/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.ambari.server.api.handlers;
import org.apache.ambari.server.api.services.Request;
import org.apache.ambari.server.api.services.ResultImpl;
import org.apache.ambari.server.api.services.ResultStatus;
import org.apache.ambari.server.api.services.Result;
import org.apache.ambari.server.api.query.Query;
import org.apache.ambari.server.controller.spi.*;
import org.apache.ambari.server.controller.utilities.PropertyHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Map;
/**
* Responsible for read requests.
*/
public class ReadHandler implements RequestHandler {
/**
* Logger instance.
*/
private final static Logger LOG =
LoggerFactory.getLogger(ReadHandler.class);
@Override
public Result handleRequest(Request request) {
Query query = request.getResource().getQuery();
query.setPageRequest(request.getPageRequest());
query.setMinimal(request.isMinimal());
try {
addFieldsToQuery(request, query);
} catch (IllegalArgumentException e) {
return new ResultImpl(new ResultStatus(ResultStatus.STATUS.BAD_REQUEST, e.getMessage()));
}
Result result;
Predicate p = null;
try {
p = request.getQueryPredicate();
query.setUserPredicate(p);
result = query.execute();
result.setResultStatus(new ResultStatus(ResultStatus.STATUS.OK));
} catch (SystemException e) {
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.SERVER_ERROR, e));
} catch (NoSuchParentResourceException e) {
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.NOT_FOUND, e.getMessage()));
} catch (UnsupportedPropertyException e) {
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.BAD_REQUEST, e.getMessage()));
} catch (NoSuchResourceException e) {
if (p == null) {
// no predicate specified, resource requested by id
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.NOT_FOUND, e.getMessage()));
} else {
// resource(s) requested using predicate
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.OK, e));
result.getResultTree().setProperty("isCollection", "true");
}
} catch (IllegalArgumentException e) {
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.BAD_REQUEST,
"Invalid Request: " + e.getMessage()));
LOG.error("Bad request: ", e);
} catch (RuntimeException e) {
if (LOG.isErrorEnabled()) {
LOG.error("Caught a runtime exception executing a query", e);
}
//result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.SERVER_ERROR, e));
throw e;
}
return result;
}
/**
* Add partial response fields to the provided query.
*
* @param request the current request
* @param query the associated query *
*/
private void addFieldsToQuery(Request request, Query query) {
//Partial response
for (Map.Entry<String, TemporalInfo> entry : request.getFields().entrySet()) {
// Iterate over map and add props/temporalInfo
String propertyId = entry.getKey();
query.addProperty(propertyId, entry.getValue());
}
}
}