后端

public class EasyExcelUtil {
    //导出Excel
    public void exproExcel(HttpServletResponse response, List<?> data, String fileName, String sheetName, Class<? extends BaseRowModel> cls){
        try {
            response.reset();
            OutputStream output = response.getOutputStream();
            BufferedOutputStream bufferedOutput = new BufferedOutputStream(output);
                EasyExcel.write(bufferedOutput)
                        .head(cls)
                        .autoCloseStream(true)
                        .excelType(ExcelTypeEnum.XLSX)
                        .sheet(sheetName)
                        .doWrite(data);
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=UTF-8");
            response.setHeader("Content-Disposition", "attachment;filename="+ URLEncoder.encode(fileName,"UTF-8")+".xlsx");
            response.setHeader("Access-Control-Expose-Headers","FileName");
            response.setHeader("FileName",URLEncoder.encode(fileName,"UTF-8"));


        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

前端

//封装请求
                    function getDownload() {
                        // xhr.setRequestHeader("Content-type","application/x-www-form-urlencoded");
                        var customerId = self.customerId;
                        let day = moment().format('YYYY-MM-DD');
                        const  token = getValueFromLocalStorage("token");
                        const url = cb.router.HTTP_CHECK_INFO+"?customerId="+customerId+"&day="+day;
                        var xhr = new XMLHttpRequest();
                        xhr.open('GET', url, true);
                        xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");       
                        xhr.responseType = "blob";
                        xhr.setRequestHeader("token",token);
                            
                
                        // 定义请求完成的处理函数，请求前也可以增加加载框/禁用下载按钮逻辑
                        xhr.onload = function () {
                            // 请求完成
                            if (this.status === 200) {
                                var data = this.response;
                                const fileName = "对账申请单.xlsx";
                                //解决乱码问题
                                const blob = new Blob(["\uFEFF",data],{type:'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8'});
                                // const blob = new Blob([data]);
                                // 创建一个a标签用于下载
                                console.log(blob);
                                var a = document.createElement('a');
                                let objectUrl = window.URL.createObjectURL(data)
                                a.href = objectUrl;
                                a.download = fileName;
                                a.style.display = 'none';   
                                a.setAttribute('download',fileName);   
                                //启动a标签点击事件下载
                                a.click();
                                $(a).remove(); // 下载完成移除元素
                                window.URL.revokeObjectURL(objectUrl)    // 释放掉blob对象
                            }
                        };
                        // 发送ajax请求
                        xhr.send()
                    }

上面代码没有任何问题在导出Ecxel的时候出现乱码问题

QQ图片20201117104536.jpg

排查问题最后找到是因为mock.js文件原因，每次执行这个JS文件会拦截请求，造成乱码的情况注释掉就好了(你奶奶个腿)

QQ图片20201117104628.png

QQ图片20201117104840.png

恢复正常~