Plug-In mechanism missing for mapping from java.util.Date to Json

[leolux]

As stated in the javadoc of the interface Json.Factory the method make(Object) allows me to plug-in my own mapping of java.util.Date to Json. But how to achive this without reimplementing the whole method?

Futhermore I would like to know if it is possible to globally map the other way around from a Json string to java.util.Date. I would have expected something like Json.asDate() or Json.asType(Class type) for the conversion to Java instances.

[leolux]

To answer my first question: The plug-in mechansim can be used by overriding the method make(Object) instead of writing a new factory. For example:

public class MyJsonFactory extends Json.DefaultFactor
@Override
 public Json make(Object anything) {
    if(anything instanceof Date){
      String dateFormatAsString = ISO_DATETIME_FORMAT.format((Date)anything);
      return string(dateFormatAsString);
    }
    return super.make(anything);
  }

But I haven't found a solution for my second question (mapping from json to java).

[bolerio]

There is no general mapping between Json to an arbitrary Java object. This problem is external to JSON. I've been ruminating on doing an generic Java<->Json mapper as an extension, a separate project, but I haven't really seen much need for that.

[leolux]

Ok, thanks! I totally agree with you. The result of mapping from Json to Java does not need to be the same type of Java object used to create a Json value because the set of possible java classes is much larger than the finite set of Json values.

However the plug-in mechanism available to customize the Java<->Json mapping works nicely. I haven't found any other Json library which is as compact and neat as this one.