Implementing polymorphic Java interfaces with specific types

Question

I want to implement the Map<K,V> interface, but I want to constrain K to type String .

Is this possible? Or does the interface definition impose that K be polymorphic?

If it is possible, could someone help with the class signature, tks.

Answer 1

尝试： class Test< V > implements Map< String, V >希望对您有所帮助

Answer 2

No problem:

public class YourMap implements Map<String, Object> { /* ... */ }

If the class should be generic you can do:

public class YourMap<K extends String,V> implements Map<K, V> { /* ... */ }

But since String is final (as @Peter Lawrey commented), you might as well just do:

public class YourMap<V> implements Map<String, V> { /* ... */ }