How to configure Spring ConversionService with jav

问题:

I have such xml:

<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
        <property name="converters">
            <list>
                <bean class="converters.AddressToStringConverter" />
                <bean class="converters.StringToAddressConverter" />
            </list>
        </property>
    </bean>

It configures converters without problems.

But then this code fails to make the same:

@Configuration
public class ConversionConfiguration {

    @Bean
    public ConversionService getConversionService() {
        ConversionServiceFactoryBean bean = new ConversionServiceFactoryBean();
        bean.setConverters(getConverters());
        bean.afterPropertiesSet();
        ConversionService object = bean.getObject();
        return object;
    }

    private Set<Converter> getConverters() {
        Set<Converter> converters = new HashSet<Converter>();

        converters.add(new AddressToStringConverter());
        converters.add(new StringToAddressConverter());

        return converters;
    }
}

This piece of configuration gets scanned by context - I checked it with debugger. Where could be the problem?

回答1:

From my point of view your problem is the Bean name. Once you don't explicit set the name using @Bean(name="conversionService") the name that will be used is getConversionService.

From documentation:

The name of this bean, or if plural, aliases for this bean. If left unspecified the name of the bean is the name of the annotated method. If specified, the method name is ignored.

回答2:

In SpringMVC you can extend WebMvcConfigurerAdapter and use it for Java based config. To register custom converters you can modify the "addFormatters"-Method like this

@Configuration
@EnableWebMvc
@ComponentScan(basePackages = { "..." })
public class ApplicationConfiguration extends WebMvcConfigurerAdapter
{
    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer)
    {
        configurer.enable();
    }

    @Bean
    public InternalResourceViewResolver getInternalResourceViewResolver()
    {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        return resolver;
    }

    @Override
    public void addFormatters(FormatterRegistry formatterRegistry)
    {
        formatterRegistry.addConverter(getMyConverter());
    }

    @Bean
    public StringToCounterConverter getMyConverter()
    {
        return new StringToCounterConverter();
    }

}

回答3:

When you enable logging, you'll see which Beans are created by Spring, as described here.

Log configuration

    <logger name="org.springframework.beans" level="DEBUG" />

Log output

    DEBUG (AbstractAutowireCapableBeanFactory.java:458) - Finished creating instance of bean 'getConversionService'

I copy+pasted your code and it worked without changing the name. I injected the ConversionService as follows:

@Resource
private ConversionService conversionService;

This works because of Autowiring by type. So maybe you had two ConversionService beans.