How to map collections in Dozer

Question

I\'d like to do something like:

ArrayList objects = new ArrayList();
...
DozerBeanMapper MAPPER = new DozerBeanMapper         


        

Answer 1

For that use case I once wrote a little helper class:

import java.util.Collection;

/**
 * Helper class for wrapping top level collections in dozer mappings.
 * 
 * @author Michael Ebert
 * @param 
 */
public final class TopLevelCollectionWrapper {

    private final Collection collection;

    /**
     * Private constructor. Create new instances via {@link #of(Collection)}.
     * 
     * @see {@link #of(Collection)}
     * @param collection
     */
    private TopLevelCollectionWrapper(final Collection collection) {
        this.collection = collection;
    }

    /**
     * @return the wrapped collection
     */
    public Collection getCollection() {
        return collection;
    }

    /**
     * Create new instance of {@link TopLevelCollectionWrapper}.
     * 
     * @param 
     *            Generic type of {@link Collection} element.
     * @param collection
     *            {@link Collection}
     * @return {@link TopLevelCollectionWrapper}
     */
    public static  TopLevelCollectionWrapper of(final Collection collection) {
        return new TopLevelCollectionWrapper(collection);
    }
}

You then would call dozer in the following manner:

private Mapper mapper;

@SuppressWarnings("unchecked")
public Collection getMappedCollection(final Collection collection) {
    TopLevelCollectionWrapper wrapper = mapper.map(
            TopLevelCollectionWrapper.of(collection),
            TopLevelCollectionWrapper.class);

    return wrapper.getCollection();
}

Only drawback: You get a "unchecked" warning on mapper.map(...) because of Dozers Mapper interface not handling generic types.