在mysql中，系统变量“max\u connections”的值为100。但我正试图通过在jdbc连接字符串中传递键值对以编程方式重写这个值jdbc:mysql：//localhost/test？maxconnections=3”。但它似乎没有反映出任何变化。下面我将maxconnection设置为3，但在下面的示例中，我仍然能够创建40个连接。注意，我并不是故意在每次迭代中关闭连接的。只是为了看看jdbc连接字符串中添加的键值是否生效。如果生效，则应该给出“too many connections”例外
参考代码如下：

public class JDBCOne {

    public static void main(String[] args) throws ClassNotFoundException, SQLException {

        for(int i=1;i<=35;i++)
            {
            Connection conn = null;  
            Statement stmt = null;

            Class.forName("com.mysql.jdbc.Driver");

            System.out.println("Connecting to database...:"+i);
            conn = DriverManager.getConnection("jdbc:mysql://localhost/test?maxConnections=3", "root", "root");
            stmt = conn.createStatement();
            Integer id = null;
            String name = null;
            Double amount = null;
            String sql = "SELECT * FROM emp where id=1";

            ResultSet rs = stmt.executeQuery(sql);

            while (rs.next()) {
                id = rs.getInt("id");
                name = rs.getString("name");
                amount = rs.getDouble("amount");
            }
            System.out.println("id-" + id);
        }
        System.out.println("Goodbye!");
    }

}