在页面中显示EXCEL报表

<%@ page language="java" contentType="application/vnd.ms-excel; charset=gbk" pageEncoding="gbk"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Insert title here</title>
</head>
<body>
<%@ page import="net.sf.jasperreports.engine.*" %>
    <%@ page import="java.util.*" %>
    <%@ page import="java.io.*" %>
    <%@ page import="java.sql.*" %>
    <%@ page import="net.sf.jasperreports.engine.util.*" %>
    <%@ page import="net.sf.jasperreports.engine.export.*" %>
<%
    File reportFile = new File(application.getRealPath("report/employee.jasper"));
    Connection conn =null ;
    String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=as";
    String driver="com.microsoft.jdbc.sqlserver.SQLServerDriver";
    try{
    Class.forName(driver);
    conn = DriverManager.getConnection(url,"test","test");    
    Map parameters = new HashMap();
//String str=JasperRunManager.runReportToHtmlFile(reportFile.getPath(),parameters,conn); 
//String str=JasperRunManager.runReportToHtmlFile(reportFile.getPath(),parameters,new JREmptyDataSource());
//System.out.println(str);
parameters.put("employeeId", new String("1001011"));
//生成EXCEL
JasperPrint jasperPrint = JasperFillManager.fillReport(reportFile.getPath(),parameters,conn);    JRXlsExporter exporter = new JRXlsExporter(); 
    
    exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
    //exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, response.getOutputStream());
    exporter.setParameter(JRXlsExporterParameter.IS_REMOVE_EMPTY_SPACE_BETWEEN_ROWS,Boolean.TRUE); // 删除记录最下面的空行
     exporter.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET,Boolean.FALSE);// 删除多余的ColumnHeader
    exporter.setParameter(JRXlsExporterParameter.IS_WHITE_PAGE_BACKGROUND,Boolean.FALSE);// 显示边框
     exporter.exportReport(); response.setContentType("application/vnd.ms-excel");
conn.close();

    }catch(Exception e){
     e.printStackTrace();
    }
   %>
</body>
</html>一运行就提示保存...怎么让他在页面中显示EXCLE预览?