为什么没有的ArrayList（T [] T）构造函数？ [英] Why there is no ArrayList(T[] t) constructor?

问题描述

这是很常见通过以这种方式的对象数组初始化列表：

It is very common to initialize list by array of objects in such way:

Foo[] objs = ...;
ArrayList<Foo> list = new ArrayList<Foo>(Arrays.asList(objs));

我不知道，是没有任何理由的ArrayList desiners不包括数组作为参数的构造函数，这样就可以像初始化：

I wonder, is there any reason why desiners of ArrayList didn't include constructor with array as parameter, so that it could be initialized like that:

ArrayList<Foo> list = new ArrayList<Foo>(objs);

可能是它违反了一些原则，线程安全或者其他什么东西？

May be it violates some principles, thread-safety or something else?

推荐答案

我不知道为什么这不是标准库，但是的番石榴的<一个href=\"http://guava-libraries.google$c$c.com/svn/trunk/javadoc/com/google/common/collect/Lists.html\"><$c$c>Lists类有 newArrayList 甚至与类型推断帮助：

I don't know why it's not in the standard library, but Guava's Lists class has newArrayList which even helps with type inference:

ArrayList<Foo> list = Lists.newArrayList(objs);

（您可能要导入 Lists.newArrayList 静态，如果你经常使用它。）

(You may want to import Lists.newArrayList statically if you use it a lot.)

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