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一.工程结构

1.1 工程结构

、

1.2 逻辑流程

1.先用注解@component将ApplicationContextUtils放到ioc容器中

2.在使用的类中进行引用。

二 操作案例

2.1 将application实例化放到ioc容器中

package com.ljf.spring.boot.demo.util;import org.springframework.beans.BeansException;import org.springframework.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;import org.springframework.stereotype.Component;/** * @ClassName: ApplicationContextUtils * @Description: TODO * @Author: liujianfu * @Date: 2020/11/03 21:14:43  * @Version: V1.0 **/@Component   //此注解记住一定要加，实例化这个bean放到spring的容器中public class ApplicationContextUtils implements ApplicationContextAware {    private static ApplicationContext context;    @Override    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {        System.out.println("..............application context 在初始化:..............");        this.context = applicationContext;        System.out.println("context:"+context);    }    //根据bean名字获取工厂中指定bean 对象    public static Object getBean(String beanName){        System.out.println("context:"+context);        return context.getBean(beanName);    }}

2.2 service层

package com.ljf.spring.boot.demo.service.impl;import com.ljf.spring.boot.demo.service.UserService;import org.springframework.stereotype.Service;import java.util.ArrayList;import java.util.List;/** * @ClassName: UserServiceImpl * @Description: TODO * @Author: liujianfu * @Date: 2021/05/31 11:13:53  * @Version: V1.0 **/@Service("userService")public class UserServiceImpl implements UserService {    @Override    public List
   
     queryUserList() {        List
    
      dataList=new ArrayList<>();        dataList.add("liu");        dataList.add("nou");        return dataList;    }}
    
   

2.3  controller

package com.ljf.spring.boot.demo.controller;import com.ljf.spring.boot.demo.service.UserService;import com.ljf.spring.boot.demo.util.ApplicationContextUtils;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.ApplicationContext;import org.springframework.stereotype.Component;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import java.util.List;/** * @ClassName: UserController * @Description: TODO * @Author: liujianfu * @Date: 2021/05/31 11:30:35  * @Version: V1.0 **/@Controllerpublic class UserController{    @Autowired    private ApplicationContextUtils applicationContext;    @RequestMapping("/test")    @ResponseBody    public Object show(){        UserService userService = (UserService) ApplicationContextUtils.getBean("userService");        List
   
     list= userService.queryUserList();        System.out.println("list:"+list.toString());        return "ok:"+list.toString();    }}
   

2.4 启动

package com.ljf.spring.boot.demo;import com.ljf.spring.boot.demo.service.UserService;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.context.ConfigurableApplicationContext;import sun.plugin2.message.CustomSecurityManagerRequestMessage;import java.util.List;/** * Hello world! * */@SpringBootApplicationpublic class App {    public static void main( String[] args )    {        SpringApplication.run(App.class);        /**        SpringApplication application = new SpringApplication(App.class);        ConfigurableApplicationContext context = application.run(args);        UserService userPoJpaRepository = context.getBean(UserService.class);        List
   
     list= userPoJpaRepository.queryUserList();        System.out.println("list:"+list.toString());         **/        System.out.println("启动完成！！！");    }}
   

2.5 测试

转载地址：http://fatgi.baihongyu.com/