ConfigurationClassPostProcessor 之 @ComponentScan

package com.github.mengweijin.mybatisplus.demo.ComponentScan.test;

import lombok.Data;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Component;

@Data
@Component
@ComponentScan(value = "com.github.mengweijin.mybatisplus.demo.ComponentScan.entity")
public class ComponentScanConfiguration {

}

package com.github.mengweijin.mybatisplus.demo.ComponentScan.entity;

import org.springframework.stereotype.Component;

@Component
public class ComponentScanEntity {
}

测试

虽然测试类扫描的是 ComponentScan.test 包下的所有类，并没有扫描 ComponentScan.entity 包。 但由于 ComponentScanConfiguration 类上添加了注解 @ComponentScan(value = "com.github.mengweijin.mybatisplus.demo.ComponentScan.entity")

因此，ComponentScan.entity 包下面的 ComponentScanEntity 也能够被 Spring 容器扫描到，这就是 @ComponentScan 的用法。

package com.github.mengweijin.mybatisplus.demo.ComponentScan.test;

import com.github.mengweijin.mybatisplus.demo.ComponentScan.entity.ComponentScanEntity;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

@Slf4j
public class TestComponentScan {

    @Test
    public void componentScan(){
        String basePackages = "com.github.mengweijin.mybatisplus.demo.ComponentScan.test";
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(basePackages);

        Assertions.assertNotNull(context.getBean(ComponentScanEntity.class));
        context.close();
    }
}