Mariadb에 접근하여 쿼리를 수행하고 필요시 정렬하여 List<Map<String, String>>에 담아서 리턴하는 메세드 예제

private final List<Map<String, String>> getResult (String query, String[] idxVals) throws Exception {
		String db_server = ;
		String db_port = ;
		String db_name = ;
		String db_user = ;
		String db_pass = ;

		Connection conn = null;
		PreparedStatement pstmt = null;
		ResultSet rs = null;

List<Map<String, String>> list = new ArrayList<Map<String, String>>();
		
		try {
			Class.forName("org.mariadb.jdbc.Driver");
			conn = DriverManager.getConnection("jdbc:mariadb://" + db_server + ":" + db_port + "/" + db_name, db_user,  db_pass);
			
			pstmt = conn.prepareStatement(query);
			rs = pstmt.executeQuery();

			int cnt = 0;
	
			ResultSetMetaData md = rs.getMetaData();
			int columns = md.getColumnCount();
			while (rs.next()){
			   HashMap<String,String> row = new HashMap<String, String>(columns);
			   for(int i=1; i<=columns; i++){           
				   row.put(md.getColumnName(i), rs.getObject(i).toString());
			   }
			   //log.debug("row("+(cnt++)+")  ===========>"+row.toString());
			    list.add(row);
			}
			
			// 정렬(test)
	        // Collections.sort(list, new MapStringComparator("rest_type"));
	        //Collections.sort(list, new MapStringComparator("corner_id"));
	        //Collections.sort(list, new MapFloatComparator("cnt"));
	        
			return list;
		} catch (Exception e) {
			throw e;
		} finally {
			if (rs != null)
				try {
					rs.close();
				} catch (SQLException sqle) {
				}
			if (pstmt != null)
				try {
					pstmt.close();
				} catch (SQLException sqle) {
				}
			if (conn != null) {
				try {
					conn.close();
				} catch (SQLException sqle) {
				}
			}
		}
	}

class MapStringComparator implements Comparator<Map<String, String>> {
		private final String key;
		
		public MapStringComparator(String key) {
			this.key = key;
		}
		
		@Override
		public int compare(Map<String, String> first, Map<String, String> second) {
			String firstValue =first.get(key);
	        String secondValue = second.get(key);
	        
	         // 내림차순 정렬
             return firstValue.compareTo(secondValue);
		}
	}

class MapFloatComparator implements Comparator<Map<String, String>> {
		private final String key;
		
		public MapFloatComparator(String key) {
			this.key = key;
		}
		
		@Override
		public int compare(Map<String, String> first, Map<String, String> second) {
			float firstValue = Float.valueOf(first.get(key));
	         float secondValue = Float.valueOf(second.get(key));
	         
			// 내림차순 정렬
	         if (firstValue > secondValue) {
	             return -1;
	         } else if (firstValue < secondValue) {
	             return 1;
	         } else /* if (firstValue == secondValue) */ {
	             return 0;
	         }
		}
	}