Spring ConversionService adding Converters

Question

I searched for the below problem, but couldn\'t find an answer.

I want to use spring\'s conversion service by writing my custom converter that implements org.spri

Answer 1

To resolve any circular dependencies, here the steps I followed (Spring Boot v5.2.1):

Register a simple conversionService

@Configuration
public class ConverterProvider {

    @Bean
    public ConversionService conversionService() {
        ConversionService conversionService = new GenericConversionService();
        return conversionService;
    }
}

Inject your custom converters

@Component
public class ConvertersInjection {

    @Autowired
    private GenericConversionService conversionService;

    @Autowired
    private void converters(Set<Converter> converters) {
        converters.forEach(conversionService::addConverter);
    }
}

The converter can even autowire your conversionService

@Component
public class PushNotificationConverter implements Converter<PushNotificationMessages.PushNotification, GCM> {
    @Lazy
    @Autowired
    private ConversionService conversionService;

    @Override
    public GCM convert(PushNotificationMessages.PushNotification source) {
        GCM gcm = new GCM();
        if (source.hasContent()) {
            PushNotificationMessages.PushNotification.Content content = source.getContent();
            if (content.hasData()) {
                conversionService.convert(content.getData(), gcm.getData().getClass());
            } else if (content.hasNotification()) {
                conversionService.convert(content.getNotification(), gcm.getNotification().getClass());
            }
        }
        return gcm;
    }
}

Answer 2

Came across a very interesting way to do this in Stackoverflow - https://stackoverflow.com/a/12760579/204788

Using a feature called Collection merging, you can essentially do this:

<bean id="customConversionService" class="org.springframework.context.support.ConversionServiceFactoryBean" parent="conversionService">
    <property name="converters">
        <list merge="true">
            <bean id="StringToLoggerConverter" class="com.citi.spring.converter.LoggerConverter" />
       </list>
   </property>
</bean>

Answer 3

write a custom conversionService

public class CustomerConversionServiceFactoryBean extends ConversionServiceFactoryBean {

    List<Converter<Object, Object>> converters = new ArrayList<>();

    public CustomerConversionServiceFactoryBean() {
        super();

    DefaultConversionService conversionservice = (DefaultConversionService)  super.getObject();

        for(int i=0;i<converters.size();i++){
            conversionservice.addConverter(converters.get(i));
        }
    }
}

then change your xml

<bean id="conversionService"
    class="CustomerConversionServiceFactoryBean" >
    <property name="converters" >
        <list>
            <bean class="CustomConverter"  />
        </list>
    </property>
</bean>

I think this will help you...