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spring中@ComponentScan自动扫描并指定扫描规则

目录
  • 1.使用注解配置包扫描
    • 1.1.创建相关类
    • 1.2.SpringBoot启动类默认就有配置@ComponentScan
    • 1.3.查看IOC中的bean的名称
  • 2.扫描时排除注解标注的类
    • 3.扫描时只包含注解标注的类
      • 4.重复注解

        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.springannowww.devze.comtation.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
         **/
        @SpringBoot编程客栈Test
        @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);
                }
            }
        }

        spring中@ComponentScan自动扫描并指定扫描规则

        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);
            }
        }

        spring中@ComponentScan自动扫描并指定扫描规则

        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.SpringBootApplicat开发者_C培训ion;
        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javascript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
                 */
         javascript       @ComponentScan.Filter(TsVWsttype=FilterType.ANNOTATION, classes={Controller.class})
        }, useDefaultFilters=false)
        public class SpringAnnotationApplication {
            public static void main(String[] args) {
                SpringApplication.run(SpringAnnotationApplication.class, args);
            }
        }

        spring中@ComponentScan自动扫描并指定扫描规则

        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)
        })

        到此这篇关于spring中@ComponentScan自动扫描并指定扫描规则的文章就介绍到这了,更多相关spring @ComponentScan自动扫描内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们!

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