/*
* Copyright 2015 MongoDB, Inc.
*
* 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 course;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import sun.misc.BASE64Encoder;
import java.security.SecureRandom;
import static com.mongodb.client.model.Filters.eq;
public class SessionDAO {
private final MongoCollection<Document> sessionsCollection;
public SessionDAO(final MongoDatabase blogDatabase) {
sessionsCollection = blogDatabase.getCollection("sessions");
}
public String findUserNameBySessionId(String sessionId) {
Document session = getSession(sessionId);
if (session == null) {
return null;
} else {
return session.get("username").toString();
}
}
// starts a new session in the sessions table
public String startSession(String username) {
// get 32 byte random number. that's a lot of bits.
SecureRandom generator = new SecureRandom();
byte randomBytes[] = new byte[32];
generator.nextBytes(randomBytes);
BASE64Encoder encoder = new BASE64Encoder();
String sessionID = encoder.encode(randomBytes);
// build the BSON object
Document session = new Document("username", username)
.append("_id", sessionID);
sessionsCollection.insertOne(session);
return session.getString("_id");
}
// ends the session by deleting it from the sesisons table
public void endSession(String sessionID) {
sessionsCollection.deleteOne(eq("_id", sessionID));
}
// retrieves the session from the sessions table
public Document getSession(String sessionID) {
return sessionsCollection.find(eq("_id", sessionID)).first();
}
}