無法使用Spring和JavaConfig創建服務

Question

我無法使用Spring和JavaConfig創建服務。

這是我的主要課程：

public class MainApp
{

    private static final Logger LOGGER = getLogger(MainApp.class);


    public static void main(String[] args)
    {
        ApplicationContext context = new AnnotationConfigApplicationContext(HelloWorldConfig.class);
        MessageService mService  = context.getBean(MessageService.class);

        HelloWorld helloWorld = context.getBean(HelloWorld.class);


        LOGGER.debug("Message from HelloWorld Bean: " + helloWorld.getMessage());

        Message message = new Message();
        message.setMessage(helloWorld.getMessage());
        mService.SaveMessage(message);



        helloWorld.setMessage("I am in Staten Island, New York");


        LOGGER.debug("Message from HelloWorld Bean: " + helloWorld.getMessage());
    }
}

這是我的配置

@Configuration
@ComponentScan(basePackages = {"com.xxxx.HelloSpringJavaBasedJavaConfig"})
@Import(DatabaseConfig.class)
@PropertySource("classpath:application.properties")
public class HelloWorldConfig
{

    @Autowired
    Environment env;

    @Bean
    public MessageService messageService() {
        return new MessageServiceImpl();
    }


    @Bean
    public HelloWorld getHelloWorld()
    {
        HelloWorld hw = new HelloWorld();

       /*
        This is use to read in the property from the application.properties file
       */

        hw.setMessage(env.getProperty("bean.text"));

        return hw;
    }


}

這是錯誤：

Exception in thread "main" org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [com.xxxx.HelloSpringJavaBasedJavaConfig.service.MessageService] is defined: expected single matching bean but found 2: messageServiceImpl,messageService

Answer 1

我敢打賭，您已經用@Service或類似的注釋了MessageServiceImpl 。 與類路徑掃描結合使用，這意味着將創建兩個MessageServiceImpl Bean，一次是通過掃描，一次是從messageService方法。 擺脫一個或另一個。