java - 类型无法创建 List 的通用数组

Question

假设我有 FooClass 类。

public class FooClass {
}

以下行给我以下编译错误:

// Note I want to create an array of length 4 of Lists of FooClass
List<FooClass> runs[]=new List<FooClass>[4];

Cannot create a generic array of List<FooClass> ...

非常感谢任何帮助。

Answer 1

List Collection 与array不一样:

// if you want create a List of FooClass (you can use any List implementation)
List<FooClass> runs = new ArrayList<FooClass>();

// if you want create array of FooClass
FooClass[] runs = new FooClass[4];

更新:

如果你想创建列表数组，你应该:

1. 创建数组
2. 用 List 实例填充这个数组

例子:

List<FooClass>[] runs = new List[4];
for (int i = 0; i < runs.length; i++) {
    runs[i] = new ArrayList<>();
}