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.classification.InterfaceAudience;
022    import org.apache.hadoop.fs.http.client.HttpFSFileSystem;
023    import org.slf4j.Logger;
024    import org.slf4j.LoggerFactory;
025    
026    import javax.ws.rs.core.MediaType;
027    import javax.ws.rs.core.Response;
028    import javax.ws.rs.ext.ExceptionMapper;
029    import java.util.LinkedHashMap;
030    import java.util.Map;
031    
032    @InterfaceAudience.Private
033    public class ExceptionProvider implements ExceptionMapper<Throwable> {
034      private static Logger LOG = LoggerFactory.getLogger(ExceptionProvider.class);
035    
036      private static final String ENTER = System.getProperty("line.separator");
037    
038      protected Response createResponse(Response.Status status, Throwable throwable) {
039        Map<String, Object> json = new LinkedHashMap<String, Object>();
040        json.put(HttpFSFileSystem.ERROR_MESSAGE_JSON, getOneLineMessage(throwable));
041        json.put(HttpFSFileSystem.ERROR_EXCEPTION_JSON, throwable.getClass().getSimpleName());
042        json.put(HttpFSFileSystem.ERROR_CLASSNAME_JSON, throwable.getClass().getName());
043        Map<String, Object> response = new LinkedHashMap<String, Object>();
044        response.put(HttpFSFileSystem.ERROR_JSON, json);
045        log(status, throwable);
046        return Response.status(status).type(MediaType.APPLICATION_JSON).entity(response).build();
047      }
048    
049      protected String getOneLineMessage(Throwable throwable) {
050        String message = throwable.getMessage();
051        if (message != null) {
052          int i = message.indexOf(ENTER);
053          if (i > -1) {
054            message = message.substring(0, i);
055          }
056        }
057        return message;
058      }
059    
060      protected void log(Response.Status status, Throwable throwable) {
061        LOG.debug("{}", throwable.getMessage(), throwable);
062      }
063    
064      @Override
065      public Response toResponse(Throwable throwable) {
066        return createResponse(Response.Status.BAD_REQUEST, throwable);
067      }
068    
069    }