Java JSTL 计算 ForEach 循环
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JSTL Count the ForEach loop
提问by Reddy
I am trying to print some message for every 4 items in the List of items
我正在尝试为项目列表中的每 4 个项目打印一些消息
<c:forEach items="${categoryList}" var="category" varStatus="i">
<c:if test="${i%4 == 0}">
<c:out value="Test" />
</c:if>
<div class="span3">
<c:out value="a" />
</div>
</c:forEach>
But I am getting below exceptions, seems like iis not treated as number
但是我遇到了例外情况，似乎i没有被视为数字
java.lang.IllegalArgumentException: Cannot convert javax.servlet.jsp.jstl.core.LoopTagSupportStatus@3371b822 of type class javax.servlet.jsp.jstl.core.LoopTagSupportStatus to Number
at org.apache.el.lang.ELArithmetic.coerce(ELArithmetic.java:407)
at org.apache.el.lang.ELArithmetic.mod(ELArithmetic.java:291)
at org.apache.el.parser.AstMod.getValue(AstMod.java:41)
at org.apache.el.parser.AstEqual.getValue(AstEqual.java:38)
How do I achieve this?
我如何实现这一目标？
One way is to declare a variable and increment for every loop with the help of scriplets. But I would like to avoid this!
一种方法是在脚本的帮助下为每个循环声明一个变量和增量。但我想避免这种情况！
采纳答案by Rohit Jain
The variable iis of type LoopTagStatus. To get an int, you can use getCount()or getIndex().
变量i的类型为LoopTagStatus。要获得int，您可以使用getCount()或getIndex()。
If you want to print message for 1stitem, then use:
如果您想打印消息1日项目，然后使用：
<!-- `${i.index}` starts counting at 0 -->
<c:if test="${i.index % 4 == 0}">
<c:out value="Test" />
</c:if>
else use:
否则使用：
<!-- `${i.count}` starts counting at 1 -->
<c:if test="${i.count % 4 == 0}">
<c:out value="Test" />
</c:if>
