/**
* 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.services;
import org.apache.ambari.server.api.resources.ResourceInstance;
import org.apache.ambari.server.api.resources.ResourceInstanceFactory;
import org.apache.ambari.server.api.resources.ResourceInstanceFactoryImpl;
import org.apache.ambari.server.api.services.parsers.BodyParseException;
import org.apache.ambari.server.api.services.parsers.JsonRequestBodyParser;
import org.apache.ambari.server.api.services.parsers.RequestBodyParser;
import org.apache.ambari.server.api.services.serializers.JsonSerializer;
import org.apache.ambari.server.api.services.serializers.ResultSerializer;
import org.apache.ambari.server.controller.spi.Resource;
import org.eclipse.jetty.util.ajax.JSON;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* Provides common functionality to all services.
*/
public abstract class BaseService {
/**
* Factory for creating resource instances.
*/
private ResourceInstanceFactory m_resourceFactory = new ResourceInstanceFactoryImpl();
/**
* Result serializer.
*/
private ResultSerializer m_serializer = new JsonSerializer();
/**
* Requests are funneled through this method so that common logic can be executed.
* Creates a request instance and invokes it's process method. Uses the default
* media type.
*
* @param headers http headers
* @param body http body
* @param uriInfo uri information
* @param requestType http request type
* @param resource resource instance that is being acted on
*
* @return the response of the operation in serialized form
*/
protected Response handleRequest(HttpHeaders headers, String body, UriInfo uriInfo,
Request.Type requestType, ResourceInstance resource) {
return handleRequest(headers, body, uriInfo, requestType, null, resource);
}
/**
* Requests are funneled through this method so that common logic can be executed.
* Creates a request instance and invokes it's process method.
*
* @param headers http headers
* @param body http body
* @param uriInfo uri information
* @param requestType http request type
* @param mediaType the requested media type; may be null
* @param resource resource instance that is being acted on
*
* @return the response of the operation in serialized form
*/
protected Response handleRequest(HttpHeaders headers, String body,
UriInfo uriInfo, Request.Type requestType,
MediaType mediaType, ResourceInstance resource) {
Result result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.OK));
try {
Set<RequestBody> requestBodySet = getBodyParser().parse(body);
Iterator<RequestBody> iterator = requestBodySet.iterator();
while (iterator.hasNext() && result.getStatus().getStatus().equals(ResultStatus.STATUS.OK)) {
RequestBody requestBody = iterator.next();
Request request = getRequestFactory().createRequest(
headers, requestBody, uriInfo, requestType, resource);
result = request.process();
}
} catch (BodyParseException e) {
result = new ResultImpl(new ResultStatus(ResultStatus.STATUS.BAD_REQUEST, e.getMessage()));
}
ResultSerializer serializer = mediaType == null ? getResultSerializer() : getResultSerializer(mediaType);
Response.ResponseBuilder builder = Response.status(result.getStatus().getStatusCode()).entity(
serializer.serialize(result));
if (mediaType != null) {
builder.type(mediaType);
}
return builder.build();
}
/**
* Obtain the factory from which to create Request instances.
*
* @return the Request factory
*/
RequestFactory getRequestFactory() {
return new RequestFactory();
}
/**
* Create a resource instance.
*
* @param type the resource type
* @param mapIds all primary and foreign key properties and values
*
* @return a newly created resource instance
*/
ResourceInstance createResource(Resource.Type type, Map<Resource.Type, String> mapIds) {
return m_resourceFactory.createResource(type, mapIds);
}
/**
* Get a serializer for the given media type.
*
* @param mediaType the media type
*
* @return the result serializer
*/
protected ResultSerializer getResultSerializer(final MediaType mediaType) {
final ResultSerializer serializer = getResultSerializer();
if (mediaType.equals(MediaType.TEXT_PLAIN_TYPE)){
return new ResultSerializer() {
@Override
public Object serialize(Result result) {
return serializer.serialize(result).toString();
}
@Override
public Object serializeError(ResultStatus error) {
return serializer.serializeError(error).toString();
}
};
} else if (mediaType.equals(MediaType.APPLICATION_JSON_TYPE)){
return new ResultSerializer() {
@Override
public Object serialize(Result result) {
return JSON.parse(serializer.serialize(result).toString());
}
@Override
public Object serializeError(ResultStatus error) {
return JSON.parse(serializer.serializeError(error).toString());
}
};
}
throw new IllegalArgumentException("The media type " + mediaType + " is not supported.");
}
/**
* Get the default serializer.
*
* @return the default serializer
*/
protected ResultSerializer getResultSerializer() {
return m_serializer;
}
protected RequestBodyParser getBodyParser() {
return new JsonRequestBodyParser();
}
}