java - How to register custom converters in spring boot?

Question

I writing application using spring-boot-starter-jdbc (v1.3.0).

The problem that I met: Instance of BeanPropertyRowMapper fails as it cannot convert from java.sql.Timestamp to java.time.LocalDateTime.

In order to copy this problem, I implemented org.springframework.core.convert.converter.Converter for these types.

public class TimeStampToLocalDateTimeConverter implements Converter<Timestamp, LocalDateTime> {

    @Override
    public LocalDateTime convert(Timestamp s) {
        return s.toLocalDateTime();
    }
}

My question is: How do I make available TimeStampToLocalDateTimeConverter for BeanPropertyRowMapper.

More general question, how do I register my converters, in order to make them available system wide?

The following code bring us to NullPointerException on initialization stage:

private Set<Converter> getConverters() {
    Set<Converter> converters = new HashSet<Converter>();
    converters.add(new TimeStampToLocalDateTimeConverter());
    converters.add(new LocalDateTimeToTimestampConverter());

    return converters;
}

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

Thank you.

Answer 1

All custom conversion service has to be registered with the FormatterRegistry. Try creating a new configuration and register the conversion service by implementing the WebMvcConfigurer

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addallFormatters(FormatterRegistry registry) {
        registry.addConverter(new TimeStampToLocalDateTimeConverter());
    }
}

Hope this works.