找不到媒体类型的 MessageBodyWriter=application/xml

MessageBodyWriter not found for media type=application/xml

我想根据请求的 HttpHeader 以两种格式进行 REST API 响应:

@Context
HttpHeaders headers; 

public Response toResponse(MyValidationException exception) {
   if(headers.getMediaType().toString().equals(MediaType.APPLICATION_XML)){
     return Response.status(Status.BAD_REQUEST).entity(exception.getErrors()).type(MediaType.APPLICATION_XML).build();
  }else{
     return Response.status(Status.BAD_REQUEST).entity(exception.getErrors()).type(MediaType.APPLICATION_JSON).build();
}}

它适用于 MediaType.APPLICATION_JSON,但对于 MediaType.APPLICATION_XML 我收到以下错误:

org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo MessageBodyWriter not found for media type=application/xml, type=class java.util.HashMap$EntrySet, genericType=class java.util.HashMap$EntrySet.

有解决这个问题的想法吗?

你的项目中有jaxb依赖吗?

<dependency>
  <groupId>org.glassfish.jersey.media</groupId>
  <artifactId>jersey-media-jaxb</artifactId>
  <version>x.x.x</version>
</dependency>

如果是,也许您可​​以尝试将 exception.getErrors()(这似乎是一个地图?)包装成一个 GenericEntity 并将该实体提供给响应:

GenericEntity<Map<?, ?>> entity = new GenericEntity..

return Response.status(Status.X).entity(entity).type(MediaType.APPLICATION_XML).build();

添加 GenericEntity<>,如 ialex 所述,解决了我的问题。这就是我所做的:

GenericEntity<List<?>> genericEntity = new GenericEntity<List<?>> (exception.getErrors()) {};
Response.status(Status.BAD_REQUEST).entity(genericEntity).build();