Dropdown value binding in Spring MVC

Question

I am new to Spring MVC. I am writing an app that uses Spring, Spring MVC and JPA/Hibernate I don\'t know how to make Spring MVC set a value coming from a dropdown into a mod

Answer 1

The trick as you have already noted is to register a custom converter which will convert the id from the drop down into a Custom instance.

You can write a custom converter this way:

public class IdToCustomerConverter implements Converter<String, Customer>{
    @Autowired CustomerRepository customerRepository;
    public Customer convert(String id) {
        return this.customerRepository.findOne(Long.valueOf(id));
    }
}

Now register this converter with Spring MVC:

<mvc:annotation-driven conversion-service="conversionService"/>

<bean id="conversionService"
    class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
    <property name="converters">
       <list>
          <bean class="IdToCustomerConverter"/>
       </list>
    </property>
</bean>