| /* |
| * Copyright 2015-present Open Networking Foundation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.onlab.rest.exceptions; |
| |
| import com.fasterxml.jackson.databind.ObjectMapper; |
| import com.fasterxml.jackson.databind.node.ObjectNode; |
| |
| import javax.ws.rs.core.Response; |
| import javax.ws.rs.ext.ExceptionMapper; |
| |
| import static com.google.common.base.Strings.isNullOrEmpty; |
| |
| /** |
| * Base exception mapper implementation. |
| */ |
| public abstract class AbstractMapper<E extends Throwable> implements ExceptionMapper<E> { |
| |
| /** |
| * Holds the current exception for use in subclasses. |
| */ |
| protected Throwable error; |
| |
| /** |
| * Returns the response status to be given when the exception occurs. |
| * |
| * @return response status |
| */ |
| protected abstract Response.Status responseStatus(); |
| |
| @Override |
| public Response toResponse(E exception) { |
| error = exception; |
| return response(responseStatus(), exception).build(); |
| } |
| |
| /** |
| * Produces a response builder primed with the supplied status code |
| * and JSON entity with the status code and exception message. |
| * |
| * @param status response status |
| * @param exception exception to encode |
| * @return response builder |
| */ |
| protected Response.ResponseBuilder response(Response.Status status, |
| Throwable exception) { |
| error = exception; |
| ObjectMapper mapper = new ObjectMapper(); |
| String message = messageFrom(exception); |
| ObjectNode result = mapper.createObjectNode() |
| .put("code", status.getStatusCode()) |
| .put("message", message); |
| return Response.status(status).entity(result.toString()); |
| } |
| |
| /** |
| * Produces a response message from the supplied exception. Either it will |
| * use the exception message, if there is one, or it will use the top |
| * stack-frame message. |
| * |
| * @param exception exception from which to produce a message |
| * @return response message |
| */ |
| protected String messageFrom(Throwable exception) { |
| if (isNullOrEmpty(exception.getMessage())) { |
| StackTraceElement[] trace = exception.getStackTrace(); |
| return trace.length == 0 ? "Unknown error" : trace[0].toString(); |
| } |
| return exception.getMessage(); |
| } |
| |
| } |