java - Spring中，jdbcTemplate的queryForList函数作为对象返回导致NumberFormatException

Question

我正在使用 Spring JDBCTemplate，如下所示，

List<Map<String, Object>> ordersList = new ArrayList<Map<String,Object>>();

String sql = "SELECT aa.Barcode, aa.ItemName, aa.Quantity AS Qty\n" +
                    "FROM\n" +
                    "(SELECT Barcode, ItemName, Quantity\n" +
                    "FROM PurchaseDetails\n" +
                    "UNION\n" +
                    "SELECT Barcode, ItemName, Quantity\n" +
                    "FROM BarcodePrinting) aa";
System.out.println(sql);

jdbcTemplate = new JdbcTemplate(dataSource);
ordersList = jdbcTemplate.queryForList(sql);

System.out.println("ordersList= "+ordersList.toString());

在上述代码的结果中系统打印为，

SELECT aa.Barcode, aa.ItemName, aa.Quantity AS Qty
FROM
(SELECT Barcode, ItemName, Quantity
FROM PurchaseDetails
UNION
SELECT Barcode, ItemName, Quantity
FROM BarcodePrinting) aa
ordersList= [{Barcode=8901030627330, ItemName=Lux Soft Touch, Qty=[B@72d4ef0c}, {Barcode=8901396393511, ItemName=Dettol org, Qty=[B@799a37b9}]

因此，插入 Integer Return 它返回为

[B@72d4ef0c

但是之前，我在数据库中尝试过这个查询，它按预期返回正确的数字。

请帮助我。

Answer 1

[B@72d4ef0c

表示它是一个字节数组。尝试按如下方式更改 SQL

String sql = "SELECT aa.Barcode, aa.ItemName, SUM(aa.Quantity) AS Qty\n" +
                    "FROM\n" +
                    "(SELECT Barcode, ItemName, Quantity\n" +
                    "FROM PurchaseDetails\n" +
                    "UNION\n" +
                    "SELECT Barcode, ItemName, Quantity\n" +
                    "FROM BarcodePrinting) aa\n " +
                    "GROUP BY aa.Barcode, aa.ItemName";