获取不到web.xml中配置的上下文参数context-param

问题相关代码，请勿粘贴截图

public class ContextServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        ServletContext context = getServletConfig().getServletContext();

        // 1、获取 web.xml 中配置的上下文参数 context-param
        String username = context.getInitParameter("username");
        System.out.println("context-param 参数 username 的值是:" + username);
        System.out.println("context-param 参数 password 的值是:" + context.getInitParameter("password"));

    }
}

    <context-param>
        <param-name>username</param-name>
        <param-value>context</param-value>
    </context-param>
    <context-param>
        <param-name>password</param-name>
        <param-value>root</param-value>
    </context-param>

    <servlet>
        <servlet-name>ContextServlet</servlet-name>
        <servlet-class>com.atguigu.servlet.ContextServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>ContextServlet</servlet-name>
        <url-pattern>/contextServlet</url-pattern>
    </servlet-mapping>

运行结果及报错内容

部署后没有报错，也没有输出

我想要达到的结果

正确的输出应该如下：
context-param 参数 username 的值是:context
context-param 参数 password 的值是:root

用post请求调了吗