经营性商务网站建设需要备案吗,wordpress 如何编辑器,wordpress 去掉分类,网页页面下载Spring 是包含众多工具的 IoC 容器,存的是对象,对象这个词在 Spring 的范围内,称之为 bean IoC 是控制反转 控制权进行了反转,比如对某一个东西的控制权在 A 手上,结果变成了 B ,Spring 管理的是 bean ,所以这里的控制权指的是 bean 的控制权,也就是对象的控制权进行了反转 …Spring 是包含众多工具的 IoC 容器,存的是对象,对象这个词在 Spring 的范围内,称之为 bean IoC 是控制反转 控制权进行了反转,比如对某一个东西的控制权在 A 手上,结果变成了 B ,Spring 管理的是 bean ,所以这里的控制权指的是 bean 的控制权,也就是对象的控制权进行了反转 之前我们依赖的一些对象,我们需要自己去创建,通过 new 来进行创建,有了 Spring 之后我们就不再进行创建了,而是由 Spring 帮助我们进行创建,这就叫控制反转 控制反转的一个优点主要是解耦 耦合度高就说明两个事务的关联性密切,我们项目开发软件设计的原则是高内聚,低耦合 高内聚 : 是指一个模块内部的关系(比如一个班级) 低耦合 : 是指各个模块之间的关系(比如各个班级) 高内聚低耦合就是,一个班级内需要团结协作,但是各个班级之间的相互影响要小,一个班级的问题对别的班级的影响要降低 Spring MVC 和 Spring Boot 都属于 Spring ,Spring MVC 是基于 Spring 的一个 MVC 框架 ,而 Spring Boot 是基于 Spring 的一套快速开发整合包 IoC 是思想, DI(依赖注入) 是是一种实现方式 IoC 就是依赖的象的创建的控制权交给了 Spring 进行管理(存对象), DI 就是如何将依赖对象取出来,并赋给该对象的属性(取对象) IoC 提供了两类注解 :  1.类注解 : Controller(控制器存储) , Service(服务存储) , Repository(仓库存储) , Component(组件存储) , Configuration(配置存储) 2.方法注解 : Bean 接下来我们使用一下这些注解 ①  Controller 先创建一个 controller 包,在里面创建一个 UserController 类,用 Controller 告诉 Spring 帮我们管理这个对象 package com.example.ioc.controller;import org.springframework.stereotype.Controller;//用 Controller 告诉 Spring 帮我们管理这个对象 Controller public class UserController {public void doController(){System.out.println(do Controller...);} } 然后在启动类 DemoApplication 中查看 Spring 有没有把上面这个 Controller 存进来呢 package com.example.ioc; import com.example.ioc.controller.UserController; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();}} 运行出来了,说明存进去了 bean 一般使用这三个方法 ②  Service package com.example.ioc.service;import org.springframework.stereotype.Service;Service public class UserService {public void doService(){System.out.println(do service....);} }依旧在启动类 DemoApplication 中查看 package com.example.ioc;import com.example.ioc.controller.UserController; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();}} 成功拿到  根据名称来获取 UserService 的 bean (名称为类名转换为小驼峰,特殊情况就是如果类名前两位都是大写,那么bean的名称就是类名) package com.example.ioc;import com.example.ioc.controller.UserController; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();//根据名称来获取beanUserService userService1 (UserService) context.getBean(userService);userService1.doService();} 根据名称类型来拿 bean package com.example.ioc;import com.example.ioc.controller.UserController; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();//根据名称来获取beanUserService userService1 (UserService) context.getBean(userService);userService1.doService();//根据名称和类型来获取 beanUserService userService2 context.getBean(userService,UserService.class);userService2.doService();}③  Repository package com.example.ioc.repo;import org.springframework.stereotype.Repository;Repository public class UserRepository {public void doRepository(){System.out.println(do repo...);} } package com.example.ioc;import com.example.ioc.controller.UserController; import com.example.ioc.repo.UserRepository; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();//根据名称来获取beanUserService userService1 (UserService) context.getBean(userService);userService1.doService();//根据名称和类型来获取 beanUserService userService2 context.getBean(userService,UserService.class);userService2.doService();UserRepository userRepository context.getBean(UserRepository.class);userRepository.doRepository();} ④  Component package com.example.ioc.component;import org.springframework.stereotype.Component;Component public class UserComponent {public void doComponent(){System.out.println(do component);} } package com.example.ioc;import com.example.ioc.component.UserComponent; import com.example.ioc.controller.UserController; import com.example.ioc.repo.UserRepository; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();//根据名称来获取beanUserService userService1 (UserService) context.getBean(userService);userService1.doService();//根据名称和类型来获取 beanUserService userService2 context.getBean(userService,UserService.class);userService2.doService();UserRepository userRepository context.getBean(UserRepository.class);userRepository.doRepository();UserComponent userComponent context.getBean(UserComponent.class);userComponent.doComponent();}}⑤  Configuration package com.example.ioc.config;import org.springframework.context.annotation.Configuration;Configuration public class UserConfig {public void doConfig(){System.out.println(do configurarion...);} } package com.example.ioc;import com.example.ioc.component.UserComponent; import com.example.ioc.config.UserConfig; import com.example.ioc.controller.UserController; import com.example.ioc.repo.UserRepository; import com.example.ioc.service.UserService; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.ApplicationContext;SpringBootApplication public class DemoApplication {public static void main(String[] args) {//Spring 上下文ApplicationContext context SpringApplication.run(DemoApplication.class, args);//返回的就是 Spring 的运行环境UserController bean context.getBean(UserController.class);bean.doController();UserService userService context.getBean(UserService.class);userService.doService();//根据名称来获取beanUserService userService1 (UserService) context.getBean(userService);userService1.doService();//根据名称和类型来获取 beanUserService userService2 context.getBean(userService,UserService.class);userService2.doService();UserRepository userRepository context.getBean(UserRepository.class);userRepository.doRepository();UserComponent userComponent context.getBean(UserComponent.class);userComponent.doComponent();UserConfig userConfig context.getBean(UserConfig.class);userConfig.doConfig();}}