clojure - 如何在 clojure 中实例化 Stream.Builder 类？ (使用java 9)

Question

我按照此示例启动 Stream.Builder:

http://www.java2s.com/Tutorials/Java/java.util.stream/Stream.Builder/Stream.Builder.build_.htm

(def b (doto (Stream/builder)
          (.accept "a")
          (.accept "b")
          (.accept "c")
          (.accept "d")
          (.accept "e")))

但是，我得到了这个:

Unhandled java.lang.IncompatibleClassChangeError
 Method
 java.util.stream.Stream.builder()Ljava/util/stream/Stream$Builder;
 must be InterfaceMethodref constant

我有什么遗漏的吗？

Answer 1

快速研究让我发现了这个问题: https://dev.clojure.org/jira/browse/CLJ-2284

因此解决方法如下所述:

(import 'java.util.stream.Stream)

(defmacro interface-static-call
  [sym & argtypes]
  `(let [m# (.getMethod ~(symbol (namespace sym))
                        ~(name sym)
                        (into-array Class ~argtypes))]
     (fn [& args#]
       (.invoke m# nil (to-array args#)))))

(doto ((interface-static-call Stream/builder))
  (.accept "a")
  (.accept "b")
  (.accept "c")
  (.accept "d")
  (.accept "e"))

;;=> #object[java.util.stream.Streams$StreamBuilderImpl 0x121300ed "java.util.stream.Streams$StreamBuilderImpl@121300ed"]

在 java 9 上对我有用

所以我想我们应该等待 clojure 的修复。