在非泛型类中实现泛型接口

Question

public interface Lookup<T>{
  public T find(String name);
}

public class IntegerLookup implements Lookup<Integer>{
  private Integer[] values;
  private String[] names;

  public IntegerLookup(String[] names, Integer[] values) {......}
  //now I want to write the implemented method - find

public Object find(String name){...}

会很好？或：

public Integer find(String name){...}

Answer 1

这里的语法

public class IntegerLookup implements Lookup<Integer>{
//                                           ^

绑定提供的类型参数，即。integer，转换为由lookup声明的类型变量，即。t。

所以，

public Integer find(String name){...}

Lookup<Integer> lookup = ...;
lookup.find("something"); // has a return type of Integer