文章目录
springboot：各种下载文件的方式
一、使用response输出流下载
注意第一种方式返回值必须为void
@GetMapping("/t1")publicvoiddown1(HttpServletResponse response)throwsException{
response.reset();
response.setContentType("application/octet-stream;charset=utf-8");
response.setHeader("Content-disposition","attachment; filename=test.png");try(BufferedInputStream bis =newBufferedInputStream(newFileInputStream("E:\\desktop\\1.png"));// 输出流BufferedOutputStream bos =newBufferedOutputStream(response.getOutputStream());){byte[] buff =newbyte[1024];int len =0;while((len = bis.read(buff))>0){
bos.write(buff,0, len);}}}
二、使用ResponseEntity
@GetMapping("/t2")publicResponseEntity<InputStreamResource>down2()throwsException{InputStreamResource isr =newInputStreamResource(newFileInputStream("E:\\desktop\\1.png"));returnResponseEntity.ok().contentType(MediaType.APPLICATION_OCTET_STREAM).header("Content-disposition","attachment; filename=test1.png").body(isr);}@GetMapping("/t3")publicResponseEntity<ByteArrayResource>down3()throwsException{byte[] bytes =Files.readAllBytes(newFile("E:\\desktop\\1.png").toPath());ByteArrayResource bar =newByteArrayResource(bytes);returnResponseEntity.ok().contentType(MediaType.APPLICATION_OCTET_STREAM).header("Content-disposition","attachment; filename=test2.png").body(bar);}
三、注意
后端使用前三种的一种方式，请求方式使用非GET请求，前端使用Blob类型接收
某些情况下，在下载时需要向后端POST一些参数，这时需要前端做一定配合，将接收类型设定为Blob
@PostMapping("/t4")publicResponseEntity<ByteArrayResource>down4(String fileName,@RequestBodyMap data)throwsException{System.out.println(data);byte[] bytes =Files.readAllBytes(newFile("E:\\desktop\\1.png").toPath());ByteArrayResource bar =newByteArrayResource(bytes);returnResponseEntity.ok().contentType(MediaType.APPLICATION_OCTET_STREAM).header("Content-disposition","attachment; filename=test.png").body(bar);}
前端代码（这里使用了原生的ajax）:
<!DOCTYPEhtml><htmllang="en"><head><metacharset="UTF-8"><title>Title</title><script>functiondownload(){var ajax =newXMLHttpRequest();
ajax.withCredentials =true;
ajax.responseType ="blob";const fileName ="ttt.txt";
ajax.open('post','http://localhost:7901/demo/down/file/t4?fileName='+ fileName);
ajax.setRequestHeader("Content-Type","application/json;charset=utf-8");// ajax.setRequestHeader("Accept","application/json;charset=utf-8");
ajax.send(JSON.stringify({firstName:"Bill",lastName:"Gates",age:62,eyeColor:"blue"}));
ajax.onreadystatechange=function(){if(ajax.readyState==4&&ajax.status==200){
console.log(ajax.response);const href =URL.createObjectURL(ajax.response);const a = document.createElement('a');
a.setAttribute('href', href);
a.setAttribute('download', fileName);
a.click();URL.revokeObjectURL(href);}}}</script></head><body><inputtype="button"value="下载"onclick="download();"/></body></html>
本文转载自: https://blog.csdn.net/weixin_43296313/article/details/125100824
版权归原作者 yololee_ 所有， 如有侵权，请联系我们删除。
版权归原作者 yololee_ 所有， 如有侵权，请联系我们删除。