请看这里的例子，它最好地说明了这个问题，以及在Jersey的最新(2.3.1)版本中是如何解决的。

https://jersey.java.net/documentation/latest/representations.html#d0e3586

它基本上包括定义一个自定义Exception并将返回类型保留为实体。当出现错误时，抛出异常，否则，返回POJO。

如果您的WS-RS需求引发错误，为什么不直接使用WebApplicationException呢?

@GET
@Produces({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
@Path("{id}")
public MyEntity getFoo(@PathParam("id") long id,  @QueryParam("lang")long idLanguage) {

if (idLanguage== 0){
    // No URL parameter idLanguage was sent
    ResponseBuilder builder = Response.status(Response.Status.BAD_REQUEST);
    builder.entity("Missing idLanguage parameter on request");
    Response response = builder.build();
    throw new WebApplicationException(response);
    }
... //other stuff to return my entity
return myEntity;
}

我发现用重复的代码构建json消息非常有用，就像这样:

@POST
@Consumes("application/json")
@Produces("application/json")
public Response authUser(JsonObject authData) {
    String email = authData.getString("email");
    String password = authData.getString("password");
    JSONObject json = new JSONObject();
    if (email.equalsIgnoreCase(user.getEmail()) && password.equalsIgnoreCase(user.getPassword())) {
        json.put("status", "success");
        json.put("code", Response.Status.OK.getStatusCode());
        json.put("message", "User " + authData.getString("email") + " authenticated.");
        return Response.ok(json.toString()).build();
    } else {
        json.put("status", "error");
        json.put("code", Response.Status.NOT_FOUND.getStatusCode());
        json.put("message", "User " + authData.getString("email") + " not found.");
        return Response.status(Response.Status.NOT_FOUND).entity(json.toString()).build();
    }
}

另外，请注意，缺省情况下，如果http代码为400或更多，Jersey将覆盖响应体。

为了得到你指定的实体作为响应体，试着在你的web.xml配置文件的Jersey中添加以下初始化参数:

    <init-param>
        <!-- used to overwrite default 4xx state pages -->
        <param-name>jersey.config.server.response.setStatusOverSendError</param-name>
        <param-value>true</param-value>
    </init-param>

如果您希望因为异常而更改状态代码，可以使用JAX-RS 2.0实现类似这样的ExceptionMapper。它为整个应用程序处理这种异常。

@Provider
public class UnauthorizedExceptionMapper implements ExceptionMapper<EJBAccessException> {

    @Override
    public Response toResponse(EJBAccessException exception) {
        return Response.status(Response.Status.UNAUTHORIZED.getStatusCode()).build();
    }

}

The answer by hisdrewness will work, but it modifies the whole approach to letting a provider such as Jackson+JAXB automatically convert your returned object to some output format such as JSON. Inspired by an Apache CXF post (which uses a CXF-specific class) I've found one way to set the response code that should work in any JAX-RS implementation: inject an HttpServletResponse context and manually set the response code. For example, here is how to set the response code to CREATED when appropriate.

@Path("/foos/{fooId}")
@PUT
@Consumes("application/json")
@Produces("application/json")
public Foo setFoo(@PathParam("fooID") final String fooID, final Foo foo, @Context final HttpServletResponse response)
{
  //TODO store foo in persistent storage
  if(itemDidNotExistBefore) //return 201 only if new object; TODO app-specific logic
  {
    response.setStatus(Response.Status.CREATED.getStatusCode());
  }
  return foo;  //TODO get latest foo from storage if needed
}

改进:在找到另一个相关的答案后，我了解到可以将HttpServletResponse作为成员变量注入，甚至对于单例服务类(至少在RESTEasy中)!!这是一种比用实现细节污染API更好的方法。它看起来是这样的:

@Context  //injected response proxy supporting multiple threads
private HttpServletResponse response;

@Path("/foos/{fooId}")
@PUT
@Consumes("application/json")
@Produces("application/json")
public Foo setFoo(@PathParam("fooID") final String fooID, final Foo foo)
{
  //TODO store foo in persistent storage
  if(itemDidNotExistBefore) //return 201 only if new object; TODO app-specific logic
  {
    response.setStatus(Response.Status.CREATED.getStatusCode());
  }
  return foo;  //TODO get latest foo from storage if needed
}