// This file is part of MongoMVCC.
//
// Copyright (c) 2012 Fraunhofer IGD
//
// MongoMVCC is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// MongoMVCC is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with MongoMVCC. If not, see <http://www.gnu.org/licenses/>.
package de.fhg.igd.mongomvcc.fiveminutes;
import java.util.Map;
import de.fhg.igd.mongomvcc.VBranch;
import de.fhg.igd.mongomvcc.VCollection;
import de.fhg.igd.mongomvcc.VConstants;
import de.fhg.igd.mongomvcc.VCursor;
import de.fhg.igd.mongomvcc.VDatabase;
import de.fhg.igd.mongomvcc.VFactory;
import de.fhg.igd.mongomvcc.impl.MongoDBVFactory;
/**
* <p>Demonstrates the use of MongoMVCC in 5 minutes.</p>
* <p>See the <a href="https://github.com/igd-geo/mongomvcc/wiki/5-Minutes-Tutorial">online
* tutorial</a> for a complete description.</p>
* @author Michel Kraemer
*/
public class FiveMinutes {
/**
* Runs the tutorial
* @param args the program arguments
*/
public static void main(String[] args) {
// 1. Connect to a database
VFactory factory = new MongoDBVFactory();
VDatabase db = factory.createDatabase();
db.connect("mongomvcc-five-minutes-tutorial");
// Checkout the "master" branch
VBranch master = db.checkout(VConstants.MASTER);
// 2. Put something into the index
VCollection persons = master.getCollection("persons");
Map<String, Object> elvis = factory.createDocument();
elvis.put("name", "Elvis");
elvis.put("age", 3);
persons.insert(elvis);
// insert another person
persons.insert(factory.createDocument("name", "Peter"));
// 3. Commit index to the database
long firstCid = master.commit();
// 4. Read documents from the database
VCursor c = persons.find();
for (Map<String, Object> person : c) {
System.out.print("Person { name: " + person.get("name"));
if (person.containsKey("age")) {
System.out.print(", age: " + person.get("age"));
}
System.out.println(" }");
}
Map<String, Object> elvis2 = persons.findOne(factory.createDocument("name", "Elvis"));
if (elvis2 != null) {
System.out.println("Elvis lives!");
}
// 5. Make another commit
persons.insert(factory.createDocument("name", "Max"));
elvis.put("age", 4);
persons.insert(elvis);
master.commit();
// 6. Checkout a previous version
System.out.println("There are " + persons.find().size() + " persons");
Map<String, Object> elvis3 = persons.findOne(factory.createDocument("name", "Elvis"));
System.out.println("Elvis is now " + elvis3.get("age") + " years old");
VBranch oldMaster = db.checkout(firstCid);
VCollection oldPersons = oldMaster.getCollection("persons");
System.out.println("Previously, there were only " + oldPersons.find().size() + " persons");
Map<String, Object> oldElvis = oldPersons.findOne(factory.createDocument("name", "Elvis"));
System.out.println("Last year, Elvis was " + oldElvis.get("age") + " years old");
// 7. Drop the database
db.drop();
}
}