Mapping list to list in Dozer

Question

List<CustomerData> mapAddress(List<Address> addressList){

   List<Customer> customerData = new ArrayList<Customer>();

   if( CollectionUtils.isNotEmpty( addressList ) ){
        for( Address address : addressList )
        {
            customerData.add( this.dozerBeanMapper.map( address, Customer.class ) );
        }
   }
   return customerData;
}

CustomerData.java :

Has instance field 'address' of type String

Address.java

Has instance field 'mainLocation' of type String

Currently I am using for loop to map each object of Address with Customer, how can I directly map addressList with customerData (list to list) without looping. Can someone please help me with the xml file changes for this logic.

Answer 1

As far as I remember there was no possibility to map a Collection to a Collection in Dozer. You need to iterate over it. Take a look at this closed issue and the reason: https://github.com/DozerMapper/dozer/issues/5

What you could do to ease the pain would be using Java 8 (if you can) or Guava for some more declarative way of handling that mapping.

Java 8 example:

<FROM, TO> List<TO> mapList(List<FROM> fromList, final Class<TO> toClass) {
    return fromList
            .stream()
            .map(from -> this.dozerBeanMapper.map(from, toClass))
            .collect(Collectors.toList());
}

Guava example:

<FROM, TO> List<TO> mapList(List<FROM> fromList, final Class<TO> toClass) {
    return Lists.transform(fromList, new Function<FROM, TO>() {
        @Override
        public TO apply(FROM from) {
            return this.dozerBeanMapper(from, toClass);
        }
    });
}

Answer 2

Hi I think this could be useful, thanks @gmaslowski for the idea:

/**
 * @param <T>
 * @param <V>
 * @param fromList list source objects
 * @param toClass target class objects
 * @param mapperId map-id in to dozer-mapping file 
 * @return list of toClass mapped 
 */
public <T, V> List<V> mapList(List<T> fromList, Class<V> toClass, String mapperId) {
    return fromList.stream().map(from -> {
        try {
            return this.dozerBean.getObject().map(from, toClass, mapperId);
        } catch (Exception e) {
            log.error("Error Dozer Mapping Objects {}", e.getMessage());
        }
        return null;
    }).collect(Collectors.toList());
}