返回具有通用输入的嵌套对象(return nested object with generic input)

 我有以下对象初始化。 它是RestfulService类的一部分。 
 
ParameterizedTypeReference<RestResponsePage<ScheduledScanDto>> ptr =
            new ParameterizedTypeReference<RestResponsePage<ScheduledScanDto>>(){};
 
 它在课堂上使用了好几次但有不同的参数。 例如 
 
ParameterizedTypeReference<RestResponsePage<ScanDto>> ptr =
            new ParameterizedTypeReference<RestResponsePage<ScanDto>>(){};
 
 要么 
 
ParameterizedTypeReference<RestResponsePage<SomeOtherObject>> ptr =
            new ParameterizedTypeReference<RestResponsePage<SomeOtherObject>>(){};
 
 它有点罗嗦......我试图创建一个私有方法来返回ParameterizedTypeReference对象作为私有方法的一部分。 这将减少类中的样板代码和代码重复。我正在努力使用私有​​方法的语法，特别是泛型的嵌套。 
 
 想通过执行以下操作获取ParameterizedTypeReference对象的实例 
 
pageTypeReference(AnyClassObjectHere.class)
 
 给出一些背景信息。 我计划通过在发出休息请求时调用private方法来减少样板代码。 所以看起来像以下.. 
 
private List<ScanDto> methodMakeScanRequest{
  List<ScanDto> = restTemplate.exchange("/localhost/scans-url",HttpMethod.GET, pageTypeReference(ScanDto.class)).getBody()
}
 
 
 
 更新中... 
 
 
 我的尝试看起来像这样。 这种作品。 但是它现在只是映射到通用链表。 对象类型被忽略。 
 
 
private <T> ParameterizedTypeReference<RestResponsePage<T>> pageTypeReference(Class<T> clazz) {
    return new ParameterizedTypeReference<RestResponsePage<T>>(){};
}

I have the following object initialization. Its part of a RestfulService class.
 
ParameterizedTypeReference<RestResponsePage<ScheduledScanDto>> ptr =
            new ParameterizedTypeReference<RestResponsePage<ScheduledScanDto>>(){};
 
It is used several times in the class but with different params. e.g. 
 
ParameterizedTypeReference<RestResponsePage<ScanDto>> ptr =
            new ParameterizedTypeReference<RestResponsePage<ScanDto>>(){};
 
or
 
ParameterizedTypeReference<RestResponsePage<SomeOtherObject>> ptr =
            new ParameterizedTypeReference<RestResponsePage<SomeOtherObject>>(){};
 
Its a bit wordy... I am trying to create a private method to return the ParameterizedTypeReference object as part of a private method. This will reduce boilerplate code in the class and code duplication.. I'm struggling with the syntax on the private method, in particular the nesting of generics.
 
Would like to get an instance of ParameterizedTypeReference objects by doing the following
 
pageTypeReference(AnyClassObjectHere.class)
 
To give some context. I plan to reduce boilerplate code by calling the private method when making a rest request. So would look like the following.. 
 
private List<ScanDto> methodMakeScanRequest{
  List<ScanDto> = restTemplate.exchange("/localhost/scans-url",HttpMethod.GET, pageTypeReference(ScanDto.class)).getBody()
}
 
 
 
Update...
 
 
My attempt looks like this. This kind of works. However it now just maps to a generic linkedlist. The object type is ignored.
 
 
private <T> ParameterizedTypeReference<RestResponsePage<T>> pageTypeReference(Class<T> clazz) {
    return new ParameterizedTypeReference<RestResponsePage<T>>(){};
}

原文：https://stackoverflow.com/questions/45213604