通过类< T>在通用列表的Java? [英] Passing the Class<T> in java of a generic list?
问题描述
我有一个从服务中读取JSON的方法,我使用Gson来完成我的序列化,并使用类型参数编写了以下方法。
public T getDeserializedJSON(Class< T> aClass,String url)
{
Reader r = getJSONDataAsReader(url);
Gson gson = new Gson();
返回gson.fromJson(r,aClass);
}
我正在使用json,它只返回一个类型的数组,例如 p>
[
{prop:value}
{prop:value}
$ b 我有一个映射到这个对象的java类,我们称之为MyClass。然而,要使用我的方法,我需要这样做:
RestClient< ArrayList< MyClass>> restClient = new RestClient< ArrayList< MyClass>>();
ArrayList< MyClass> results = restClient.getDeserializedJSON(ArrayList< MyClass> .class,url);
但是,我无法弄清楚它的语法。传递只是ArrayList.class不起作用。
那么有什么方法可以摆脱Class参数,或者如何获取MyClass的ArrayList类?
解决方案您可以使用Bozho的解决方案,或者避免使用以下代码创建临时数组列表:
类< List< MyClass>> clazz =(Class)List.class;
这个解决方案唯一的问题是你必须用@SuppressWarnings(unchecked )。
I have a method for reading JSON from a service, I'm using Gson to do my serialization and have written the following method using type parameters.
public T getDeserializedJSON(Class<T> aClass,String url)
{
Reader r = getJSONDataAsReader(url);
Gson gson = new Gson();
return gson.fromJson(r, aClass);
}
I'm consuming json which returns just an array of a type e.g.
[
{ "prop":"value" }
{ "prop":"value" }
]
I have a java class which maps to this object let's call it MyClass. However to use my method I need to do this:
RestClient<ArrayList<MyClass>> restClient = new RestClient<ArrayList<MyClass>>();
ArrayList<MyClass> results = restClient.getDeserializedJSON(ArrayList<MyClass>.class, url);
However, I can't figure out the syntax to do it. Passing just ArrayList.class doesn't work.
So is there a way I can get rid of the Class parameter or how do I get the class of the ArrayList of MyClass?
解决方案 You can use Bozho's solution, or avoid the creation of a temporary array list by using:
Class<List<MyClass>> clazz = (Class) List.class;
The only problem with this solution is that you have to suppress the unchecked warning with @SuppressWarnings("unchecked").
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