Spring纯注解开发

1. 必须要有一个配置类
2. 其余创建和注入值的方法之前一样
   详细参考代码：https://blog.csdn.net/qq_42923605/article/details/116950291?spm=1001.2014.3001.5501
3. 实例化的时候有所变化
   ClassPathConfigApplicationContext 变为了 AnnotationConfigApplicationContext

package com.xzh.Spring5.AllAnnotation;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

/**
 * @Author XuZhuHong
 * @CreateTime 2021/5/18 19:17
 */
@Configuration//纯注解开发  这个必须要定义在配置类上  说明他是配置类
@ComponentScan(basePackages = {"com.xzh"})//开启扫描  类似于<context:component-scan base-package="com.xzh"/>
public class SpringConfig {
}

实例化：

package com.xzh.Spring5.AllAnnotation;

import com.xzh.Spring5.Annotation.UserService;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.lang.annotation.Annotation;

/**
 * @Author XuZhuHong
 * @CreateTime 2021/5/18 15:24
 */
public class TestSpring {
    @Test
    public void test1() {
        //其余方法均不变
        //实例化方法会有所改变  改变成了  AnnotationConfigApplicationContext   后面的SpringConfig.class 是配置类的类名
        AnnotationConfigApplicationContext annotationConfigApplicationContext =
                new AnnotationConfigApplicationContext(SpringConfig.class);
        UserService userService = annotationConfigApplicationContext.getBean("userService", UserService.class);
        System.out.println(userService);
        userService.show();
    }
}