将一个bean中的firstName，lastName映射为另一个bean中的名字

Question

I am trying to map two beans in Java using Dozer and have the following scenario:

CustomerA has firstName and lastName

public Class CustomerA {
    public String firstName;
    public String lastName;
    ...
    // Getters and Setters
}

CustomerB has name, which needs to be mapped to firstName+" "+lastName

public Class CustomerB {
    public String name;
    ...
    // Getters and Setters
}

Is it possible to achieve this using Dozer? How will the mapping file look like? I have a custom convertor as follows:

public class NameConvertor {
    public Object convert(Object destination, Object source, Class destClass, Class sourceClass) {
        Object retValue = null;
        if (source == null) {
            return null;
        }
        if (source instanceof CustomerA) {
            CustomerA src = (CustomerA) source;
            CustomerB dest = (CustomerB) destination;
            if (destination == null) {
                dest = new CustomerB();
            }
            dest.setName(src.getFirstName()+" "+src.getLastName());
            retValue = dest;
        } else if (source instanceof CustomerB) {
            CustomerB src = (CustomerB) source;
            CustomerA dest = (CustomerA) destination;
            if (destination == null) {
                dest = new CustomerA();
            }
            dest.setFirstName(src.getName().split(" ")[0]);
            dest.setLastName(src.getName().split(" ")[1]);
            retValue = dest;
        }
        return retValue;
    }
}

Answer 1

You could pass 'this' (your instance of A) into a custom converter, concatenate the two fields together and return them to be mapped to the destination.

So, in your mapping you would have something like this:

<mapping>
  <class-a>path.to.CustomerA</class-a>
  <class-b>path.to.CustomerB</class-b>
  <field custom-converter="NameConverter" type="one-way">
    <a>this</a>
    <b>name</b>
  </field>
</mapping>

Then in your converter you would have something like this:

CustomerA customerA = (CustomerA) source;
StringBuilder builder = new StringBuilder();
builder.append(customerA.getFirstName());
builder.append(customerA.getLastName());
return builder.toString();

I tested with some sample code and it mapped as expected. Let me know if it works for you!

Answer 2

How do I map multiple fields to a single field?

Dozer doesn't currently support this. And because of the complexities around implementing it, this feature is not currently on the road map. A possible solution would be to wrap the multiple fields in a custom complex type and then define a custom converter for mapping between the complex type and the single field. This way, you could handle the custom logic required to map the three fields into the single one within the custom converter.

Source: http://dozer.sourceforge.net/documentation/faq.html#mult-fields-to-single-field

Also I advice to look here http://www.tikalk.com/advanced-dozer-mappings/