MATLAB: REST Web Service call via Java does not find message body reader (MIME octet-stream)

javajerseyrestwebservices

We have developed a Java client/server application using REST and Jersey for the wrapping/unwrapping of data to be sent between client and server. This works fine within Eclipse as well as for the exported Jar file. We are now trying to use our Java client classes within Matlab to connect to the application server. This produces an error message related to the reader of the message body:
Mar 11, 2013 5:28:37 PM com.sun.jersey.api.client.ClientResponse getEntity
SEVERE: A message body reader for Java class ch.specchio.types.User, and Java type class ch.specchio.types.User, and MIME media type application/octet-stream was not found
Mar 11, 2013 5:28:37 PM com.sun.jersey.api.client.ClientResponse getEntity
SEVERE: The registered message body readers compatible with the MIME media type are:
application/octet-stream ->
  com.sun.jersey.core.impl.provider.entity.ByteArrayProvider
  com.sun.jersey.core.impl.provider.entity.FileProvider
  com.sun.jersey.core.impl.provider.entity.InputStreamProvider
  com.sun.jersey.core.impl.provider.entity.DataSourceProvider
  com.sun.jersey.core.impl.provider.entity.RenderedImageProvider
*/* ->
  com.sun.jersey.core.impl.provider.entity.FormProvider
  com.sun.jersey.core.impl.provider.entity.MimeMultipartProvider
  com.sun.jersey.core.impl.provider.entity.StringProvider
  com.sun.jersey.core.impl.provider.entity.ByteArrayProvider
  com.sun.jersey.core.impl.provider.entity.FileProvider
  com.sun.jersey.core.impl.provider.entity.InputStreamProvider
  com.sun.jersey.core.impl.provider.entity.DataSourceProvider
  com.sun.jersey.core.impl.provider.entity.XMLJAXBElementProvider$General
  com.sun.jersey.core.impl.provider.entity.ReaderProvider
  com.sun.jersey.core.impl.provider.entity.DocumentProvider
  com.sun.jersey.core.impl.provider.entity.SourceProvider$StreamSourceReader
  com.sun.jersey.core.impl.provider.entity.SourceProvider$SAXSourceReader
  com.sun.jersey.core.impl.provider.entity.SourceProvider$DOMSourceReader
  com.sun.jersey.core.impl.provider.entity.XMLRootElementProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLListElementProvider$General
  com.sun.jersey.core.impl.provider.entity.XMLRootObjectProvider$General
  com.sun.jersey.core.impl.provider.entity.EntityHolderReader
com.sun.jersey.api.client.ClientHandlerException: A message body reader for Java class ch.specchio.types.User, and Java type class ch.specchio.types.User, and MIME media type application/octet-stream was not found
  at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:550)
  at com.sun.jersey.api.client.ClientResponse.getEntity(ClientResponse.java:506)
  at com.sun.jersey.api.client.WebResource.handle(WebResource.java:674)
  at com.sun.jersey.api.client.WebResource.access$200(WebResource.java:74)
  at com.sun.jersey.api.client.WebResource$Builder.get(WebResource.java:503)
  at ch.specchio.client.SPECCHIOWebClient.getObject(SPECCHIOWebClient.java:1616)
  at ch.specchio.client.SPECCHIOWebClient.connect(SPECCHIOWebClient.java:192)
  at ch.specchio.client.SPECCHIOClientFactory.connect(SPECCHIOClientFactory.java:90)
  at ch.specchio.gui.DatabaseConnectionDialog.actionPerformed(DatabaseConnectionDialog.java:117)
  at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
  at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
  at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
  at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
  at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
  at java.awt.Component.processMouseEvent(Component.java:6382)
  at javax.swing.JComponent.processMouseEvent(JComponent.java:3275)
  at java.awt.Component.processEvent(Component.java:6147)
  at java.awt.Container.processEvent(Container.java:2083)
  at java.awt.Component.dispatchEventImpl(Component.java:4744)
  at java.awt.Container.dispatchEventImpl(Container.java:2141)
  at java.awt.Component.dispatchEvent(Component.java:4572)
  at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4619)
  at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4280)
  at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4210)
  at java.awt.Container.dispatchEventImpl(Container.java:2127)
  at java.awt.Window.dispatchEventImpl(Window.java:2489)
  at java.awt.Component.dispatchEvent(Component.java:4572)
  at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:704)
  at java.awt.EventQueue.access$400(EventQueue.java:82)
  at java.awt.EventQueue$2.run(EventQueue.java:663)
  at java.awt.EventQueue$2.run(EventQueue.java:661)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
  at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
  at java.awt.EventQueue$3.run(EventQueue.java:677)
  at java.awt.EventQueue$3.run(EventQueue.java:675)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:674)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
  at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
It appears that the returned message body is no longer XML but an octet stream and this is presumably preventing the proper unwrapping by Jersey. Why this happens is beyond me. The jar files and class paths are set within the classpath.txt file:
/Users/andyhueni/Documents/workspace/SPECCHIO Types/bin
/Users/andyhueni/Documents/workspace/SPECCHIO Web Client/bin
/Users/andyhueni/Documents/workspace/SPECCHIO Web Client/lib/jersey-client.jar
/Users/andyhueni/Documents/workspace/SPECCHIO Web Client/lib/jersey-core.jar
Within Java, the classes, such as in this case User, have been annotated with the return type, ditto the web service methods:
@XmlRootElement(name="user")
public class User {
....
}
  @GET
  @Produces(MediaType.APPLICATION_XML)
  @Path("login")
  public User login() throws SPECCHIOFactoryException {
    
    UserFactory factory = new UserFactory(getClientUsername(), getClientPassword());
    User user = factory.getUser(getClientUsername());
    factory.dispose();
    
    return user;
    
  }
Environment: – MATLAB R2011a – Eclipse Java EE, Juno Release 1 – Glassfish Server 3.1.2.2

Best Answer

Here is part 2 of the solution to the problem, which not strictly connected to Matlab, but also occurred when trying to call the services from R. You have to use the "copy required libraries into a sub-folder" option when exporting the JAR from Eclipse. The information that tipped us off to this solution is at: http://stackoverflow.com/questions/2730589/jersey-message-body-reader-not-found-in-maven-built-jar.
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