c:if与s:if的基本使用

1.使用s:if判断字符串

<s:if test='a!="ah"'>
		table0
	</s:if>

2.s:if判断null

<s:if test="list!=null && list.size!=0">
	<table border="1">
		<tr><td>table1</td><tr>
			<s:iterator value="list" id="u" status="st">
				<tr>
					<td><s:property value="#st.index" /></td>
					<td> <s:property value="[color=red]#u.id[/color]"/></td>
					<td> <s:property value="[color=red]username[/color]"/></td>
					<td> <s:property value="password"/></td>
				<tr>
			</s:iterator>
	</table>
	</s:if>

3.c:if判断是否为null

<c:if test="${!empty list}">	<table border="1">
	<tr><td colspan="3">table2</td><tr>
	<c:forEach var="u" items="${list}" varStatus="sta">
                <tr>
                   <td>${sta.index}</td>
                   <td align="center"> ${u.id} </td>
                   <td align="center"> ${u.username } </td>
                   <td align="center"> ${u.password} </td>
                </tr>
    </c:forEach>
    </table>
   </c:if>