jstl应用实例

1.抓取url中的id值
例如: http://localhost:8080/qas/delete_question.html?qid=4


<input type="hidden" name="qid" value="${param.qid}"/>

2.选定默认radio


<s:iterator value="satisfctions">


<td>


<input name="satify_id" type="radio" <s:if test="${question.satisfaction.id==id}">checked</s:if> value="<s:property value="id"/>"><s:property value="name"/></input>


</td>


</s:iterator>

3. 逻辑标签


<c:if test="${msg!='没有查到该用户'}">


<tr>


<td colspan="2" align="center"><input type="submit" onclick="return isRemit();" value="确定"/></td>


</tr>
注意要加单引号''，因为标签取出的东东都是字符串。


</c:if>
<c:if test="${realAnswer== '1 '}" >是 </c:if >
<c:if test="${realAnswer== '2 '}" >不是 </c:if >
<c:if test="${realAnswer!= '1 ' && realAnswer!= '2 '}" >${realAnswer}
</c:if >

4.得到项目根目录。




$...{pageContext.request.contextPath}




<script language="javascript" src="${pageContext.request.contextPath}/prototype.js"></script>



5.遍历


<c:forEach var="coursePart" items="${courseParts}">


<tr class="tablehead">




<td>$...{coursePart.id}</td>




<td>$...{coursePart.name}</td>




<td>$...{coursePart.course.name}</td>


<td>


<a href="increaseDown.html?coursePartId=${coursePart.id}">下载</a>


</td>


<td>


<a href="increaseHitsOnline.html?coursePartId=${coursePart.id}">查看</a>


</td>


</tr>


</c:forEach>

6.判断为null




<c:if test="${question.answer!=null}">$...{question.answer}</c:if>

7.带序号遍历


<c:forEach var="subject" items="${subjects}" varStatus="i">




<a href="#" onclick="link_clicked('${i.index}')">$...{subject.name}</a> |


</c:forEach>

8.嵌套遍历


<c:forEach var="subject" items="${subjects}" varStatus="i">


<div id="sub_nav${i.index}" class="head-sub-nav" style="display: none;">


<c:forEach var="book" items="${subject.books}" varStatus="j">




<a href="#" onclick="link_clicked2(${i.index},${j.index});">$...{book.name}</a> |


</c:forEach>


</div>


</c:forEach>

9.forEach与set混合应用


<td>


<c:set var="isRightNum" value="0"/>


<c:forEach var="questionHistory" items="${examnationHistory.questionsHistorys}">


<c:if test="${questionHistory.isRight == 0}">


<c:set var="isRightNum" value="${isRightNum +1}"/>


</c:if>


</c:forEach>




$...{isRightNum }个


</td>

10．截取字符串

${fn:substring(cityDay.date,"0","10")}

11. 嵌套循环，例如遍历树形结构,

CateService cateService = (CateService)ctx.getBean("catesService");
List cates =  cateService.getBaseCatesByCityId(Integer.parseInt(city));
List allcates = new ArrayList();
for(int i= 0;i<cates.size();i++){
TtCate cate = (TtCate)cates.get(i);
Integer cid = cate.getId();
List subCates = cateService.getCatesByPid(cid);
ObjectListBean olb = new ObjectListBean();
olb.setObj(cate);
olb.setList(subCates);
allcates.add(olb);
}

request.setAttribute("allcates", allcates);

其中

package com.secondhand.common;
import java.io.Serializable;
import java.util.List;
public class ObjectListBean implements Serializable {
private Object obj;
private List list;
public ObjectListBean() {
}
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public Object getObj() {
return obj;
}
public void setObj(Object obj) {
this.obj = obj;
}
}

页面遍历

<tr>
<c:set var="num" value="0"/>
<c:forEach var="cc" items="${allcates}">
<c:set var="num" value="${num+1}"/>
<td width="191" valign="top"><table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td height="17" background="images/lm-bj_34.jpg"><a href="sort.php?city=beijing&sortid=8" mce_href="sort.php?city=beijing&sortid=8"><span class=" txt_14bt">${cc.obj.name }</span></a></td>
<td width="1" rowspan="3" background="images/sxx_36.jpg"></td>
</tr>
<tr>
<td height="10"></td>
</tr>
<tr>
<td><table width="100%" border="0" cellspacing="0" cellpadding="0">
<c:forEach var="subcc" items="${cc.list}">
<tr>
<td width="24" align="center"><img src="images/jj_42.jpg" mce_src="images/jj_42.jpg" width="8" height="5" /></td>
<td height="25" class="txt_13"><a href="infolist_beijing_8_37" mce_href="infolist_beijing_8_37"> ${subcc.name }</a><span class="txt_hui">(3652264)</span></td>
</tr>
</c:forEach>
</table></td>
</tr>
<tr>
<td height="17"> </td>
<td width="1"></td>
</tr>
</table></td>
<c:if test="${num mod 4 == 0}">
</tr>
<tr>
</c:if>
</c:forEach>
</tr>