Say we have the function:
假设我们有这个功能:
<T> T getFromCache (ClassType<T> clazz);
For strings:
String str = getFromCache(String.class);
For maps what I am currently thinking of doing:
对于我目前正在考虑做的地图:
//…
Map<String, SomeData> anotherMapObject = getFromCache( HashMap.class);
Can we be more specific than this ?
我们可以比这更具体吗?
One solution ofcourse is to wrap ‘HashMap’ in one class. But if we don’t want to do that then is there a better solution ?
一个解决方案是将“HashMap”包装在一个类中。但如果我们不想这样做,那么有更好的解决方案吗?
1 个解决方案
#1
0
If you want the map implementation to be passed in you can do this:
如果您希望传递地图实现,则可以执行以下操作:
private <M extends Map> Map<String, String> get(Class<M> m) throws Exception {
return (Map<String, String>) m.newInstance();
}
You can parametrize the key and value types like this:
您可以像这样参数化键和值类型:
private <M extends Map<K, V>, K, V> M getMap(Class<M> m, Class<K> k, Class<V> v)
#1
0
If you want the map implementation to be passed in you can do this:
如果您希望传递地图实现,则可以执行以下操作:
private <M extends Map> Map<String, String> get(Class<M> m) throws Exception {
return (Map<String, String>) m.newInstance();
}
You can parametrize the key and value types like this:
您可以像这样参数化键和值类型:
private <M extends Map<K, V>, K, V> M getMap(Class<M> m, Class<K> k, Class<V> v)