目录 一、使用response输出流下载 二、使用ResponseEntity 三、注意 总结 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") public void down1(HttpServletResponse response) thr
目录
- 一、使用response输出流下载
- 二、使用ResponseEntity
- 三、注意
- 总结
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")
public void down1(HttpServletResponse response) throws Exception {
response.reset();
response.setContentType("application/octet-stream;charset=utf-8");
response.setHeader(
"Content-disposition",
"attachment; filename=test.png");
try(
BufferedInputStream bis = new BufferedInputStream(new FileInputStream("E:\\desktop\\1.png"));
// 输出流
BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream());
){
byte[] buff = new byte[1024];
int len = 0;
while ((len = bis.read(buff)) > 0) {
bos.write(buff, 0, len);
}
}
}
二、使用ResponseEntity
@GetMapping("/t2")
public ResponseEntity<InputStreamResource> down2() throws Exception {
InputStreamResource isr = new InputStreamResource(new FileInputStream("E:\\desktop\\1.png"));
return ResponseEntity.ok()
.contentType(MediaType.APPLICATION_OCTET_STREAM)
.header("Content-disposition", "attachment; filename=test1.png")
.body(isr);
}
@GetMapping("/t3")
public ResponseEntity<ByteArrayResource> down3() throws Exception {
byte[] bytes = Files.readAllBytes(new File("E:\\desktop\\1.png").toPath());
ByteArrayResource bar = new ByteArrayResource(bytes);
return ResponseEntity.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")
public ResponseEntity<ByteArrayResource> down4(String fileName, @RequestBody Map data) throws Exception {
System.out.println(data);
byte[] bytes = Files.readAllBytes(new File("E:\\desktop\\1.png").toPath());
ByteArrayResource bar = new ByteArrayResource(bytes);
return ResponseEntity.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）:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script>
function download() {
var ajax = new XMLHttpRequest();
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>
<input type="button" value="下载" onclick="download();"/>
</body>
</html>
总结
到此这篇关于springboot各种下载文件的文章就介绍到这了,更多相关springboot下载文件内容请搜索自由互联以前的文章或继续浏览下面的相关文章希望大家以后多多支持自由互联！