JSP文件上传返回空的输入流以进行文件上传

发布于 2025-01-21 11:01:55 字数 958 浏览 0 评论 0原文

我正在使用AJAX调用进行JSP文件上传，并且能够在HttpservletRequest中击中Java控制器，我会看到收到的Multipart文件，但是当我进行request.getInputStream.getInputStream.readallBytes（）时，我得到了一个空字节数组

JavaScript中的Ajax调用

function saveFileUpload() {
    var data = new FormData()
    data.append("file", document.getElementById(fileName).files[0])

    $.ajax({
        type: 'POST',
        data: data,
        url: pageContext + "/upload",
        processData: false,
        contentType: false,
        success: function(data) {},
        error: function(e) {}
    });

  }
}

在Java控制器中的

    @RequestMapping(value = {"/upload"}, method = RequestMethod.POST)
    public void fileUpload (
            HttpServletRequest request, HttpServletResponse response){
        byte[] arr = request.getInputStream().readAllBytes();
        System.out.println(arr.length);
    }

上述代码prints arr.length为0。有人可以告诉我这个问题的原因吗？

原文

I am working on a jsp file upload using ajax call and I am able to hit the java controller in the HttpServletRequest I see the multipart file received but when I do request.getInputStream.readAllBytes(), I get an empty byte array

The ajax call in javascript

function saveFileUpload() {
    var data = new FormData()
    data.append("file", document.getElementById(fileName).files[0])

    $.ajax({
        type: 'POST',
        data: data,
        url: pageContext + "/upload",
        processData: false,
        contentType: false,
        success: function(data) {},
        error: function(e) {}
    });

  }
}

In Java controller

    @RequestMapping(value = {"/upload"}, method = RequestMethod.POST)
    public void fileUpload (
            HttpServletRequest request, HttpServletResponse response){
        byte[] arr = request.getInputStream().readAllBytes();
        System.out.println(arr.length);
    }

The above code prints arr.length as 0. Can someone tell me the reason for this issue?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

红衣飘飘貌似仙 2025-01-28 11:01:55

我假设您正在使用springboot，并且您的应用程序支持multipart/form-data。版本 3.0 Servlet API本身支持它。

@RequestMapping(value = "/upload", method = RequestMethod.POST)
public void fileUpload(@RequestParam("file") MultipartFile file) throws IOException 
{
    if (!file.isEmpty()) 
   {
        byte[] bytes = file.getBytes();
        // and so on
    }
}

JQuery的Ajax：

function saveFileUpload() {
    let data = new FormData()
    data.append("file", document.getElementById(fileName).files[0])

    $.ajax({
        type: 'POST',
        data: data,
        url: pageContext + "/upload",
        processData: false,
        contentType: false,
        success: function(data) {},
        error: function(e) {}
    });
}

I assume that you are using Springboot and your application supports multipart/form-data. After version 3.0 the Servlet API natively support it.

@RequestMapping(value = "/upload", method = RequestMethod.POST)
public void fileUpload(@RequestParam("file") MultipartFile file) throws IOException 
{
    if (!file.isEmpty()) 
   {
        byte[] bytes = file.getBytes();
        // and so on
    }
}

JQuery's Ajax:

function saveFileUpload() {
    let data = new FormData()
    data.append("file", document.getElementById(fileName).files[0])

    $.ajax({
        type: 'POST',
        data: data,
        url: pageContext + "/upload",
        processData: false,
        contentType: false,
        success: function(data) {},
        error: function(e) {}
    });
}

回复收藏 0 原文

~没有更多了~