Looks like this is a bug #
http://java.net/jira/browse/JERSEY-632
I get the same error for any of MediaType.
com.sun.jersey.api.client.ClientHandlerException: A message body writer
for Java type, class com.sun.jersey.multipart.BodyPart, and MIME media
type, text/plain, was not found
com.sun.jersey.api.client.RequestWriter.writeRequestEntity(RequestWrite
r.java:299)
com.sun.jersey.client.urlconnection.URLConnectionClientHandler._invoke(
URLConnectionClientHandler.java:181)
com.sun.jersey.client.urlconnection.URLConnectionClientHandler.handle(U
RLConnectionClientHandler.java:129)
com.sun.jersey.api.client.Client.handle(Client.java:629)
com.sun.jersey.api.client.WebResource.handle(WebResource.java:601)
com.sun.jersey.api.client.WebResource.access$200(WebResource.java:74)
com.sun.jersey.api.client.WebResource$Builder.post(WebResource.java:507
)