以下是一个比较完整的流程

后端代码如下：

controller：

@RequestMapping(value = "/download", method = RequestMethod.GET)public String downloadData(HttpServletResponse res) {    String data="这是一个下载文件";   //传入数据    File file=new File("文件.txt");    FileUtils.getFile(data.getBytes(),file.getName());    FileUtils.responseTo(file,res);    file.delete();    System.out.println("success");    return "success";}复制代码

工具类如下：

public class FileUtils {public static void getFile(byte[] bfile, String fileName) {    //创建文件    File file=new File(fileName);    try {        if (!file.exists()){file.createNewFile();}        FileOutputStream fos = new FileOutputStream(file);        fos.write(bfile);    } catch (Exception e) {        e.printStackTrace();    }}public static void responseTo(File file, HttpServletResponse res) {  //将文件发送到前端    res.setHeader("content-type", "application/octet-stream");    res.setContentType("application/octet-stream");    res.setHeader("Content-Disposition", "attachment;filename=" + file.getName());    byte[] buff = new byte[1024];    BufferedInputStream bis = null;    OutputStream os = null;    try {        os = res.getOutputStream();        bis = new BufferedInputStream(new FileInputStream(file));        int i = bis.read(buff);        while (i != -1) {            os.write(buff, 0, buff.length);            os.flush();            i = bis.read(buff);        }    } catch (IOException e) {        e.printStackTrace();    } finally {        if (bis != null) {            try {                bis.close();            } catch (IOException e) {                e.printStackTrace();            }        }    }    System.out.println("success");}}复制代码

前端文件接收：

axios({    url: '/gafzpt/capital/download',    method: 'get',    params: {      capitalId: capitalId    },    responseType: 'blob'     //接收类型设置，否者返回字符型  })    .then(res => {           //定义文件名等相关信息      const blob = res.data      const reader = new FileReader()      reader.readAsDataURL(blob)      reader.onload = (e) => {        const a = document.createElement('a')        a.download = `现金流文件`        a.href = e.target.result        document.body.appendChild(a)        a.click()        document.body.removeChild(a)      }    })复制代码