001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package org.apache.hadoop.lib.wsrs;
020    
021    import org.apache.hadoop.fs.http.client.HttpFSFileSystem;
022    import org.slf4j.Logger;
023    import org.slf4j.LoggerFactory;
024    
025    import javax.ws.rs.core.MediaType;
026    import javax.ws.rs.core.Response;
027    import javax.ws.rs.ext.ExceptionMapper;
028    import java.util.LinkedHashMap;
029    import java.util.Map;
030    
031    public class ExceptionProvider implements ExceptionMapper<Throwable> {
032      private static Logger LOG = LoggerFactory.getLogger(ExceptionProvider.class);
033    
034      private static final String ENTER = System.getProperty("line.separator");
035    
036      protected Response createResponse(Response.Status status, Throwable throwable) {
037        Map<String, Object> json = new LinkedHashMap<String, Object>();
038        json.put(HttpFSFileSystem.ERROR_MESSAGE_JSON, getOneLineMessage(throwable));
039        json.put(HttpFSFileSystem.ERROR_EXCEPTION_JSON, throwable.getClass().getSimpleName());
040        json.put(HttpFSFileSystem.ERROR_CLASSNAME_JSON, throwable.getClass().getName());
041        Map<String, Object> response = new LinkedHashMap<String, Object>();
042        response.put(HttpFSFileSystem.ERROR_JSON, json);
043        log(status, throwable);
044        return Response.status(status).type(MediaType.APPLICATION_JSON).entity(response).build();
045      }
046    
047      protected String getOneLineMessage(Throwable throwable) {
048        String message = throwable.getMessage();
049        if (message != null) {
050          int i = message.indexOf(ENTER);
051          if (i > -1) {
052            message = message.substring(0, i);
053          }
054        }
055        return message;
056      }
057    
058      protected void log(Response.Status status, Throwable throwable) {
059        LOG.debug("{}", throwable.getMessage(), throwable);
060      }
061    
062      @Override
063      public Response toResponse(Throwable throwable) {
064        return createResponse(Response.Status.BAD_REQUEST, throwable);
065      }
066    
067    }