User defined types with JsonMarshaller

I came across the JsonMarshaller project while searching for a Java library for unmarshalling JSON. This is a nifty little framework and uses Java 5 annotations for marshalling and unmarshalling JSON.

JsonMarshaller provides simple annotations @Entity and @Value for marking up your classes for marshalling and unmarshalling. However, I wanted something more than what the base framework provides - the ability to convert dates back and forth. The framework supports a so called type option to specify a user defined type for a value. This is a cool idea for extending the basic types supported out of the box. The (simplified) code for my DateType class that solved my problem is below:

public class DateType implements Type {

  @Override
  public Class getReturnedClass() {
      return Date.class;
  }

  @Override
  public Object marshall(Date entity) {
      SimpleDateFormat format = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z");
      return format.format(entity);
  }

  @Override
  public Date unmarshall(Object object) {
      String date = (String) object;
      Date d = null;
      try {
          d = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z").parse(date);
      } catch (ParseException e) {
          e.printStackTrace();
      }
      return d;
  }
}

This simple class can read a String representing a date in most commonly used formats and return a java.util.Date. It can also read a java.util.Date and return a String representing that date.