core/src/main/java/com/orientechnologies/orient/core/db/OrientDB.java
public boolean createIfNotExists(String database, ODatabaseType type) {
    return createIfNotExists(database, type, OrientDBConfig.defaultConfig());
  }
public boolean createIfNotExists(String database, ODatabaseType type) {
    return createIfNotExists(database, type, OrientDBConfig.defaultConfig());
  }
Create a new database if not exists

@param database database name
@param type     can be plocal or memory

@return true if the database has been created, false if already exists