这篇文章主要介绍了怎么使用spring中@ComponentScan自动扫描并指定扫描规则的相关知识，内容详细易懂，操作简单快捷，具有一定借鉴价值，相信大家阅读完这篇怎么使用spring中@ComponentScan自动扫描并指定扫描规则文章都会有所收获，下面我们一起来看看吧。
1.使用注解配置包扫描
1.1.创建相关类
分别创建BookDao、BookService、BookServiceImpl以及BookController这三个类，并在这三个类中分别添加@Repository、@Service、@Controller注解
BookDao
package com.tianxia.springannotation.dao;
import org.springframework.stereotype.Repository;
/**
* BookDao
* @author liqb
* @date 2023-04-21 16:37
**/
// 名字默认是类名首字母小写
@Repository
public class BookDao {
}BookService
package com.tianxia.springannotation.service;
/**
* BookService
* @author liqb
* @date 2023-04-21 16:38
**/
public interface BookService {
}BookServiceImpl
package com.tianxia.springannotation.service.impl;
import com.tianxia.springannotation.service.BookService;
import org.springframework.stereotype.Service;
/**
* BookServiceImpl
* @author liqb
* @date 2023-04-21 16:38
**/
@Service
public class BookServiceImpl implements BookService {
}BookController
package com.tianxia.springannotation.controller;
import org.springframework.stereotype.Controller;
/**
* BookController
* @author liqb
* @date 2023-04-21 16:39
**/
@Controller
public class BookController {
}1.2.SpringBoot启动类默认就有配置@ComponentScan
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
@SpringBootConfiguration
@EnableAutoConfiguration
@ComponentScan(excludeFilters = { @Filter(type = FilterType.CUSTOM, classes = TypeExcludeFilter.class),
@Filter(type = FilterType.CUSTOM, classes = AutoConfigurationExcludeFilter.class) })
public @interface SpringBootApplication {
}1.3.查看IOC中的bean的名称
package com.tianxia.springannotation;
import com.tianxia.springannotation.config.MainConfig;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
/**
* ComponentScanTest
* @author liqb
* @date 2023-04-21 16:45
**/
@SpringBootTest
@RunWith(SpringJUnit4ClassRunner.class)
public class ComponentScanTest {
/**
* 查看IOC容器中有哪些bean
* @author liqb
* @date 2023-04-21 16:45
*/
@Test
public void test() {
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(SpringAnnotationApplication.class);
// 我们现在就来看一下IOC容器中有哪些bean，即容器中所有bean定义的名字
String[] definitionNames = applicationContext.getBeanDefinitionNames();
for (String name : definitionNames) {
System.out.println(name);
}
}
}2.扫描时排除注解标注的类
在注解类上通过@ComponentScan注解的excludeFilters()方法
package com.tianxia.springannotation;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;
/**
* 启动类
* @author liqb
* @date 2023-04-21 16:12
**/
@SpringBootApplication
// value指定要扫描的包
@ComponentScan(value="com.tianxia.springannotation", excludeFilters={
/*
* type：指定你要排除的规则，是按照注解进行排除，还是按照给定的类型进行排除，还是按照正则表达式进行排除，等等
* classes：除了@Controller和@Service标注的组件之外，IOC容器中剩下的组件我都要，即相当于是我要排除@Controller和@Service这俩注解标注的组件。
*/
@ComponentScan.Filter(type= FilterType.ANNOTATION, classes={Controller.class, Service.class})
})
public class SpringAnnotationApplication {
public static void main(String[] args) {
SpringApplication.run(SpringAnnotationApplication.class, args);
}
}3.扫描时只包含注解标注的类
在注解类中的includeFilters()方法来指定Spring在进行包扫描时，只包含哪些注解标注的
这里需要注意的是，当我们使用includeFilters()方法来指定只包含哪些注解标注的类时，需要禁用掉默认的过滤规则
package com.tianxia.springannotation;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
/**
* 启动类
* @author liqb
* @date 2023-04-21 16:12
**/
@SpringBootApplication
// value指定要扫描的包
@ComponentScan(value="com.tianxia.springannotation", includeFilters={
/*
* type：指定你要排除的规则，是按照注解进行排除，还是按照给定的类型进行排除，还是按照正则表达式进行排除，等等
* classes：我们需要Spring在扫描时，只包含@Controller注解标注的类
*/
@ComponentScan.Filter(type=FilterType.ANNOTATION, classes={Controller.class})
}, useDefaultFilters=false)
public class SpringAnnotationApplication {
public static void main(String[] args) {
SpringApplication.run(SpringAnnotationApplication.class, args);
}
}4.重复注解
@ComponentScans({
@ComponentScan(value="com.tianxia.springannotation", includeFilters={
/*
* type：指定你要排除的规则，是按照注解进行排除，还是按照给定的类型进行排除，还是按照正则表达式进行排除，等等
* classes：我们需要Spring在扫描时，只包含@Controller注解标注的类
*/
@ComponentScan.Filter(type=FilterType.ANNOTATION, classes={Controller.class})
}, useDefaultFilters=false),
@ComponentScan(value="com.tianxia.springannotation", includeFilters={
/*
* type：指定你要排除的规则，是按照注解进行排除，还是按照给定的类型进行排除，还是按照正则表达式进行排除，等等
* classes：我们需要Spring在扫描时，只包含@Controller注解标注的类
*/
@ComponentScan.Filter(type=FilterType.ANNOTATION, classes={Service.class})
}, useDefaultFilters=false)
})