MediaTypeFromMessageBodyWriterListAsText.java

package org.jboss.resteasy.test.resource.basic.resource;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Collection;

import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;

@Provider
@Produces(MediaType.TEXT_PLAIN + "; charset=UTF-8")
public class MediaTypeFromMessageBodyWriterListAsText implements MessageBodyWriter<Iterable<?>> {

   @Override
   public long getSize(final Iterable<?> t, final Class<?> type, final Type genericType, final Annotation[] annotations,
         final MediaType mediaType) {
      return -1L;
   }

   @Override
   public boolean isWriteable(final Class<?> type, final Type genericType, final Annotation[] annotations,
         final MediaType mediaType) {
      return Iterable.class.isAssignableFrom(type);
   }

   @Override
   public void writeTo(final Iterable<?> items, final Class<?> type, final Type genericType,
         final Annotation[] annotations, final MediaType mediaType, final MultivaluedMap<String, Object> httpHeaders,
         final OutputStream out) throws IOException {

      if (items instanceof Collection) {
         httpHeaders.putSingle("X-COUNT", Integer.toString(((Collection<?>) items).size()));
      }
   }
}