Jakarta Standard Tag Library API basic tutorial (Fundamental Tutorial)

Jakarta Standard Tag Library (JSTL) API basic tutorial JSTL is a standard label library for the development of the Java server page (JSP).It provides a set of common labels and functions for JSP developers to simplify and accelerate the development process of the JSP page.This tutorial will introduce the basic concepts and usage of JSTL, and provide some practical Java code examples. 1 Overview Jstl is a set of label libraries developed by the Jakarta project.It provides a set of labels and functions used in the JSP page to achieve common logical operation and data processing.Using JSTL, developers can use functions such as cycle, conditional judgment, database access and internationalization on the JSP page. 2. Install jstl To start using JSTL, you need to download the JAR file of JSTL and add it to the class path of your Java Web application.You can get JSTL from the official website of the Jakarta project or using Maven and other construction tools. 3. The core tag of JSTL JSTL provides a set of commonly used tags through the core label library to process functions such as variables, cycle, conditional judgment and URL access.The following are examples of some core labels: (1) <c: set> label for setting the value of the variable: <c:set var="name" value="John" /> (2) <c: Foreach> Tags for circular processing collection: <c:forEach items="${users}" var="user"> <tr> <td>${user.name}</td> <td>${user.email}</td> </tr> </c:forEach> (3) <C: Choose> and <c: WHEN> labels for conditional judgment: <c:choose> <c:when test="${age < 18}"> <p>You are a minor.</p> </c:when> <c:otherwise> <p>You are an adult.</p> </c:otherwise> </c:choose> (4) <c: url> Tags are used to build a URL link: <a href="<c:url value='editUser.jsp'><c:param name='id' value='${user.id}' /></c:url>">Edit</a> 4. The formatting label of JSTL JSTL also provides a set of formatting labels for processing dates, numbers and internationalization.Here are some examples of formatting tags: (1) <FMT: Formatdate> Tags for formatting date: <fmt:formatDate value="${user.birthdate}" pattern="yyyy-MM-dd" /> (2) <fmt: Formatnumber> Tags are used for formatting numbers: <fmt:formatNumber value="${price}" type="currency" /> (3) <fmt: setlocale> labels to set localized language: <fmt:setLocale value="zh_CN" /> 5 Conclusion This tutorial introduces the basic concepts and usage of JSTL.It is a very useful tool that can accelerate the development process of the JSP page and provide many common feature labels and functions.By learning and using JSTL, developers can create strong and easy -to -maintain JSP applications. I hope this tutorial will help you understand JSTL and provide help.If you have any questions, please ask at any time.