public ActionForward list(ActionMapping mapping, ActionForm form,   
            HttpServletRequest request, HttpServletResponse response)   
            throws Exception {   
        JbpmConfiguration configuration = Utils.configuration;   
        JbpmContext jbpmContext = configuration.createJbpmContext();   
        String userName = (String) request.getSession()   
                .getAttribute("userName");   
        try {   
            TaskMgmtSession taskMgmtSession = jbpmContext.getTaskMgmtSession();   
            List list = taskMgmtSession.findPooledTaskInstances(userName);   
            request.setAttribute("list", list);   
            return mapping.findForward("list");   
        } finally {   
            jbpmContext.close();//在这里把上下文关闭掉了,引起了页面出错          
}   
    }  

 <table>   
    <tr>   
        <td>报销单ID</td>   
        <td>环节名称</td>   
        <td>建立时间</td>   
        <td>操作</td>   
    </tr>   
    <logic:iterate id="task" scope="request" name="list">   
    <tr>   
        <td><%=((TaskInstance) task).getVariable("baoxiaoId") %></td>//由于 variableInstances对象延迟加载,在取得变量的时候出错了    
<td>${task.name}</td>   
        <td>${task.create}</td>   
        <td><input type="button" taskid="${task.id}" value="同意" onclick="agree(this.taskid);" /><input type="button" taskid="${task.id}" value="不同意" onclick="disagree(this.taskid);" /></td>   
    </tr>   
    </logic:iterate>   
  </table>