ajax导出excel

ajax 是无法直接导出excel的,因为ajax返回值只能是字符流,而导出excel是后台往浏览器中写入二进制的字节流

• 浏览器弹窗下载excel文件

//response设置头文件
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
//导出excel其实就是后台给浏览器写入字节流
Workbook excel = new XSSFWorkbook();
....省略写入数据代码
excel.write(outputStream);     
outputStream.flush();                
outputStream.close();               

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导出excel方法:

• 方法一:window.open() & form表单.submit().

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• 方法二:ajax请求把参数缓存在后端返回给前端key,前端ajax再次发起一个window.open(url?key=key)即可,详细代码如下:

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JS代码

$.ajax({
url: '../../eldercare/excel/export?_' + $.now(),
type: 'post',
dataType: "json",
contentType : 'application/json',
data : JSON.stringify(this.tableOpts),
success: function(data){
    window.open('../../eldercare/excel/downFromCache?key='+data.rows, '_self');
},

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java代码

    /**
     * 由于ajax无法直接导出excel,所以第一次把请求生成的ExcelParam缓存起来,然后前端再次window.open(url);
     */
    public static Map<String, ExcelParam> excelParamCache = new ConcurrentHashMap<>();

    //第一步缓存参数
    @SuppressWarnings("unchecked")
    @RequestMapping(value = "/export")
    @ResponseBody
    public R export(@RequestBody ExcelParam excelParam) {
        Assert.notNull(excelParam,"参数不能为空");
        Assert.notNull(excelParam.getUrl(),"url参数不能为空");
        Assert.notNull(excelParam.getColumns(),"columns参数不能为空");
        Assert.notNull(excelParam.getFileName(),"fileName参数不能为空");
        String key = UUID.randomUUID().toString();
        excelParamCache.put(key,excelParam);
        return CommonUtils.msg(key);
    }

    //第二步下载文件
    @RequestMapping(value = "/downFromCache", method = RequestMethod.GET)
    public void downFromCache(String key,HttpServletRequest request, HttpServletResponse response) {
        try {
            Assert.hasText(key,"key不能为空");
            ExcelParam excelParam = excelParamCache.get(key);
            excelService.reflexList(excelParam);
            excelService.export(excelParam,request,response);
        } catch (Exception e) {
            e.printStackTrace();
            excelParamCache.remove(key);
        } finally {
            excelParamCache.remove(key);
        }
    }