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>