Review the Comparator class; it has two abstract methods, why it can be a function interface? Comparator.java package java.util; @FunctionalInterface public interface Comparator<T> { // abstract method int compare(T o1, T o2); // abstract method boolean equals(Object obj); // few default and static methods } Definition of function interface Conceptually, a functional interface has exactly …
For self-reference, this article shows you how to create a Abstract class for Spring Controller, or a template method design pattern. 1. Abstract Controller In Abstract class, the @Controller annotation is optional, your implemented class will apply it. AbstractResultController.java package com.mkyong.web.controller; import java.util.Map; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.servlet.ModelAndView; …