title: javax.servlet.ServletException: org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: org/xml/sax/helpers/DefaultHandler
body: <p>I am getting a show-stopping error trying to obtain JSON output from a basic JAX-RS setup. I am trying Netbeans' Web Services wizards which has generated this default 'service' code:</p>
  
  <pre><code>package service;
  
  import entities.Manufacturer;
  import java.util.List;
  import javax.ejb.Stateless;
  import javax.persistence.EntityManager;
  import javax.persistence.PersistenceContext;
  import javax.ws.rs.Consumes;
  import javax.ws.rs.DELETE;
  import javax.ws.rs.GET;
  import javax.ws.rs.POST;
  import javax.ws.rs.PUT;
  import javax.ws.rs.Path;
  import javax.ws.rs.PathParam;
  import javax.ws.rs.Produces;
  import javax.ws.rs.core.MediaType;
  
  
  @Stateless
  @Path("entities.manufacturer")
  public class ManufacturerFacadeREST extends AbstractFacade&lt;Manufacturer&gt; {
  
      @PersistenceContext(unitName = "RestDemoPU")
      private EntityManager em;
  
      public ManufacturerFacadeREST() {
          super(Manufacturer.class);
      }
  
      @POST
      @Override
      @Consumes({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
      public void create(Manufacturer entity) {
          super.create(entity);
      }
  
      @PUT
      @Path("{id}")
      @Consumes({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
      public void edit(@PathParam("id") Integer id, Manufacturer entity) {
          super.edit(entity);
      }
  
      @DELETE
      @Path("{id}")
      public void remove(@PathParam("id") Integer id) {
          super.remove(super.find(id));
      }
  
      @GET
      @Path("{id}")
      @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
      public Manufacturer find(@PathParam("id") Integer id) {
          return super.find(id);
      }
  
      @GET
      @Override
      @Produces({MediaType.APPLICATION_JSON})
      public List&lt;Manufacturer&gt; findAll() {
          return super.findAll();
      }
  
      @GET
      @Path("{from}/{to}")
      @Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
      public List&lt;Manufacturer&gt; findRange(@PathParam("from") Integer from, @PathParam("to") Integer to) {
          return super.findRange(new int[]{from, to});
      }
  
      @GET
      @Path("count")
      @Produces(MediaType.TEXT_PLAIN)
      public String countREST() {
          return String.valueOf(super.count());
      }
  
      @Override
      protected EntityManager getEntityManager() {
          return em;
      }
  
  }
  </code></pre>
  
  <p>The error is showing up when I remove the <code>@Produces</code> annotation for <code>MediaType.APPLICATION_XML</code> in the <code>findAll()</code> method to leave <code>MediaType.APPLICATION_JSON</code> (I only want JSON output).</p>
  
  <p>XML is fine - the JSON-only annotation raises a <code>HTTP Status 500 - Internal Server Error</code> with Java exception: <code>javax.servlet.ServletException: org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: org/xml/sax/helpers/DefaultHandler</code> error.</p>
  
  <p>Using GlassFish 4.1.1. Server log is:</p>
  
  <pre><code>Info:   EclipseLink, version: Eclipse Persistence Services - 2.6.1.v20150605-31e8258
  Info:   /file:/home/lemon/code/java/Netbeans/RestDemo/build/web/WEB-INF/classes/_RestDemoPU login successful
  Warning:   StandardWrapperValve[service.ApplicationConfig]: Servlet.service() for servlet service.ApplicationConfig threw exception
  java.lang.ClassNotFoundException: org.xml.sax.helpers.DefaultHandler not found by org.eclipse.persistence.moxy [6]
      at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1532)
      at org.apache.felix.framework.BundleWiringImpl.access$400(BundleWiringImpl.java:75)
      at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1955)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
      at org.eclipse.persistence.jaxb.BeanValidationHelper.&lt;clinit&gt;(BeanValidationHelper.java:53)
      at org.eclipse.persistence.jaxb.JAXBBeanValidator.isConstrainedObject(JAXBBeanValidator.java:257)
      at org.eclipse.persistence.jaxb.JAXBBeanValidator.shouldValidate(JAXBBeanValidator.java:208)
      at org.eclipse.persistence.jaxb.JAXBMarshaller.validateAndTransformIfNeeded(JAXBMarshaller.java:587)
      at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:481)
      at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:949)
      at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:265)
      at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:250)
      at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
      at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:106)
      at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
      at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:86)
      at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
      at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1130)
      at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:683)
      at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:424)
      at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:414)
      at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:312)
      at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
      at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
      at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
      at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
      at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
      at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
      at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:292)
      at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1139)
      at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:460)
      at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:386)
      at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:334)
      at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)
      at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
      at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
      at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
      at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
      at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
      at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
      at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
      at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
      at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
      at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
      at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
      at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
      at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
      at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
      at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
      at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
      at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
      at java.lang.Thread.run(Thread.java:745)
  </code></pre>