1.CustomerImportSelector工具类：

/*** @description : 自动导入器* @author : wanYunBo* @date : 2021-09-02 20:46**/
package com.itheima.config.selector;import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ImportSelector;
import org.springframework.core.io.support.PropertiesLoaderUtils;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.core.type.filter.AspectJTypeFilter;
import org.springframework.core.type.filter.TypeFilter;import java.io.IOException;
import java.util.*;public class CustomerImportSelector implements ImportSelector {private String expression;public CustomerImportSelector(){try {//初始化时指定加载的properties文件名,就是你文件名Properties loadAllProperties = PropertiesLoaderUtils.loadAllProperties("import2.properties");//设定加载的属性名，就是类似Myclass=com.lzb.dao.UserDao,com.lzb.dao.PersonDao//****就对应key的值(className)expression = loadAllProperties.getProperty("className");} catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();}}@Overridepublic String[] selectImports(AnnotationMetadata importingClassMetadata) {//1.定义扫描包的名称String[] basePackages = null;//2.判断有@Import注解的类上是否有@ComponentScan注解if (importingClassMetadata.hasAnnotation(ComponentScan.class.getName())) {//3.取出@ComponentScan注解的属性Map<String, Object> annotationAttributes = importingClassMetadata.getAnnotationAttributes(ComponentScan.class.getName());//4.取出属性名称为basePackages属性的值basePackages = (String[]) annotationAttributes.get("basePackages");}//5.判断是否有此属性（如果没有ComponentScan注解则属性值为null，如果有ComponentScan注解，则basePackages默认为空数组）if (basePackages == null || basePackages.length == 0) {String basePackage = null;try {//6.取出包含@Import注解类的包名basePackage = Class.forName(importingClassMetadata.getClassName()).getPackage().getName();} catch (ClassNotFoundException e) {e.printStackTrace();}//7.存入数组中basePackages = new String[] {basePackage};}//8.创建类路径扫描器ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(false);//9.创建类型过滤器(此处使用切入点表达式类型过滤器)TypeFilter typeFilter = new AspectJTypeFilter(expression,this.getClass().getClassLoader());//10.给扫描器加入类型过滤器scanner.addIncludeFilter(typeFilter);//11.创建存放全限定类名的集合Set<String> classes = new HashSet<>();//12.填充集合数据for (String basePackage : basePackages) {scanner.findCandidateComponents(basePackage).forEach(beanDefinition -> classes.add(beanDefinition.getBeanClassName()));}//13.按照规则返回return classes.toArray(new String[classes.size()]);}}

2.import2.properties属性文件

• 表示className=com.itheima.dao.impl下的bean对象不需要用@Repository("")配置，自动导入
• 应用场景，接口实现类较多，可采用导入器自动注入

className=com.itheima.dao.impl.*

3.导入SpringConfig类中加载

@Import(CustomerImportSelector.class)//将分配置文件引进来
public class SpringConfig {
}

4.所需classpath依赖

<!--通配导入器 classpath依赖--><dependency><groupId> org.aspectj</groupId ><artifactId> aspectjweaver</artifactId ><version> 1.8.7</version ></dependency>