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();
}
}
}
}