Jquery上传
jquery文件时，后端好像并没有经过SpringMVC处理，没有被封装成一个MultiPartFIle对象，可通过原生的Servlet API request.getInputStream()获取。至于为什么没被SpringMVC封装成MultipartFile对象目前还没有研究透彻。可能是请求内容类型没有设置成 multipart/form-data。下面是jquery上传文件的代码示例，文件名，文件大小等参数可通过拼在url后面使用request.getParameter()获取。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<script src="jquery.js"></script>
<script src="axios.js"></script>
<body>
请上传图片：<input type="file" name="file" id="file" onchange="fileChange(this)">
<br>
<button onclick="jqueryUpload()">jquery提交</button>
</body>
<script>
var file = undefined
function fileChange(data){
file = data.files[0]
}
function jqueryUpload(){
$.ajax({
url:"/jqueryUpload?filename=test.jpg",
type:"post",
data:file,
contentType:false,
processData:false,
success(res){
console.log('上传结果' + res)
}
})
}
</script>
</html>
@PostMapping("jqueryUpload")
public String jqueryUpload(HttpServletRequest request, MultipartFile file) throws Exception{
System.out.println(file);
String fileDesc = "D:\\2022\\" + request.getParameter("filename");
FileOutputStream outputStream = new FileOutputStream(fileDesc);
ServletInputStream inputStream = request.getInputStream();
byte[] bytes = new byte[1024];
int line = inputStream.read(bytes);
while (line != -1){
outputStream.write(bytes,0,line);
line = inputStream.read(bytes);
}
inputStream.close();
outputStream.close();
return "success";
}
此时后台打印的multipartfile是null。后续会深入研究·······…
Axios上传
axios上传不同于jquery，axios将上传的二进制数据和其他参数封装在了FormData对象中，值得注意的是，此时的内容类型要改为multipart/form-data。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<script src="jquery.js"></script>
<script src="axios.js"></script>
<body>
请上传图片：<input type="file" name="file" id="file" onchange="fileChange(this)">
<br>
<button onclick="jqueryUpload()">jquery提交</button>
<button onclick="axiosUpload()">axios提交</button>
</body>
<script>
var file = undefined
function fileChange(data){
file = data.files[0]
}
function axiosUpload(){
var formData = new FormData();
formData.append("file",file);
formData.append("filename","myfile.jpg")
axios.post("/axiosUpload",formData,{
headers:{ "Content-Type" : "multipart/form-data" }
}).then(res => {
console.log('上传结果' + res)
})
}
</script>
</html>
@PostMapping("axiosUpload")
public String axiosUpload(HttpServletRequest request,MultipartFile file)throws Exception{
InputStream inputStream = file.getInputStream();
String fileDesc = "D:\\2022\\" + request.getParameter("filename");
FileOutputStream os = new FileOutputStream(fileDesc);
byte[] bytes = new byte[1024];
int line = inputStream.read(bytes);
while (line != -1){
os.write(bytes,0,line);
line = inputStream.read(bytes);
}
inputStream.close();
os.close();
return "success";
}
感觉还是更喜欢axios这种，明确指定了内容类型并且经过了SpringMVC处理。