通用阵列创建错误 [英] Generic array creation error

问题描述

我试图做这样的事情： -

I am trying do something like this:-

public static ArrayList<myObject>[] a = new ArrayList<myObject>[2];

myObject的是一类。我收到此错误： - 通用阵列的创建（箭头指向新的。）

myObject is a class. I am getting this error:- Generic array creation (arrow is pointing to new.)

推荐答案

您不能有泛型类的数组。 Java的根本不支持它。

You can't have arrays of generic classes. Java simply doesn't support it.

您应该考虑使用一个集合，而不是一个数组。例如，

You should consider using a collection instead of an array. For instance,

public static ArrayList<List<MyObject>> a = new ArrayList<List<MyObject>();

另一个变通方法是创造这样一个辅助类

Another "workaround" is to create an auxilliary class like this

class MyObjectArrayList extends ArrayList<MyObject> { }

，然后创建 MyObjectArrayList 的数组。

下面是为什么这是不是在允许一个好文章语言。文章给出是否被允许的会发生什么，下面的例子：

Here is a good article on why this is not allowed in the language. The article gives the following example of what could happen if it was allowed:

List<String>[] lsa = new List<String>[10]; // illegal
Object[] oa = lsa;  // OK because List<String> is a subtype of Object
List<Integer> li = new ArrayList<Integer>();
li.add(new Integer(3));
oa[0] = li; 
String s = lsa[0].get(0); 

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