JdbcTemplate queryForMap get（）为有效密钥返回null

Question

对MySQL表的简单JdbcTemplate.queryForMap（）调用会产生这种奇怪的可解释行为。映射输出为get（）返回null，并为keySet（）和values（）返回预期结果。

编辑： -张贴完整的课程代码 -使用RowMapper（）实现的附加查询。

这是表模式：

create table Product(
    id int not null primary key auto_increment,
    `name` varchar(30),
    price decimal(10,2)
);

mysql> select * from Product;
+----+--------+-------+
| id | name   | price |
+----+--------+-------+
|  1 | iPhone | 10.00 |
+----+--------+-------+
1 row in set (0.00 sec)

完整的Java类：

package com.test1;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.dbcp2.BasicDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

/**
 * 
 * @author user2176499
 *
 */
public class Main {

    private static final Logger logger = LoggerFactory.getLogger(Main.class);

    public static void main(String[] args) throws Exception {

        BasicDataSource dataSource = new BasicDataSource();
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://127.0.0.1:3306/testdb");
        dataSource.setUsername("user");
        dataSource.setPassword("password");
        JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

        Map<String, Object> row = jdbcTemplate.queryForMap("select * from Product where id=?", 1);

        System.out.println(row.getClass());
        System.out.println(row.keySet());
        System.out.println(row.values());
        System.out.println(row.containsKey("name"));
        System.out.println(row.get("name"));

        Iterator<String> iterator = row.keySet().iterator();
        while (iterator.hasNext()) {
            String key = iterator.next();
            System.out.println(key + " - " + row.get(key));
        }

        System.out.println("==================");

        List<Map<String, Object>> rows = jdbcTemplate.query("select * from Product where id=?", new Object[] { 1 },
                new RowMapper<Map<String, Object>>() {

                    @Override
                    public Map<String, Object> mapRow(ResultSet rs, int rowNum) throws SQLException {
                        return Map.ofEntries(Map.entry("id", rs.getInt("id")), Map.entry("name", rs.getString("name")),
                                Map.entry("price", rs.getDouble("price")));
                    }
                });
        System.out.println(rows);
    }
}

输出：

class org.springframework.util.LinkedCaseInsensitiveMap
[id, name, price]
[1, iPhone, 10.00]
false
null
id - null
name - null
price - null
==================
[{name=iPhone, price=10.0, id=1}]

Spring版本：spring-jdbc-5.2.2-release