帮忙解释下这个的用处哈
public class C3poData {public Map<String, String> pickMatch() { Map<String, String> runningmap = new HashMap<String, String>(); con = ConnectionFactory.getConnection(); String runningsql = "SELECT MATCH_ID,RUNNING_BALL FROM T_FMS_OG_MATCH"; try { pstmt = con.prepareStatement(runningsql); rs = pstmt.executeQuery(); while(rs.next()){ runningmap.put(rs.getString(1), rs.getString(2)); } rs.close(); pstmt.close(); con.close(); } catch (SQLException e) { logger.info(e.getMessage(), e); } return runningmap; }}