How to map with dozer a data type to different data type?

Question

I have a User and UserDTO class but in dto class i dont want to user LocalDateTime, i want to convert it to long type. (because protobuf not support date). So in code:

My User entity class:

public class User {
    private String name,password;
    private LocalDateTime date;
//getters-setters, tostring..
}

My DTO:

public class UserDTO {
    private String name,password;
    private long date;
//getters-setters, tostring..
}

And you see that the date in entity User is LocalDateTime, and in DTO is long. I want to use this dozermapper:

    UserDTO destObject =
            mapper.map(user, UserDTO.class);

The LocalDateTime changing code to long:

private static long setDateToLong(LocalDateTime date) {        
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
    String dateString = date.format(formatter);
    return Long.parseLong(dateString);        
}

Is it possible that the mapper knows that change the LocalDateTime to long? Can i somehow configure it? Thanks for the helps!

Answer 1

Finally i found a sollution which is create from LocalDateTime to String and back from String to LocalDateTime. I have to create a converter:

public class DozerConverter implements CustomConverter {
    @Override
    public Object convert(Object destination, Object source, Class destClass, Class sourceClass) {
        DateTimeFormatter formatter = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
        if(source instanceof String) {
            String sourceTime = (String) source;
            return LocalDateTime.parse(sourceTime, formatter);
        } else if (source instanceof LocalDateTime) {
            LocalDateTime sourceTime = (LocalDateTime) source;
            return sourceTime.toString();
        }
        return null;
    }

}

And in my custom xml i have to add the custom-converter attribute like this one:

<?xml version="1.0" encoding="UTF-8"?>
<mappings xmlns="http://dozer.sourceforge.net" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://dozer.sourceforge.net
      http://dozer.sourceforge.net/schema/beanmapping.xsd">
    <mapping>
        <class-a>mypackage.UserDTO</class-a>
        <class-b>mypackage.User</class-b>
        <field custom-converter="mypackage.DozerConverter">
            <a>lastLoggedInTime</a>
            <b>lastLoggedInTime</b>
        </field>
    </mapping>
</mappings>

I think it can work with any data types, just have to write more converter, or write this converter smart.