implementation of a MessageBodyReader<DataHandler>

DataHandlerReader.java

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.ws.rs.Consumes;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

/**
 * @author Ryan Heaton
 */
@Provider
@Consumes( MediaType.WILDCARD )
public class DataHandlerReader implements MessageBodyReader<DataHandler> {

  public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
    return DataHandler.class.isAssignableFrom(type);
  }

  public DataHandler readFrom(Class<DataHandler> type, Type genericType, Annotation[] annotations, final MediaType mediaType, MultivaluedMap<String, String> httpHeaders, final InputStream entityStream) throws IOException, WebApplicationException {
    return new DataHandler(new DataSource() {
      public InputStream getInputStream() throws IOException {
        return entityStream;
      }

      public OutputStream getOutputStream() throws IOException {
        throw new IOException();
      }

      public String getContentType() {
        return mediaType.toString();
      }

      public String getName() {
        return getClass().getName();
      }
    });
  }
  
}