Question

我可以从网站下载文件。当我通过java main方法运行它时，文件被下载并且响应是

Content-Type =application/vnd.openxmlformats-officedocument.wordprocessingml.document
Content-Disposition = attachment; 
filename = test.docx
Content-Length = -1
fileName = test.doc
File downloaded

但是当我将它集成到我的spring mvc应用程序中时，它并没有...我得到了响应，

Content-Type =text/html; charset=utf-8 
content-disposition=null
content-length=-1

该文件未下载... 请帮我解决这个问题。提前致谢

    //code
    URL url = new URL(fileURL);
    HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
    httpConn.setRequestMethod("GET");
    httpConn.setRequestProperty("Cookie", "cookie-name");


    //add request header
    httpConn.setRequestProperty("User-Agent", "test");
    int responseCode = httpConn.getResponseCode();
    if (responseCode == HttpURLConnection.HTTP_OK)
    {
        String fileName = "";
        String disposition = httpConn.getHeaderField("Content-Disposition");
        String contentType = httpConn.getContentType();
        int contentLength = httpConn.getContentLength();

        if (disposition != null) 
        {
            // extracts file name from header field
            int index = disposition.indexOf("filename=");
            if (index > 0) {
                fileName = disposition.substring(index + 10,
                        disposition.length() - 1);
        }
        } 
        else 
        {
            // extracts file name from URL
            fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
                    fileURL.length());
        }

        System.out.println("Content-Type = " + contentType);
        System.out.println("Content-Disposition = " + disposition);
        System.out.println("Content-Length = " + contentLength);
        System.out.println("fileName = " + fileName);

        // opens input stream from the HTTP connection
        InputStream inputStream = httpConn.getInputStream();
        String saveFilePath = "E:/" + fileName;

        // opens an output stream to save into file
        FileOutputStream outputStream = new FileOutputStream(saveFilePath);

        int bytesRead = -1;
        byte[] buffer = new byte[BUFFER_SIZE];
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            outputStream.write(buffer, 0, bytesRead);
        }

        outputStream.close();
        inputStream.close();

        System.out.println("File downloaded");
    } 
    else 
    {
        System.out.println("No file to download"):
   }

    httpConn.disconnect();

Answer 1

我明白了。似乎我在调用下载文件的URL中存在问题。 url本身返回了打印响应，而不是下载响应，这就是它无法正常工作的原因。

错误来自我的结局......

感谢所有试图帮助我的人。

通过httpurlconnection方法从互联网下载文件

1 个答案: