将Clojure数据结构转换为Java集合

What is the Clojure-idiomatic way to convert a data structure to a Java collection, specifically:

什么是将数据结构转换为Java集合的Clojure-idiomatic方法，具体为：

[] to a java.util.ArrayList
[]到java.util.ArrayList
{} to a java.util.HashMap
{}到java.util.HashMap
#{} to a java.util.HashSet
#j}到java.util.HashSet
() to a java.util.LinkedList
（）到java.util.LinkedList

Is there a clojure.contrib library to do this?

是否有clojure.contrib库来执行此操作？

USE CASE: In order to ease Clojure into my organization, I am considering writing a unit-test suite for an all-Java REST server in Clojure. I have written part of the suite in Scala, but think that Clojure may be better because the macro support will reduce a lot of the boilerplate code (I need to test dozens of similar REST service calls).

使用案例：为了使Clojure易于进入我的组织，我正在考虑为Clojure中的全Java REST服务器编写单元测试套件。我已经在Scala中编写了部分套件，但认为Clojure可能更好，因为宏支持将减少很多样板代码（我需要测试几十个类似的REST服务调用）。

I am using EasyMock to mock the database connections (is there a better way?) and my mocked methods need to return java.util.List<java.util.Map<String, Object>> items (representing database row sets) to callers. I would pass in a [{ "first_name" "Joe" "last_name" "Smith" "date_of_birth" (date "1960-06-13") ... } ...] structure to my mock and convert it to the required Java collection so that it can be returned to the caller in the expected format.

我使用EasyMock来模拟数据库连接（有更好的方法吗？），我的模拟方法需要将java.util.List >项（代表数据库行集）返回给调用者。我会将[{“first_name”“Joe”“last_name”“Smith”“date_of_birth”（日期“1960-06-13”）...} ...]结构传递给我的模拟并将其转换为必需的Java集合，以便它可以以预期的格式返回给调用者。

1 个解决方案

#1

Clojure vector, set and list classes implement the java.util.Collection interface and ArrayList, HashSet and LinkedList can take a java.util.Collection constructor argument. So you can simply do:

Clojure向量，集合和列表类实现java.util.Collection接口和ArrayList，HashSet和LinkedList可以采用java.util.Collection构造函数参数。所以你可以简单地做：

user=> (java.util.ArrayList. [1 2 3])
#<ArrayList [1, 2, 3]>
user=> (.get (java.util.ArrayList. [1 2 3]) 0)
1

Similarly, Clojure map class implements java.util.Map interface and HashMap takes a java.util.Map constructor argument. So:

同样，Clojure map类实现java.util.Map接口，HashMap接受java.util.Map构造函数参数。所以：

user=> (java.util.HashMap. {"a" 1 "b" 2})
#<HashMap {b=2, a=1}>
user=> (.get (java.util.HashMap. {"a" 1 "b" 2}) "a")
1

You can also do the reverse and it is much easier:

您也可以反过来做起来更容易：

ser=> (into [] (java.util.ArrayList. [1 2 3]))
[1 2 3]
user=> (into #{} (java.util.HashSet. #{1 2 3}))
#{1 2 3}
user=> (into '() (java.util.LinkedList. '(1 2 3)))
(3 2 1)
user=> (into {} (java.util.HashMap. {:a 1 :b 2}))
{:b 2, :a 1}

#1