spring boot实现文件的下载

在前端页面，html中JavaScript脚本的定义如下：

function exportFile(){
       var form=$("<form>");
       form.attr("style","display:none");
       form.attr("target","");
       form.attr("method","post");//提交方式为post
       form.attr("action","/downloadFile");//定义action

       $("body").append(form);
       form.submit();
   }

在Spring boot中的Controller类中创建一个方法downloadFile,方法体的定义如下：

@RequestMapping("/downloadFile")

private String downloadFile(HttpServletResponse response){
       String downloadFilePath = "/root/fileSavePath/";//被下载的文件在服务器中的路径,
       String fileName = "demo.xml";//被下载文件的名称

       File file = new File(downloadFilePath);
if (file.exists()) {
   response.setContentType("application/force-download");// 设置强制下载不打开
response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);
byte[] buffer = new byte[1024];
FileInputStream fis = null;
BufferedInputStream bis = null;
try {
fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
OutputStream outputStream = response.getOutputStream();
int i = bis.read(buffer);
while (i != -1) {
outputStream.write(buffer, 0, i);
i = bis.read(buffer);
}

return "下载成功";
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
       return "下载失败";
   }

在前端页面点击“下载文件”按键后 spring boot实现文件的下载，

会自动弹出下载文件的对话框，效果图如下：

spring boot实现文件的下载