投例外,我有这样的方法:爪哇 - 可比
private SortedMap<String, SpaceObjectImpl> catalog = new TreeMap<String, SpaceObjectImpl>();
public Collection<SpaceObject> getSpaceObjects(){
SortedSet<SpaceObject> temp = new TreeSet<SpaceObject>(catalog.values());
return temp;
}
的compareTo同时这里定义:
public int compareTo(SpaceObjectImpl s){
....
}
class SpaceObjectImpl implements SpaceObject
当我运行程序,ClassCastException
被抛出。任何想法为什么?
错误:
SpaceObjectImpl cannot be cast to java.lang.Comparable(in TreeMap)
你需要有SpaceObjectImpl实现媲美。 – assylias
啊多数民众赞成它,谢谢.. :) –