package examples; import org.mapdb.BTreeMap; import org.mapdb.DBMaker; import java.util.Map; /** * Opens maps backed by file in temporary folder. * Quick and simple way to get Maps which can handle billions of items. * All files are deleted after Map is closed or JVM exits (using shutdown hook). */ public class _TempMap { public static void main(String[] args) { // open new empty map // DBMaker will create files in temporary folder and opens it Map map = DBMaker.newTempTreeMap(); //put some stuff into map //all data are stored in file in temp folder map.put("aa", "bb"); map.put("cc", "dd"); // Close map to release resources. // It is optional, there is JVM shutdown hook which deletes files on JVM exit. ((BTreeMap)map).close(); // After JVM exits files are deleted. // This map was temporary, there is no way to recover its data ! } }