Introduction to the use of jstl tags

Import Jstl tag library

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

Need to import jstl.jar and standard.jar

c:forEach --> Iterate labels to iterate List or Map

<c:forEach var="person" items="${list}">
${person.name}</br>
</c:forEach>

<c:foreach var="entry" items="${map }"> Iterate over the set collection returned by map.entrySet()
${entry.key } : ${entry.value }
</c:foreach>

<c:forEach var="num" begin="1" end="9" step="1">
${num}
</c:forEach>

<!-- ${status} obtains an object, which contains the current iteration -->
<c:forEach var="str" ​​items="${list }" varStatus="status">
<tr>
</c:forEach>

c:if --> Determine label
<c:if test="${user!=null}" var="result"> If user exists, result will be true
Welcome:${user.username}
</c:if>
${result}

c:out

<c:out value="${data }" default="aaaaa" escapeXml="true"></c:out>

c:set

<!-- c:set can operate the javabean Map collection of each domain-->
<c:set var="data" value="xxxxxx" scope="page"></c:set>Change the value of data;

<c:set property="propertyname" value="valuexx" target="${map }"></c:set>
${map.propertyname}

<c:set property="name" value="uuuuuu" target="${person }"></c:set>
${p.name}

c:catch

<c:catch var="ex">
<%
int x = 1 / 0;
%>
</c:catch>
${ex.message}

c:forTokens --> Split tags

<c:forTokens var="ss" items="${data1 }" delims=",">
${ss}
</c:forTokens>
data1={"a,b,c,d"}

c:url --> Generate URL

<c:url var="uurrll" value="/example/ind1ex.jsp">
<c:param name="namechina" value="China"></c:param>
</c:url>
<a href="${uurrll }">hreftext</a>