Java Stream - 如何创建转换器功能接口

public class Main {
  public static void main(String... args) {
    Converter<String, Integer> integerConverter1 = (from) -> Integer.valueOf(from);
    Integer converted1 = integerConverter1.convert("123");
    System.out.println(converted1);   // result: 123

  }
}

@FunctionalInterface
interface Converter<F, T> {
    T convert(F from);
}