jdbc连接数据库进行数据查询，返回对象，返回值自定义 把 大概代码贴一下，自己连接，仅执行语句返回内容

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/**      * 查询sql      *      * @param: sql      * @return: JSONArray      */     public static JSONArray querySql(PostgreSQLConfig staticPostgreSQLConfig, String sql, Object... objects) {         JSONArray resJson = null;         Connection conn = null;         PreparedStatement pstmt = null;         ResultSet reSet = null;         PGConnectionPool connPool = null;         try { //            conn = getConnection(staticPostgreSQLConfig);             connPool = PGConnectionPoolUtil.getPoolInstance(staticPostgreSQLConfig);             conn = connPool.getConnection();             pstmt = conn.prepareStatement(sql);             if (objects != null && objects.length > 0) {                 for (int i = 0; i < objects.length; i++) {                     pstmt.setObject(i + 1, objects[i]);                 }             }             logger.info("执行SQL：{}", sql);             reSet = pstmt.executeQuery();             // 获取列数             ResultSetMetaData metaData = reSet.getMetaData();             int columnCount = metaData.getColumnCount();             // 遍历ResultSet中的每条数据             while (reSet.next()) {                 JSONObject jsonObj = new JSONObject();                 // 获取每一列数据                 for (int i = 1; i <= columnCount; i++) {                     String value = "";                     String columnName = metaData.getColumnLabel(i);//列名称                     if (reSet.getString(columnName) != null && !reSet.getString(columnName).equals("")) {                         value = new String(reSet.getBytes(columnName), "UTF-8");//列的值,有数据则转码                     }                     jsonObj.put(columnName, value);                 }                 resJson.add(jsonObj);             }         } catch (Exception e) {             e.printStackTrace();         } finally { //            closeConnection(conn, pstmt, reSet);             closePoolConnection(connPool, conn, pstmt, reSet);         }         return resJson;     }         public static <T> List<T> querySql(PostgreSQLConfig staticPostgreSQLConfig, Class<T> clazz, String sql, Object... objects) {         List<T> resList = new ArrayList<>();         Connection conn = null;         PreparedStatement pstmt = null;         ResultSet reSet = null;         PGConnectionPool connPool = null;         try { //            conn = getConnection(staticPostgreSQLConfig);             connPool = PGConnectionPoolUtil.getPoolInstance(staticPostgreSQLConfig);             conn = connPool.getConnection();             pstmt = conn.prepareStatement(sql);             if (objects != null && objects.length > 0) {                 for (int i = 0; i < objects.length; i++) {                     pstmt.setObject(i + 1, objects[i]);                 }             }             logger.info("执行SQL：{}", sql);             reSet = pstmt.executeQuery();             List<Map<String, Object>> tempList = new ArrayList<>();             Map<String, Object> tempMap = null;             // 获取列数             ResultSetMetaData metaData = reSet.getMetaData();             int columnCount = metaData.getColumnCount();             // 遍历ResultSet中的每条数据             while (reSet.next()) {                 tempMap = new HashMap<>();                 for (int i = 1; i <= columnCount; i++) {                     String columnName = metaData.getColumnLabel(i);//列名称                     tempMap.put(columnName, reSet.getObject(i));                 }                 tempList.add(tempMap);             }             //加载数据到对象             if (tempList.size() > 0) {                 for (Map<String, Object> map : tempList) {                     //解析对象                     T bean = clazz.newInstance();                     for (Map.Entry<String, Object> entry : map.entrySet()) {                         String propertyName = entry.getKey();                         Object value = entry.getValue();                         Field field = clazz.getDeclaredField(propertyName);                         String str = field.getName();                         String s = str.substring(0, 1).toUpperCase() + str.substring(1);                         Method method = clazz.getMethod("set" + s, field.getType());                         method.invoke(bean, value);                     }                     resList.add(bean);                 }             }         } catch (Exception e) {             e.printStackTrace();         } finally { //            closeConnection(conn, pstmt, reSet);             closePoolConnection(connPool, conn, pstmt, reSet);         }         return resList;     } /**      * 关闭连接      */     public static void closePoolConnection(PGConnectionPool connPool, Connection conn, PreparedStatement pstmt, ResultSet reSet) {         try {             if (pstmt != null) {                 pstmt.close();             }         } catch (SQLException e) {             e.printStackTrace();         } finally {             if (reSet != null) {                 try {                     reSet.close();                 } catch (SQLException e) {                     e.printStackTrace();                 } finally {                     try {                         if (conn != null) {                             connPool.returnConnection(conn);                         }                     } catch (Exception e) {                         e.printStackTrace();                     }                 }             }         }     }