of memfn
(defn get-nth-member [o n]
(first (drop n (iterate #(.a %) o))))
;; lets verify:
(= t6 (get-nth-member t1 5)) ;; true
;; lets invoke foovar on object position 6,
;; on a range of numbers from 1 to 10
(.foovar (get-nth t1 5) (into-array (range 10))) ;; 45
这应该显示clojure和java之间交互的灵活性。当你有静态成员时,你可以像System/out
那样通过/
来访问它们(尽管.
也可以)。请务必完整阅读http://clojure-doc.org/articles/language/interop.html,如果您还没有收到任何东西,请告诉我们。
你有具体的例子吗?上面的示例有点含糊。举个例子,你可以先看http://clojuredocs.org/clojure.core/doto。另请参阅http://clojure-doc.org/articles/language/interop.html –
“链中的一些对象可能是静态类”[编号](http://stackoverflow.com/q/1215881/ 5044950) –
@AlanThompson实际上,['..'](https://clojuredocs.org/clojure.core/_ ..)在这种情况下更合适。 –