原生JDBC操作結果集

Class.forName(className);
			Connection con = DriverManager.getConnection(jdbcUrl, username, password);
			PreparedStatement prepareStatement = con.prepareStatement(sql);
			if((sql.contains("select")&&sql.contains("from")) || (sql.contains("SELECT")&&sql.
 
contains("FROM"))) {
				ResultSet resultSet = prepareStatement.executeQuery();
				ResultSetMetaData metaData = resultSet.getMetaData();
				 LinkedHashMap<String, Object> map = null;
				 //所有結果集
				 List<LinkedHashMap<String ,Object>> list=new ArrayList<>();
		            while
 
 (resultSet.next()) {
		                //把一條記錄放入Map中
		                map = new LinkedHashMap<String, Object>();
		                for (int i = 0; i < metaData.getColumnCount(); i++) {
		                    String columnLabel = metaData.getColumnLabel(i + 1);
		                    Object value =
 
 resultSet.getObject(i + 1);
		                    map.put(columnLabel, value);
		                }
		                list.add(map);
		               System.out.println(map);
		               //所有表字段
		               List<String> titleList=new ArrayList<>();
		               LinkedHashMap<String,Object> linkedHashMap = list.get(0);
		               Set<String> keySet = linkedHashMap.keySet();
		               Iterator<String> iterator = keySet.iterator();
		               while(iterator.hasNext()) {
		            	   String key = iterator.next();
		            	   titleList.add(key);
		               }
		               model.addAttribute("title",titleList);
		               model.addAttribute("list", list);
		            }
			}else {
				//增，刪，改操作
				 boolean flag = prepareStatement.execute(sql);
				 model.addAttribute("flag",flag);
			}