spring NamedContextFactory实现服务隔离的示例详解

public interface SmsService {

    void send(String phone, String content);
}

public class DefaultSmsService implements SmsService {
    @Override
    public void send(String phone, String content) {
        System.out.printf("send to %s content %s used default sms%n", phone, content);
    }
}

public class AliyunSmsService implements SmsService {
    @Override
    public void send(String phone, String content) {
        System.out.printf("send to %s content %s used aliyun sms%n", phone, content);
    }
}

public class HuaWeiSmsService implements SmsService {
    @Override
    public void send(String phone, String content) {
        System.out.printf("send to %s content %s used huawei sms%n", phone, content);
    }
}

@Configuration
public class DefaultSmsClientConfiguration {


    @Bean
    @ConditionalOnMissingBean
    public SmsService smsService(){
        return new DefaultSmsService();
    }

}

public class SmsClientSpecification implements NamedContextFactory.Specification{
    private String name;

    private Class<?>[] configuration;

    public SmsClientSpecification() {
    }

    public SmsClientSpecification(String name, Class<?>[] configuration) {
        this.name = name;
        this.configuration = configuration;
    }

    @Override
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public Class<?>[] getConfiguration() {
        return configuration;
    }

    public void setConfiguration(Class<?>[] configuration) {
        this.configuration = configuration;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        SmsClientSpecification that = (SmsClientSpecification) o;
        return Arrays.equals(configuration, that.configuration)
                && Objects.equals(name, that.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(configuration, name);
    }

    @Override
    public String toString() {
        return new StringBuilder("SmsSpecification{").append("name='")
                .append(name).append("', ").append("configuration=")
                .append(Arrays.toString(configuration)).append("}").toString();
    }
}

@Configuration
@Import(SmsClientConfigurationRegistrar.class)
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SmsClient {

    /**
     * Synonym for name (the name of the client).
     *
     * @see #name()
     * @return name of the Sms client
     */
    String value() default "";

    /**
     * The name of the sms client, uniquely identifying a set of client resources,
     * @return name of the Sms client
     */
    String name() default "";

    /**
     * A custom <code>@Configuration</code> for the sms client. Can contain override
     * <code>@Bean</code> definition for the pieces that make up the client
     */
    Class<?>[] configuration() default {};
}

@Configuration
@Retention(RetentionPolicy.RUNTIME)
@Target({ ElementType.TYPE })
@Documented
@Import(SmsClientConfigurationRegistrar.class)
public @interface SmsClients {

	SmsClient[] value() default {};

	Class<?>[] defaultConfiguration() default {};

}

public class SmsClientConfigurationRegistrar implements ImportBeanDefinitionRegistrar {

	@Override
	public void registerBeanDefinitions(AnnotationMetadata metadata,
			BeanDefinitionRegistry registry) {
		Map<String, Object> attrs = metadata
				.getAnnotationAttributes(SmsClients.class.getName(), true);
		if (attrs != null && attrs.containsKey("value")) {
			AnnotationAttributes[] clients = (AnnotationAttributes[]) attrs.get("value");
			for (AnnotationAttributes client : clients) {
				registerClientConfiguration(registry, getClientName(client),
						client.get("configuration"));
			}
		}
		if (attrs != null && attrs.containsKey("defaultConfiguration")) {
			String name;
			if (metadata.hasEnclosingClass()) {
				name = "default." + metadata.getEnclosingClassName();
			}
			else {
				name = "default." + metadata.getClassName();
			}
			registerClientConfiguration(registry, name,
					attrs.get("defaultConfiguration"));
		}
		Map<String, Object> client = metadata
				.getAnnotationAttributes(SmsClient.class.getName(), true);
		String name = getClientName(client);
		if (name != null) {
			registerClientConfiguration(registry, name, client.get("configuration"));
		}
	}

	private String getClientName(Map<String, Object> client) {
		if (client == null) {
			return null;
		}
		String value = (String) client.get("value");
		if (!StringUtils.hasText(value)) {
			value = (String) client.get("name");
		}
		if (StringUtils.hasText(value)) {
			return value;
		}
		throw new IllegalStateException(
				"Either 'name' or 'value' must be provided in @SmsClient");
	}

	private void registerClientConfiguration(BeanDefinitionRegistry registry, Object name,
			Object configuration) {
		BeanDefinitionBuilder builder = BeanDefinitionBuilder
				.genericBeanDefinition(SmsClientSpecification.class);
		builder.addConstructorArgValue(name);
		builder.addConstructorArgValue(configuration);
		registry.registerBeanDefinition(name + ".SmsClientSpecification",
				builder.getBeanDefinition());
	}

}

public class SmsClientNameContextFactory extends NamedContextFactory<SmsClientSpecification> {

    public SmsClientNameContextFactory() {
        super(DefaultSmsClientConfiguration.class, "sms", "sms.client.name");
    }

    public SmsService getSmsService(String serviceName) {
        return getInstance(serviceName, SmsService.class);
    }
}

public NamedContextFactory(Class<?> defaultConfigType, String propertySourceName,
			String propertyName) {
		this.defaultConfigType = defaultConfigType;
		this.propertySourceName = propertySourceName;
		this.propertyName = propertyName;
	}

   @Bean
    @ConditionalOnMissingBean
    public SmsClientNameContextFactory smsClientNameContextFactory(@Autowired(required = false) List<SmsClientSpecification> smsSpecifications){
        SmsClientNameContextFactory smsClientNameContextFactory = new SmsClientNameContextFactory();
        smsClientNameContextFactory.setConfigurations(smsSpecifications);
        return smsClientNameContextFactory;
    }

public class AliyunSmsClientConfiguration {

    @ConditionalOnMissingBean
    @Bean
    public SmsService smsService() {
       return new AliyunSmsService();
    }
}

public class HuaWeiSmsClientConfiguration {

    @ConditionalOnMissingBean
    @Bean
    public SmsService smsService() {
       return new HuaWeiSmsService();
    }
}

@Configuration
@SmsClients(value = {@SmsClient(name = OrderService.SERVICE_NAME, configuration = AliyunSmsClientConfiguration.class),
        @SmsClient(name = UserService.SERVICE_NAME, configuration = HuaWeiSmsClientConfiguration.class)})
public class SmsClientAutoConfiguration {
}

@Service
@RequiredArgsConstructor
public class UserService {

    private final ApplicationContext applicationContext;

    public static final String SERVICE_NAME = "userService";

    public void registerUser(String userName, String password,String mobile){
        System.out.println("注册用户"+userName+"成功");
        UserRegisterEvent event = new UserRegisterEvent(userName,password,mobile);
        applicationContext.publishEvent(event);
    }
}

@Component
@RequiredArgsConstructor
public class UserRegisterListener {

    private final SmsClientNameContextFactory smsClientNameContextFactory;


    @EventListener
    @Async
    public void listener(UserRegisterEvent event) {
        SmsService smsService = smsClientNameContextFactory.getSmsService(UserService.SERVICE_NAME);
        smsService.send(event.getMobile(), "恭喜您注册成功！初始密码为："+event.getPassword()+"，请尽快修改密码！");
    }
}

 SmsService smsService = smsClientNameContextFactory.getSmsService(UserService.SERVICE_NAME);