对于编码器,我具有以下接口(interface),该编码将Object
编码为DataNode
对象并返回:
public interface DataMarshaller<T> {
/**
* returns the actual class that this marshaller is capable of marshalling.
* @return
*/
Class<T> getDataClass();
/**
* marshalls the object to a DataNode
*
* @param object
* @return
*/
DataNode marshal(T object);
/**
* unmarshalls the object from a DataNode
*
* @param node
* @return
*/
T unMarshal(DataNode node);
}
为了确保能够为对象获取正确的编码器,我还具有
Class<T> getDataClass()
方法来返回其类(由于类型擦除,该类在编译后会丢失)。现在,我想在一个能够编码(marshal)
Octree<T>
类型的对象的类中实现此接口(interface),如下所示:public class OctreeMarshaller<T> implements DataMarshaller<Octree<T>> {
@Override
public Class<Octree<T>> getDataClass() {
return Octree.class; //<- compiletime error
}
@Override
public DataNode marshal(Octree<T> object) {
//...
}
@Override
public Octree<T> unMarshal(DataNode node) {
//...
}
}
我的问题是,(当然)
Octree.class
不是Class<Octree<T>>
类型,而是非通用类型Class<Octree>
,而Java不允许我将其强制转换为Class<Octree<T>>
。现在的问题是:有没有比我已经考虑过的两种方法更优雅的解决方法:
Class<T>
更改为Class<?>
OctreeMarshaller
的类签名更改为public class OctreeMarshaller implements DataMarshaller<Octree>
最佳答案
没有Octree<T>
实例,就不能构造Class<Octree<T>>
类型的类对象。但是由于我们知道(由于类型擦除),在运行时只有一个类Octree
,因此可以安全地编写
public class OctreeMarshaller<T> implements DataMarshaller<Octree<T>> {
@Override
@SuppressWarnings("unchecked")
public Class<Octree<T>> getDataClass() {
return (Class<Octree<T>>)(Class<?>)Octree.class;
}
[...]
}