question: get an instance of the jdbcpersistencemanager . it implements a lazy initialization with double checked locking . concode_field_sep Log log concode_elem_sep JDBCPersistenceManager instance concode_elem_sep DataSource dataSource concode_field_sep Connection getDBConnection concode_elem_sep void initDataSource concode_elem_sep void initializeDatabase
target: JDBCPersistenceManager function ( ) { if ( instance == null ) { synchronized ( JDBCPersistenceManager . class ) { if ( instance == null ) { instance = new JDBCPersistenceManager ( ) ; } } } return instance ; }