找不到 MessageBodyReader for media type=application/json
我写了一个JAX-RS服务器和客户端都使用泽西岛。我想将我的实体集合发送给客户端,我执行了以下步骤:
- 使实体扩展可序列化
- 编写了自定义提供程序并对其进行了扩展以支持集合
- 将实体和提供程序复制粘贴到客户端
我发出一个请求,客户端在服务器端成功处理它收到错误:
org.glassfish.jersey.message.internal.MessageBodyProviderNotFoundException: MessageBodyReader not found for media type=application/json, type=interface java.util.List, genericType=java.util.List<model.HotelsEntity>.
org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$TerminalReaderInterceptor.aroundReadFrom(ReaderInterceptorExecutor.java:225)
org.glassfish.jersey.message.internal.ReaderInterceptorExecutor.proceed(ReaderInterceptorExecutor.java:149)
org.glassfish.jersey.message.internal.MessageBodyFactory.readFrom(MessageBodyFactory.java:1124)
org.glassfish.jersey.message.internal.InboundMessageContext.readEntity(InboundMessageContext.java:853)
org.glassfish.jersey.message.internal.InboundMessageContext.readEntity(InboundMessageContext.java:812)
org.glassfish.jersey.client.ClientResponse.readEntity(ClientResponse.java:377)
org.glassfish.jersey.client.JerseyInvocation.translate(JerseyInvocation.java:813)
org.glassfish.jersey.client.JerseyInvocation.access$600(JerseyInvocation.java:90)
org.glassfish.jersey.client.JerseyInvocation$3.call(JerseyInvocation.java:693)
org.glassfish.jersey.internal.Errors.process(Errors.java:315)
org.glassfish.jersey.internal.Errors.process(Errors.java:297)
org.glassfish.jersey.internal.Errors.process(Errors.java:228)
org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:424)
org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:689)
org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:405)
org.glassfish.jersey.client.JerseyInvocation$Builder.get(JerseyInvocation.java:301)
service.HotelService.getHotels(HotelService.java:30)
actions.HotelAction.perform(HotelAction.java:42)
MainServlet.processResponse(MainServlet.java:33)
MainServlet.doPost(MainServlet.java:22)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
服务器:
@GET
@Produces(MediaType.APPLICATION_JSON)
public Response getHotelsList(@QueryParam("startDate") String startDate,
@QueryParam("endDate") String endDate) {
List<HotelsEntity> list = hotelService.getAll();
return ResponseFactory.response(Response.Status.OK, list);
}
客户:
GenericType<List<HotelsEntity>> genericType = new GenericType<List<HotelsEntity>>(){};
WebTarget target = client.target(preparePath());
List<HotelsEntity> hotels = target.request(MediaType.APPLICATION_JSON_TYPE).get(genericType);
供应商:
public class JsonProvider<T> implements MessageBodyReader<T>, MessageBodyWriter<T> {
@Override
public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return MediaType.APPLICATION_JSON.equals(mediaType.getType()) &&
MediaType.APPLICATION_JSON.equals(mediaType.getSubtype());
}
@Override
public T readFrom(Class<T> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream) throws IOException, WebApplicationException {
Gson gson = createGson();
Reader reader = new InputStreamReader(entityStream, Charset.forName(Constants.UTF_8));
return gson.fromJson(reader, genericType);
}
@Override
public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return MediaType.APPLICATION_JSON.equals(mediaType.getType()) &&
MediaType.APPLICATION_JSON.equals(mediaType.getSubtype());
}
@Override
public long getSize(T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return -1;
}
@Override
public void writeTo(T t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream) throws IOException, WebApplicationException {
Gson gson = createGson();
JsonElement element = gson.toJsonTree(entityStream);
Writer writer = null;
try {
writer = new OutputStreamWriter(entityStream, Charset.forName(Constants.UTF_8));
gson.toJson(element, writer);
} finally {
if (writer != null) {
writer.flush();
}
}
}
private Gson createGson() {
return new GsonBuilder().setPrettyPrinting().create();
}
}
@Provider
public class JsonCollection extends JsonProvider<Collection<? extends HospitalityEntity>> {}
@Entity
@Table(name = "hotels", schema = "", catalog = "mydb")
public class HotelsEntity implements HospitalityEntity{
private int idHotel;
private String name;
private String region;
private String description;
@Id
@Column(name = "id_hotel")
public int getIdHotel() {
return idHotel;
}
public void setIdHotel(int idHotel) {
this.idHotel = idHotel;
}
@Basic
@Column(name = "name")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Basic
@Column(name = "region")
public String getRegion() {
return region;
}
public void setRegion(String region) {
this.region = region;
}
@Basic
@Column(name = "description")
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
HotelsEntity that = (HotelsEntity) o;
if (idHotel != that.idHotel) return false;
if (description != null ? !description.equals(that.description) : that.description != null) return false;
if (name != null ? !name.equals(that.name) : that.name != null) return false;
if (region != null ? !region.equals(that.region) : that.region != null) return false;
return true;
}
@Override
public int hashCode() {
int result = idHotel;
result = 31 * result + (name != null ? name.hashCode() : 0);
result = 31 * result + (region != null ? region.hashCode() : 0);
result = 31 * result + (description != null ? description.hashCode() : 0);
return result;
}
}