发神经了，暴了一个org.apache.jasper.JasperException解决思路

package com.gz.koal.sys.tag;import java.io.IOException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.TagSupport;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import com.gz.koal.model.Useres;import com.opensymphony.xwork.DefaultActionInvocation;/** * 工具栏标签 * @author Administrator * */public class ToolTag extends TagSupport {    private static final long serialVersionUID = 1L;    private static final Log LOG = LogFactory.getLog(DefaultActionInvocation.class);        private Useres user=null;    public static long getSerialVersionUID() {                return serialVersionUID;    }    public Useres getUser() {        return user;    }    public void setUser(Useres user) {        this.user = user;    }        public int doStartTag()  {        JspWriter out=this.pageContext.getOut();        try {                        out.println("<div  align='right' style='background: #dfdddd'>");            if(user==null)            {                out.println("<a href='/webwork/jsp/login.jsp' target='_parent'>[登录]</a> ");                out.println("<a href='/webwork/jsp/register.jsp' target='_parent'>[注册]</a> ");                                            }else            {                                   out.println("<a href='/webwork/jsp/control.jsp' target='_parent'>["+user.getUserName()+"]设置</a>");                out.println("<a href='/webwork/user!undo.action'>[注销]</a> ");            }            out.println("<a href='/webwork/jsp/index.jsp' target='_parent'>[返回主页]</a>");            out.println("</div><br/>");                  } catch (IOException e) {            LOG.error("标签文件发生IO流异常"+e.getMessage());                    }catch(Exception e)        {            LOG.error("标签文件发生未知异常"+e.getMessage());        }        return SKIP_BODY;    }        }