java中的方法参考 [英] Method reference in java
问题描述
我正在探索java中的方法引用,并且好奇是否可以将以下内容转换为方法引用
I'm exploring method reference in java, and just curious if following can be converted to a method reference
List<Integer> list = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8);
list.forEach(item -> new SomeClass(item).someMethod(item));
我尝试了以下操作,但这不起作用
I tried the following, but that didn't work
list.forEach(SomeClass::new::someMethod);
推荐答案
无法解决问题的方法你提供。但是可以通过将 someMethod
方法定义为 static
来完成:
There is no way to resolve the issue in the way you provided. But it could be done by defining the someMethod
method as static
:
list.forEach(item -> SomeClass.someMethod(item));
list.forEach(SomeClass::someMethod);
语句 SomeClass :: new :: someMethod
不正确。
严格来说, SomeClass :: new
是指一段构造函数代码(如 Consumer
),当你需要一个对象来进行方法引用时,它不会返回一个新实例 SomeClassinstance :: someMethod
。
The statement SomeClass::new::someMethod
is incorrect.
Strictly speaking, SomeClass::new
refers to a piece of constructor code (like a Consumer
), it does not return a new instance while you need an object to make a method reference SomeClassinstance::someMethod
.
编辑:
我真的没有看到这种方法的任何优点:
I really don't see any advantages of the approach:
map(SomeClass::new).forEach(SomeClass::someMethod)
因为它会导致创建一部分无用的 SomeClass
具有 item
的实例也将不会被使用。
because it leads to creation a portion of useless SomeClass
instances with item
s that also will not be used.
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