不能解析为一个类型

I want to change the return type of this method to a class (ReturnContainer) that can hold the tupelo object in addition to another return value that I need to send back to the calling method.

我想将此方法的返回类型更改为一个类(ReturnContainer)，它可以保存tupelo对象，并将我需要返回的另一个返回值返回给调用方法。

I've never worked with this <T> concept in Java before so I don't how to reconfigure this method to work the way I need it to.

我以前从来没有在Java中使用过这个< t>概念，所以我不知道如何重新配置这个方法以达到我所需要的方式。

public static <T extends LocationCapable> List<T> test(Class<T> incomingClass)
{
    List<TestTuple<T>> tupelo = new ArrayList<TestTuple<T>>();
    return tupelo;
}

When I try to change the code to the listing below, I get the error:

当我尝试将代码更改为下面的列表时，我得到了错误:

T cannot be resolved to a type

How can I have a return type of ReturnContainer but still allow the incomingClass to be a dynamic type?

我如何有返回类型的ReturnContainer，但仍然允许incomingClass是动态类型?

public static ReturnContainer test(Class<T> incomingClass)
{
            List<TestTuple<T>> tupelo = new ArrayList<TestTuple<T>>();
            ReturnContainer rc = new ReturnContainer(tupelo, incomingClass);
    return rc;
}

1 个解决方案

#1

You're missing the type parameter:

您缺少类型参数:

public static <T> ReturnContainer test(Class<T> incomingClass)
{
    List<TestTuple<T>> tupelo = new ArrayList<TestTuple<T>>();
    ReturnContainer rc = new ReturnContainer(tupelo, incomingClass);
    return rc;
}

To my eyes, though, this looks weird. Shouldn't ReturnContainer have a type parameter, too? In which case, you'd have

但在我看来，这看起来很奇怪。ReturnContainer不应该也有类型参数吗?在这种情况下，你会

public static <T> ReturnContainer<T> test(Class<T> incomingClass)
{
    List<TestTuple<T>> tupelo = new ArrayList<TestTuple<T>>();
    ReturnContainer rc = new ReturnContainer<T>(tupelo, incomingClass);
    return rc;
}

#1