/**
* 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.marmotta.client.clients;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.marmotta.client.ClientConfiguration;
import org.apache.marmotta.client.exception.ContentFormatException;
import org.apache.marmotta.client.exception.MarmottaClientException;
import org.apache.marmotta.client.exception.NotFoundException;
import org.apache.marmotta.client.model.rdf.RDFNode;
import org.apache.marmotta.client.util.HTTPUtil;
import org.apache.marmotta.client.util.RDFJSONParser;
import org.codehaus.jackson.JsonParser;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.type.TypeReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Add file description here!
* <p/>
* Author: Sebastian Schaffert
*/
public class LDPathClient {
private static Logger log = LoggerFactory.getLogger(LDPathClient.class);
private static final String URL_PATH_SERVICE = "/ldpath/path";
private static final String URL_PROGRAM_SERVICE = "/ldpath/program";
private ClientConfiguration config;
public LDPathClient(ClientConfiguration config) {
this.config = config;
}
/**
* Evaluate the path query passed as second argument, starting at the resource with the uri given as first argument.
* Returns a List of RDFNode objects.
*
*
* @param uri the uri of the resource where to start the path evaluation
* @param path the path to evaluate
* @return a list of RDFNodes representing the result of the path evaluation as returned by the server
* @throws MarmottaClientException
* @throws IOException
*/
public List<RDFNode> evaluatePath(String uri, String path) throws MarmottaClientException, IOException {
HttpClient httpClient = HTTPUtil.createClient(config);
String serviceUrl = config.getMarmottaUri() + URL_PATH_SERVICE + "?path=" + URLEncoder.encode(path, "utf-8")
+ "&uri=" + URLEncoder.encode(uri, "utf-8");
HttpGet get = new HttpGet(serviceUrl);
get.setHeader("Accept", "application/json");
try {
HttpResponse response = httpClient.execute(get);
switch(response.getStatusLine().getStatusCode()) {
case 200:
log.debug("LDPath Path Query {} evaluated successfully",path);
ObjectMapper mapper = new ObjectMapper();
mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
List<Map<String,String>> serverResult =
mapper.readValue(response.getEntity().getContent(),new TypeReference<List<Map<String,String>>>(){});
List<RDFNode> result = new ArrayList<RDFNode>();
for(Map<String,String> value : serverResult) {
result.add(RDFJSONParser.parseRDFJSONNode(value));
}
return result;
case 400:
log.error("the server did not accept the uri ({}) or path ({}) arguments",uri,path);
throw new ContentFormatException("the server did not accept the uri ("+uri+") or path ("+path+") arguments");
case 404:
log.error("the resource with URI {} does not exist on the server",uri);
throw new NotFoundException("the resource with URI "+uri+" does not exist on the server");
default:
log.error("error evaluating LDPath Path Query {}: {} {}",new Object[] {path,response.getStatusLine().getStatusCode(),response.getStatusLine().getReasonPhrase()});
throw new MarmottaClientException("error evaluating LDPath Path Query "+path+": "+response.getStatusLine().getStatusCode() + " " + response.getStatusLine().getReasonPhrase());
}
} finally {
get.releaseConnection();
}
}
public Map<String,List<RDFNode>> evaluateProgram(String uri, String program) throws MarmottaClientException, IOException {
HttpClient httpClient = HTTPUtil.createClient(config);
String serviceUrl = config.getMarmottaUri() + URL_PROGRAM_SERVICE + "?program=" + URLEncoder.encode(program, "utf-8")
+ "&uri=" + URLEncoder.encode(uri, "utf-8");
HttpGet get = new HttpGet(serviceUrl);
get.setHeader("Accept", "application/json");
try {
HttpResponse response = httpClient.execute(get);
switch(response.getStatusLine().getStatusCode()) {
case 200:
log.debug("LDPath Program Query evaluated successfully:\n{}",program);
ObjectMapper mapper = new ObjectMapper();
mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
Map<String,List<Map<String,String>>> serverResult =
mapper.readValue(response.getEntity().getContent(),new TypeReference<Map<String,List<Map<String,String>>>>(){});
Map<String,List<RDFNode>> result = new HashMap<String, List<RDFNode>>();
for(Map.Entry<String,List<Map<String,String>>> field : serverResult.entrySet()) {
List<RDFNode> row = new ArrayList<RDFNode>();
for(Map<String,String> node : field.getValue()) {
row.add(RDFJSONParser.parseRDFJSONNode(node));
}
result.put(field.getKey(),row);
}
return result;
case 400:
log.error("the server did not accept the uri ({}) or program ({}) arguments",uri,program);
throw new ContentFormatException("the server did not accept the uri ("+uri+") or program ("+program+") arguments");
case 404:
log.error("the resource with URI {} does not exist on the server",uri);
throw new NotFoundException("the resource with URI "+uri+" does not exist on the server");
default:
log.error("error evaluating LDPath Program Query: {} {}",new Object[] {response.getStatusLine().getStatusCode(),response.getStatusLine().getReasonPhrase()});
throw new MarmottaClientException("error evaluating LDPath Program Query: "+response.getStatusLine().getStatusCode() + " " + response.getStatusLine().getReasonPhrase());
}
} finally {
get.releaseConnection();
}
}
}