/*
* Copyright Myrrix Ltd
*
* Licensed 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 net.myrrix.web.servlets;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.mahout.cf.taste.common.TasteException;
import net.myrrix.common.MyrrixRecommender;
/**
* <p>Responds to a POST request to {@code /tag/user/[userID]/[tag]} and in turn calls
* {@link MyrrixRecommender#setUserTag(long, String, float)}. If the request body is empty,
* the value is 1.0, otherwise the value in the request body's first line is used.</p>
*
* @author Sean Owen
* @since 1.0
*/
public final class TagUserServlet extends AbstractMyrrixServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException {
CharSequence pathInfo = request.getPathInfo();
if (pathInfo == null) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No path");
return;
}
Iterator<String> pathComponents = SLASH.split(pathInfo).iterator();
long userID;
String userTag;
try {
userID = Long.parseLong(pathComponents.next());
userTag = pathComponents.next();
} catch (NoSuchElementException nsee) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST, nsee.toString());
return;
} catch (NumberFormatException nfe) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST, nfe.toString());
return;
}
if (pathComponents.hasNext()) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Path too long");
return;
}
float tagValue;
try {
tagValue = PreferenceServlet.readValue(request);
} catch (IllegalArgumentException ignored) {
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Bad value");
return;
}
MyrrixRecommender recommender = getRecommender();
try {
recommender.setUserTag(userID, userTag, tagValue);
} catch (TasteException te) {
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, te.toString());
getServletContext().log("Unexpected error in " + getClass().getSimpleName(), te);
}
}
@Override
protected Long getUnnormalizedPartitionToServe(HttpServletRequest request) {
CharSequence pathInfo = request.getPathInfo();
if (pathInfo == null) {
return null;
}
Iterator<String> pathComponents = SLASH.split(pathInfo).iterator();
long userID;
try {
userID = Long.parseLong(pathComponents.next());
} catch (NoSuchElementException ignored) {
return null;
} catch (NumberFormatException ignored) {
return null;
}
return userID;
}
}