How to create an object with a combination of methods?

Question

I have a versatile custom object converter which should be able to,

• read from XML and write to XML
• read from XML and write to CSV
• read from CSV and write to XML
• read from CSV and write to CSV

So, I thought I could do smth like :

Converter
{
 IReader reader;
 IWriter writer;
}
IReader
{
 read();
}

..(same for writer) then instantiate a Converter from one of each, implementing interface:

new Converter(XMLReader, CSVWriter);

(where XMLReader implements IReader & CSVWriter implements IWriter)

But then again, it would be cooler to be able to keep the XML related classes together too.

Can be a simple question with a simple answer, but I was wondering if we could come up with a more elegant solution.

Thanks in advance

• fge: If you have defined classes for XML sources and CSV sources, why not a Converter<IN, OUT> interface which you'd implement for all cases?
• Orkun: that d make 4 classes tho, no? could you explain maybe a bit more?
• fge: Well, three actually since you can implement an IdentityConverter<T> as a Converter<T, T> ;) You do not really tell much about your reader/writer interfaces though, so it is difficult to come with a "perfect" solution

Answer 1

Your design is fine. If you want to group your classes together use packages. For example create packages: com.mycompany.xml and com.mycompany.csv. Then put CsvReader and CsvWriter to com.mycompany.csv and XmlReader and XmlWriter to com.mycompany.xml.