How to pass a object to be created as a parameter for a method in Java?

public void func(List<? extends base> list) { ... }

<form action="uploadFile" method="post"
                    enctype="multipart/form-data">
<input type="file" name="file" />
<input type="submit" value="Upload file" />

 <servlet>
    <servlet-name>UploadServlet</servlet-name>
    <servlet-class>package.UploadServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>UploadServlet</servlet-name>
    <url-pattern>/uploadFile</url-pattern>
</servlet-mapping>

protected void doPost(HttpServletRequest request, HttpServletResponse response) {
    yourMethod();
}

<form action="upload_file.jsp" method="post" enctype="multipart/form-data">

public static <R> R retry(Callable<R> action) {
    // Retry logic
    while(/* retry condition */) {
        action.call();
    }
}

Retry.retry(() -> a.fetchMax());
Retry.retry(() -> b.fetchPercentile(200));