java – Jersey JAXB如何为List实现MessageBodyWriter

我正在尝试为List实现MessageBodyWriter.使用此实现,我有一个空指针异常在线; marshaller.marshal(o,entityStream);

@Provider
@Produces(MediaType.APPLICATION_XML) 
public class MyListProvider implements MessageBodyWriteraraTION,Boolean.TRUE);
             marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,Boolean.TRUE);
        } catch (JAXBException e) {
            System.err.println("/////////////"+e.getMessage());
            //e.printstacktrace();
        }

    }
    @Override
    public long getSize(ListarameterizedType)genericType).getActualTypeArguments()[0]).equals(Data.class);
    }

    @Override
    public void writeto(List%s\" standalone=\"yes\"?>",cName).getBytes(cName));

        entityStream.write(String.format("<%s>",myWrapElemName).getBytes(cName));

        for (Data o : list){
          try {
              marshaller.marshal(o,entityStream);
          } catch(JAXBException exp) {
             exp.printstacktrace();
              //System.exit(-1);
          }
        }

        entityStream.write(String.format("%s>",myWrapElemName).getBytes(cName));
    }


}

最佳答案

public void writeto(List%s\" standalone=\"yes\"?>",cName).getBytes(cName));

    entityStream.write(String.format("<%s>",myWrapElemName).getBytes(cName));
    InstrumentModelListProvider();
    for (Data o : list){
      try {
          marshaller.marshal(o,entityStream);
      } catch(JAXBException exp) {
         exp.printstacktrace();
          //System.exit(-1);
      }
    }

    entityStream.write(String.format("%s>",myWrapElemName).getBytes(cName));
}