Question

我正在创建一个程序，它是来自服务器的下载文件

public void downloadFile(String fileURL, String saveDir, String user, String pass, String FileName)
            throws IOException {
        String authString = user + ":" + pass;

        byte[] authEncBytes = Base64.encodeBase64(authString.getBytes());
        String authStringEnc = new String(authEncBytes);

        URL url = new URL(fileURL);
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
        httpConn.setRequestProperty("Authorization", "Basic " + authStringEnc);
        int responseCode = httpConn.getResponseCode();

        // always check HTTP response code first
        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 = saveDir + File.separator + 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. Server replied HTTP code: " + responseCode);
        }
        httpConn.disconnect();
    }

所以当我使用参数下载文件时我遇到了错误输出是

Content-Type = application/http
Content-Disposition = null
Content-Length = 3217551
fileName = 13.25.00-13.26.00[R][0@0][0].dav

Exception in thread "main" java.io.FileNotFoundException: C:\Cam\13.25.00-13.26.00[R][0@0][0].dav
 (The filename, directory name, or volume label syntax is incorrect)
    at java.io.FileOutputStream.open(Native Method)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:221)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:110)
    at dynakode.utility.Downloader.downloadFile(Downloader.java:65)
    at dynakode.camera.DynakodeCamera.cennection(DynakodeCamera.java:50)
    at dynakode.camera.DynakodeCamera.main(DynakodeCamera.java:16)
Java Result: 1

你可以看到错误是文件名，目录名或卷标语法不正确所以如何解决这个问题

我正在更改此行

  String saveFilePath = saveDir + "\\" + "test.dav";

我手动给名字而不是文件下载到驱动程序

输出

Content-Type = application/http
Content-Disposition = null
Content-Length = 3217551
fileName = 13.25.00-13.26.00[R][0@0][0].dav

File downloaded

这是我想要的

问题已修复

@TAsk你写的是Space有问题但是在C：/ cam ..这是来自服务器的文件名有空格" 13.25.00-13.26.00[R][0@0][0].dav"这就是创建问题所以我修剪所有路径

 saveFilePath = saveFilePath.trim();

使用此问题修复了

Answer 1

你的字符串在路径中有\13，它将其视为字符表示。

C:\Cam\13.25.00-13.26.00[R][0@0][0].dav
      ^

您应该将其更改为/或\\

所以改变你的saveFilePath

String saveFilePath = saveDir + "\\" + fileName;
String saveFilePath = saveDir + "/" + fileName;

但是

这不应该是因为File.separator()（由user2864740指出），所以根据我的另一个原因导致这个问题，我认为这是C:之前的额外空间或者在路径的某个地方。

" C:\Cam"+File.separator+"13.25.00-13.26.00[R][0@0][0].dav"
 ^//<-------Extra Space you can use string.trim() to remove extra spaces

修改

我觉得目录（Cam）的最后一件事不存在，可能是造成这种情况的最后一个选项。

Answer 2

因为您指定的路径与预期的路径不同，所以它会抛出java.io.FileNotFoundException

确保您已在cam驱动器

下创建了c目录

线程“main”中的异常java.io.FileNotFoundException Java

2 个答案:

但是