Java web项目从eclipse上移动到tomact服务器上，之路径更改，导出excel，jxl

我用的是jxl导出excel，比较简单，最开始我是固定路径不能选择，很局限，后来改了，而且固定路径当把项目放在服务器上时，路径不可行。

在网上各位大神的帮助成功设置响应头，并且可选保存路径。

1.前端

//不是用的ajax，好像ajax不能成功//js
$("#exportbaofei").click(function(){
                    window.location.href="${pageContext.request.contextPath}/ExportBaoFeiServlet";
 });
//html
<input type="button"  value="导出废模" id="exportbaofei"/>

2.servlet

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        log.info("导出报废模的servlet");
        MuJUService muJUService  = new MuJUService();
        //查询
        List<Map<String, String>>list =muJUService.exportBaoFei();
        //弹框选择路径
        WritableWorkbook book = null;
        response.reset();
        response.setCharacterEncoding("UTF-8");// 设置字符集
        // 创建工作流
        OutputStream os = null;
        try {
            // 设置弹出对话框
            response.setContentType("application/DOWLOAD");
            response.setCharacterEncoding("UTF-8");
            // 设置工作表的标题
            response.setHeader("Content-Disposition", "attachment; filename=feimu_month.xls");// 设置生成的文件名字、、不能用汉字，没有设置汉字解码
            os = response.getOutputStream();
            // 初始化工作表
            book = Workbook.createWorkbook(os);
        } catch (IOException e1) {

            log.error("导出excel出现IO异常", e1);
          //  throw new ServiceException("导出失败", e1);
            e1.printStackTrace();
        }

        //excel格式设置
        WritableFont font1= new WritableFont(WritableFont.createFont("楷体 _GB2312"), 12, WritableFont.NO_BOLD); //设置字体格式为excel支持的格式 WritableFont font3=new WritableFont(WritableFont.createFont("楷体 _GB2312"), 12, WritableFont.NO_BOLD);
        WritableCellFormat format1=new WritableCellFormat(font1);
        //把水平对齐方式指定为居中
        try {
            format1.setAlignment(jxl.format.Alignment.CENTRE);
            //把垂直对齐方式指定为居中
            format1.setVerticalAlignment(jxl.format.VerticalAlignment.CENTRE);
            //设置自动换行
            format1.setWrap(true);
        } catch (WriteException e1) {
            // TODO Auto-generated catch block
            log.error(e1);
            e1.printStackTrace();
        }

        // WritableWorkbook book = null;
            try {
                // 打开文件
               // book = Workbook.createWorkbook(new File(filename+".xls"));
                // 生成名为"学生"的工作表，参数0表示这是第一页
                WritableSheet sheet = book.createSheet("当月报废单", 0);

                sheet.addCell(new Label(0,0,"序号",format1));
                for(int i = 1;i<12;i++){
                    sheet.setColumnView(i,15);
                }
                sheet.addCell(new Label(1,0,"下单时间",format1));
                sheet.addCell(new Label(2,0,"返回时间",format1));
                sheet.addCell(new Label(3,0,"维修单号",format1));
                sheet.addCell(new Label(4,0,"产品图号",format1));
                sheet.addCell(new Label(5,0,"模具图号",format1));
                sheet.addCell(new Label(6,0,"模具规格",format1));
                sheet.addCell(new Label(7,0,"维修模号",format1));
                sheet.addCell(new Label(8,0,"维修数量",format1));
                sheet.addCell(new Label(9,0,"维修原因",format1));
                sheet.addCell(new Label(10,0,"报废模号",format1));
                sheet.addCell(new Label(11,0,"报废数量",format1));
                if(list!=null && !list.isEmpty()){
                    int rows =1;//hang
                    int cols = 0;//lie
                    for (Map<String, String> map : list) {
                        sheet.addCell(new Number(0, rows, rows));
                        sheet.addCell(new Label(1,rows,map.get("wx_xdan_data"),format1));
                        sheet.addCell(new Label(2,rows,map.get("wx_back_data"),format1));
                        sheet.addCell(new Label(3,rows,map.get("wx_danhao"),format1));
                        sheet.addCell(new Label(4,rows,map.get("wx_product_num"),format1));
                        sheet.addCell(new Label(5,rows,map.get("wx_mj_num"),format1));
                        sheet.addCell(new Label(6,rows,map.get("wx_mj_guige"),format1));
                        sheet.addCell(new Label(7,rows,map.get("wx_muhao"),format1));
                        sheet.addCell(new Label(8,rows,map.get("wx_count"),format1));
                        sheet.addCell(new Label(9,rows,map.get("wx_reason"),format1));
                        sheet.addCell(new Label(10,rows,map.get("wx_baofei_muhao"),format1));
                        sheet.addCell(new Label(11,rows,map.get("wx_baofei_count"),format1));
                        rows++;
                    }
                }
                book.write();

            } catch (Exception e) {
                log.error(e);
                System.out.println(e);
            }finally{
                if(book!=null){
                    try {
                        book.close();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }

    }