如何创建javax.inject.Provider <MyObject> 使用Spring

Question

I am writing an app that uses Springboot / Java 8 in the web tier and runs a Java Application in a worker tier. The worker reads from a message queue. I have common service singletons that are used in both tiers. I would like to use the javax.inject.Provider pattern to inject local prototype beans into the common service instances rather than passing them throughout all the service methods. So I'm trying to figure out how to best create javax.inject.Provider<ServiceContextInfo> .

I tried this in the config file:

@Configuration
public class MyConfiguration {

    @Bean 
    ReportInfo ReportInfo() {
        return new ReportInfo();
    }

    @Bean(name = "serviceContextInfo")
    public ServiceContextInfo serviceProviderInfoBean() {
        ServiceContextInfo info = new ServiceContextInfo();
        info.setReportInfo(reportInfo());
        return info;
    }

    @Bean
    public ProviderCreatingFactoryBean providerCreatingFactoryBean() {
        ServiceContextInfo info = new ServiceContextInfo();
        info.setReportInfo(reportInfo());
        ProviderCreatingFactoryBean providerFactory = new ProviderCreatingFactoryBean();
        providerFactory.setTargetBeanName("serviceContextInfo");
        return providerFactory;
    }

Then in the message receiver of the worker this is called:

    ProviderCreatingFactoryBean providerFactoryBean = 
                        applicationContext.getBean(ProviderCreatingFactoryBean.class);
    Provider<Object> serviceContextInfo = providerFactoryBean.getObject();
    ((ServiceContextInfo)serviceContextInfo.get()).
            setDynamicData(webToWorkerMessage.getDynamicData());

Here is the abstractService class:

public class AbstractService {

     @Inject
     protected Provider<ServiceContextInfo> contextInfo;
}

Here is the ServiceContextInfo class:

@Data
@Scope("prototype")
@Component
public class ServiceContextInfo {

    private ReportInfo reportInfo;
    private String dynamicData;

}

I feel like I'm on the right track; but I'm just not making the correlation between the simple examples using XML, Java config, and how to best support the dynamic data requirement... The call to the factory bean in the message listener doesn't appear to be working. Also, I would rather not assign to Provider<Object> , but rather to Provider<ServiceContextInfo> .

On the web tier, I would also build the ServiceContextInfo objects so that the service classes perform the same for both tiers.

Assistance would be greatly appreciated! Thanks in advance...

Answer 1

I was able to get this to work after all. Still have to deal with the Provider<Object> issue in the worker tier. The web tier injects it typed as desired. The rest works nicely. It was not as difficult as I thought...