mysql哪个连接未释放

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class MySQLConnectionExample {
    public static void main(String[] args) {
        Connection conn = null;
        try {
            // 获取数据库连接
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "username", "password");
            // 执行数据库操作
            // ...
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            // 关闭连接
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}