前言

最近业务部门向咱们反馈一个问题，咱们部门原先提供的组件忽然用不了了。前面排查是因为咱们提供进来的组件类没有注入到spring 容器中，之前没问题是因为业务部门的根包名跟咱们组件的根包名是一样，后续他们根包名换了，导致咱们的组件类没法注入到spring中，过后的解决方案是形如下

@SpringBootApplication(scanBasePackages = {"业务根包","组件根包"})

就是在业务的启动类上加上扫描组件根包。

尽管这样的形式能够解决，然而预先复盘了一下，业务方是否须要理解组件根包？是否还有更优雅一点的形式？本文就来聊聊如何把第三方服务注册到咱们我的项目的spring容器中

注入形式

1、注入的组件个数比拟少

1、主动拆卸机制 + @Bean的模式

示例：

@Configuration@Slf4j@EnableConfigurationProperties(XxlJobProperty.class)public class XxlJobAutoConfiguration {    @Bean    @ConditionalOnMissingBean    public XxlJobSpringExecutor xxlJobExecutor(XxlJobProperty property) {        log.info(">>>>>>>>>>> xxl-job config init.");        XxlJobSpringExecutor xxlJobSpringExecutor = new XxlJobSpringExecutor();        xxlJobSpringExecutor.setAdminAddresses(property.getAdminAddresses());        xxlJobSpringExecutor.setAppname(property.getExecutorAppname());        xxlJobSpringExecutor.setAddress(property.getExecutorAddress());        xxlJobSpringExecutor.setIp(property.getExecutorIp());        xxlJobSpringExecutor.setPort(property.getExecutorPort());        xxlJobSpringExecutor.setAccessToken(property.getAccessToken());        xxlJobSpringExecutor.setLogPath(property.getExecutorLogPath());        xxlJobSpringExecutor.setLogRetentionDays(property.getExecutorLogRetentionDays());        return xxlJobSpringExecutor;    }

在META-INF/spring.factories退出

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\com.github.lybgeek.autoconfiure.XxlJobAutoConfiguration
2、利用@Eanblexxx + @Import机制

示例：

@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Import(HelloSeviceImpl.class)public @interface EnableHelloSvc{}

在业务我的项目启动加上@EnableHelloSvc

3、调用beanFactory.registerSingleton()

示例：

@Slf4jpublic class HelloSvcBeanFactoryPostProcessor implements BeanFactoryPostProcessor {    @Override    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {        String beanName = StringUtils.uncapitalize(HelloService.class.getSimpleName());        log.info("register bean : beanName:{}",beanName);        beanFactory.registerSingleton(beanName,new HelloServiceImpl());    }}

2、注入的组件个数比拟多

1、主动拆卸机制 + @ComponentScan

示例：

@Configuration@ComponentScan(basePackages = Constant.SVC_PACAKAEE)public class ThirdPartySvcAutoConfiguration {}

在META-INF/spring.factories退出

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\com.github.lybgeek.autoconfiure.ThirdPartySvcAutoConfiguration
2、@Eanblexxx + @Import机制+ClassPathScanningCandidateComponentProvider

示例：

public class ThirdPartySvcRegister implements ImportBeanDefinitionRegistrar {    @Override    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {        ClassPathBeanDefinitionScanner classPathBeanDefinitionScanner = new ClassPathBeanDefinitionScanner(registry);        classPathBeanDefinitionScanner.scan(Constant.SVC_PACAKAEE);    }}
@Target(ElementType.TYPE)@Retention(RetentionPolicy.RUNTIME)@Documented@Import(ThirdPartySvcRegister.class)public @interface EnableThirdPartySvc {}

在业务我的项目启动加上@EnableThirdPartySvc

总结

如果是业务开发人员间接应用

@SpringBootApplication(scanBasePackages = {"业务根包","组件根包"})

其实是没问题的，然而如果作为组件提供给其余业务部门应用，能让业务部门无感知，开箱即用会是比拟优雅的形式

demo链接

https://github.com/lyb-geek/springboot-learning/tree/master/springboot-scan-thirdparty-service