在servlet里面:
List<ShowBean> l= conns.getuser(dostr);
for(int i=0;i<l.size();i++) {
ShowBean bean=(ShowBean)l.get(i);
System.out.println(bean.getId());
System.out.println(bean.getUsername());
System.out.println(bean.getPsw());
}
request.setAttribute("users", l);
request.getRequestDispatcher("/showuser.jsp").forward(request,response);
返回一个list到jsp上面
然后在jsp就不懂怎么显示啦@!!!求解啊!!
我试过的方法:
List<ShowBean> list=(List)request.getAttribute("users");
ShowBean bean=new ShowBean();
for(int i=0;i<list.size();i++)
{
bean=list.get(i);
}Showbean是一个实体类。在jsp上面用<%@ page import= "mybean.ShowBean"%> 引入 这样有问题吗??
List<ShowBean> l= conns.getuser(dostr);
for(int i=0;i<l.size();i++) {
ShowBean bean=(ShowBean)l.get(i);
System.out.println(bean.getId());
System.out.println(bean.getUsername());
System.out.println(bean.getPsw());
}
request.setAttribute("users", l);
request.getRequestDispatcher("/showuser.jsp").forward(request,response);
返回一个list到jsp上面
然后在jsp就不懂怎么显示啦@!!!求解啊!!
我试过的方法:
List<ShowBean> list=(List)request.getAttribute("users");
ShowBean bean=new ShowBean();
for(int i=0;i<list.size();i++)
{
bean=list.get(i);
}Showbean是一个实体类。在jsp上面用<%@ page import= "mybean.ShowBean"%> 引入 这样有问题吗??
<%
List<ShowBean> list=(List)request.getAttribute("users");
for(int i=0;i<list.size();i++) {
ShowBean bean = (ShowBean) list.get(i);
out.write(bean.getXXOO());
}
%>
如果要得到serlet的值就${l}或者request.getAttribute("l")
错误信息是:
严重: Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException: ShowBean
at org.apache.jsp.showuser_jsp._jspService(showuser_jsp.java:108)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
是不是ShowBean实体类有什么问题,或者在jsp里面导入得不对
<%@ page import= "mybean.*"%>
<%
List list=(List)request.getAttribute("users");
for(int i=0;i<list.size();i++) {
Object bean = list.get(i);
System.out.println(bean.getClass());
}
%>看看是啥?另外如果是JSP2.0的话,可以用EL表达式:
<c:forEach items="users" var="obj">
${obj.XXOO}
</c:forEach>
for(User user:users){%>
<%=user %>
<%}
%>
这样已经很简单了
<c:foreach items="${users}" var="obj">
${obj.XXOO}
</c:foreach>
</c:if>
<c:foreach items="${users}" var="obj"> 前面有个黄色的三角叹号!上面显示的消息是:Unkonw tag (c:foreach)
你就没有引入jstl标签库。你要问怎么引入是吧。百度。
<table>
<tr>
<th>id</th>
<th>username</th>
<th>psw</th>
</tr>
<%
List<ShowBean> list=(List)request.getAttribute("users");
for(int i=0;i<list.size();i++){
%>
<tr>
<th><%=list.get(i).getId()%></th>
<th><%=list.get(i).getUsername()%></th>
<th><%=list.get(i).getPsw()%></th>
</tr>
<%
}
%>
</table>
<%
List<ShowBean> list=(List)request.getAttribute("users");
if(list!=null){
for(int i=0;i<list.size();i++) {
ShowBean bean = (ShowBean) list.get(i);
%>
<table>
<tr>
<td>
<%=bean.getId()%>
</td>
<td>
<%=bean.getUsername()%>
</td>
<td>
<%=bean.getPsw()%>
</td>
</tr>
</table> <%
}
}else{
%>
DB没数据!!
<%
}%>