【Java/MySQL】Unknown system variable 'language'

调试一简单JDBC连MySQL的程序，发现出现异常，导致连接无法成功，报错信息是：Unknown system variable 'language'

解决方案：在pom.xml里，将原有的版本降下来，我的就从5.1.36降低到了5.1.24

        <!-- mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.24</version>
        </dependency>

之后程序就运行正常了，代码如下：

package com.mq;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.MessageFormat;

public class Test {

    private static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    private static final String DB_URL = "jdbc:mysql://127.0.0.1:3306/test";
    private static final String USER = "root";
    private static final String PSWD = "hy";

    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;

        try {
            Class.forName(JDBC_DRIVER).newInstance();
            conn = DriverManager.getConnection(DB_URL, USER, PSWD);

            stmt = conn.createStatement();
            String sql = "select id,name,age from testtb order by id limit 10";
            ResultSet rs = stmt.executeQuery(sql);

            int index = 0;
            while (rs.next()) {
                index++;

                String id = rs.getString("id");
                String name = rs.getString("name");
                String age = rs.getString("age");

                String raw = "#{0},{1},{2},{3},{4}";
                Object[] arr = { index, id, name, age };
                String outStr = MessageFormat.format(raw, arr);
                System.out.println(outStr);
            }
        } catch (Exception e) {
            System.out.print("DB/SQL ERROR:" + e.getMessage());
        } finally {
            try {
                stmt.close();
                conn.close();
            } catch (SQLException e) {
                System.out.print("Can't close stmt/conn because of " + e.getMessage());
            }
            
        }
    }
}

执行结果：

#1,1,andy,20,{4}
#2,2,bill,30,{4}

数据库里情况：

mysql> select * from testtb;
+----+------+------+
| id | name | age  |
+----+------+------+
|  1 | andy |   20 |
|  2 | bill |   30 |
+----+------+------+
2 rows in set (0.00 sec)

END