net.markenwerk.commons.interfaces

Interface Translator<From,To>

Type Parameters:

From - The type to translate values from and to.

To - The type to translate values to and from.

All Superinterfaces:

Converter<From,To>

public interface Translator<From,To>
extends Converter<From,To>

A Translator is used to convert (transform, translate, project, evaluate, ...) values from one form into another and back.

Common use cases of a Converter include:

• Translation from a simple type into a more complex type and back.
  

   Converter<String, UUID> uuidTranslator = new Translator<String, UUID> () {
      @Override
     public UUID convert(String uuidString) throws ConverterException {
       try{
         return UUID.fromString(uuidString);
       } catch (IllegalArgumentException e) {
         throw new ConverterException(e);
       }
     }
      
      @Override
     public String revert(UUID uuid) {
       return uuid.toString();
     }
   };
   

• Projection of a complex type to one of it's key components and back.
  

   Converter<Entity, Integer> idConverter = new Converter<Entity, Integer> () {
      @Override
     public Integer convert(Entity entity) throws ConverterException {
       return entity.getId();
     }
     
      @Override
     public Entity revert(Integer id) {
       try{
         return EntityDao.getById(id);
       } catch (EntityDaoException e) {
         throw new ConverterException(e);
       }
     }
   };
   

Since:

1.0.0

Author:

Torsten Krause (tk at markenwerk dot net)

Method Summary

Modifier and Type	Method and Description
From	revert(To to) Called to revert a given value.

Methods inherited from interface net.markenwerk.commons.interfaces.Converter

convert

Method Detail

revert

From revert(To to)
     throws ConversionException

Called to revert a given value. This is the reverse function of Converter.convert(Object).

Implementers should catch any exception and wrap them in a ConversionException.

Depending on the use case, if the given value null, the Translator should return null.

It lies in the responsibility of the caller, to handle unwanted null-values by replacing them with a sensible default value or throwing a NullPointerException.

Parameters:

to - The value to be reverted.

Returns:

The reverted value.

Throws:

ConversionException - If the reversion failed.