1.情景展示
<table style="order-collapse: collapse;" cellspacing="0" cellpadding="1" border="0" width="99%">
<tbody>
<tr class="TableHeader" align="center">
<td class="TableHeaderCell" nowrap="nowrap">日期</td>
<td class="TableHeaderCell" nowrap="nowrap">线上正式卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线上临时卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线下正式卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线下临时卡</td>
</tr>
<c:forEach var="card" items="${model.data}">
<tr class="TableRow" align="center">
<td nowrap="nowrap" class="TableCell" align="left">${card.REGTIME}</td>
<td nowrap="nowrap" class="TableCell" align="left">${card.ONLINE_FORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${card.ONLINE_INFORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${card.OFFLINE_FORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${card.OFFLINE_INFORMAL}</td>
</tr>
</c:forEach>
</tbody>
</table>
如上图所示，在使用c:foreach标签迭代完毕后，需要加一行合计，对每列数据进行求和，如何实现？
2.思路分析
foreach标签起到Java里for循环的作用；
set标签可以用于声明变量或者变量赋值；
EL表达式支持各种数值运算和字符串函数。
3.解决方案
<table style="order-collapse: collapse;" cellspacing="0" cellpadding="1" border="0" width="99%">
<tbody>
<tr class="TableHeader" align="center">
<td class="TableHeaderCell" nowrap="nowrap">日期</td>
<td class="TableHeaderCell" nowrap="nowrap">线上正式卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线上临时卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线下正式卡</td>
<td class="TableHeaderCell" nowrap="nowrap">线下临时卡</td>
</tr>
<c:forEach var="card" items="${model.data}">
<tr class="TableRow" align="center">
<td nowrap="nowrap" class="TableCell" align="left">${card.REGTIME}</td>
<td nowrap="nowrap" class="TableCell" align="left">
${card.ONLINE_FORMAL}
<c:set var="SUM_ONLINE_FORMAL" value="${SUM_ONLINE_FORMAL + card.ONLINE_FORMAL}"/>
</td>
<td nowrap="nowrap" class="TableCell" align="left">
${card.ONLINE_INFORMAL}
<c:set var="SUM_ONLINE_INFORMAL" value="${SUM_ONLINE_INFORMAL + card.ONLINE_INFORMAL}"/>
</td>
<td nowrap="nowrap" class="TableCell" align="left">
${card.OFFLINE_FORMAL}
<c:set var="SUM_OFFLINE_FORMAL" value="${SUM_OFFLINE_FORMAL + card.OFFLINE_FORMAL}"/>
</td>
<td nowrap="nowrap" class="TableCell" align="left">
${card.OFFLINE_INFORMAL}
<c:set var="SUM_OFFLINE_INFORMAL" value="${SUM_OFFLINE_INFORMAL + card.OFFLINE_INFORMAL}"/>
</td>
</tr>
</c:forEach>
<tr class="TableRow" align="center">
<td nowrap="nowrap" class="TableCell" align="left">合计</td>
<td nowrap="nowrap" class="TableCell" align="left">${SUM_ONLINE_FORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${SUM_ONLINE_INFORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${SUM_OFFLINE_FORMAL}</td>
<td nowrap="nowrap" class="TableCell" align="left">${SUM_OFFLINE_INFORMAL}</td>
</tr>
</tbody>
</table>