LinkedHashMap 記錄插入順序

 1             statement = conn.createStatement();
 2             resultSet = statement.executeQuery(sql);
 3             ResultSetMetaData rsmd = resultSet.getMetaData();
 4             int count = rsmd.getColumnCount();
 5             while (resultSet.next()) {
 6                 LinkedHashMap<String,Object> hm=new LinkedHashMap<String,Object>(count);
 7                 for (int i = 1; i <= count; i++) {
 8                     String key = rsmd.getColumnLabel(i);
 9                     Object value = resultSet.getObject(i);
10                     hm.put(key, value);
11                 }
12                 item.add(hm);
13             }

需求是執行輸入的sql,返回查詢結果。結果在頁面上數據列顯示很隨意，沒有和數據庫表字段保持一致。

解決方案：把HashMap替換爲LinkedHashMap