package examples; import org.mapdb.DB; import org.mapdb.DBMaker; import java.io.File; import java.io.IOException; import java.util.concurrent.ConcurrentNavigableMap; /** * Hello world application to demonstrate storage open, commit and close operations */ public class _HelloWorld { public static void main(String[] args) throws IOException { //Configure and open database using builder pattern. //All options are available with code auto-completion. File dbFile = File.createTempFile("mapdb","db"); DB db = DBMaker.newFileDB(dbFile) .closeOnJvmShutdown() .encryptionEnable("password") .make(); //open an collection, TreeMap has better performance then HashMap ConcurrentNavigableMap map = db.getTreeMap("collectionName"); map.put(1,"one"); map.put(2,"two"); //map.keySet() is now [1,2] even before commit db.commit(); //persist changes into disk map.put(3,"three"); //map.keySet() is now [1,2,3] db.rollback(); //revert recent changes //map.keySet() is now [1,2] db.close(); } }