<%@ page contentType="text/html; charset=utf-8" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %>
    ...
    <div class="jumbotron">
        <div class="container">
            <h1 class="display-3">도서 등록</h1>
        </div>
    </div>

    <div class="container">
        <div class="float-right">

➊

            <form:form action="${pageContext.request.contextPath}/logout" method="POST">
                <input type="submit" class="btn btn-sm btn-success" value="Logout"/>
            </form:form>

        </div>
        <br><br>
        <form:form modelAttribute="NewBook" class="form-horizontal">
...