Append data to existing file using SMBJ client

Question

I need to append data to an existing file using the SMBJ client. The below code appends the data, but the final file is corrupted, not able to read/open the file.

 Set<AccessMask> accessMask = new HashSet<>();
 accessMask.add(AccessMask.GENERIC_READ);
 accessMask.add(AccessMask.GENERIC_WRITE);

 Set<FileAttributes> fileAttributes = new HashSet<>();
 fileAttributes.add(FileAttributes.FILE_ATTRIBUTE_NORMAL);

 Set<SMB2CreateOptions> createOptions = new HashSet<>();
 createOptions.add(SMB2CreateOptions.FILE_RANDOM_ACCESS);

 File file = share.openFile("PATH", accessMask, fileAttributes, SMB2ShareAccess.ALL, 
                         SMB2CreateDisposition.FILE_OPEN_IF, createOptions);

 // Approach - 1
 long fileOffset = 0;
 byte[] buffer = new byte[1024*4];
 int length = inputStream.read(buffer);
 while(length != -1){
   fileOffset = share.getFileInformation("PATH").getStandardInformation().getEndOfFile();
   file.write(buffer, fileOffset, 0, lenght);
 }

//Approach - 2
 OutputStream oStream = f.getOutputStream();
     oStream.write(fileContents.getBytes());
     oStream.flush();
     oStream.close();

But from both approaches, not able to append the data properly.

Jokkeri · Answer 1 · 2021-03-26T12:59:05.053

This is how I am doing it:

private static void uploadAppend(File source, DiskShare diskShare,
        String destPath) throws IOException {
    if (source != null && source.exists() && source.canRead()
            && source.isFile()) {

        try (InputStream is = new java.io.FileInputStream(source)) {
            if (destPath != null && is != null) {
                Set<AccessMask> accessMask = new HashSet<>(EnumSet.of(
                        AccessMask.FILE_READ_DATA,
                        AccessMask.FILE_WRITE_DATA, AccessMask.DELETE));
                Set<SMB2ShareAccess> shareAccesses = new HashSet<>(
                        EnumSet.of(SMB2ShareAccess.FILE_SHARE_READ,
                                SMB2ShareAccess.FILE_SHARE_WRITE,
                                SMB2ShareAccess.FILE_SHARE_DELETE));
                Set<FileAttributes> createOptions = new HashSet<>(
                        EnumSet.of(FileAttributes.FILE_ATTRIBUTE_NORMAL));

                try (com.hierynomus.smbj.share.File file = diskShare
                        .openFile(destPath, accessMask, createOptions,
                                shareAccesses,
                                SMB2CreateDisposition.FILE_OPEN_IF,
                                EnumSet.noneOf(SMB2CreateOptions.class))) {

                    int bufferSize = 2048;
                    if (source.length() > 20971520l) {
                        bufferSize = 131072;
                    }
                    byte[] buffer = new byte[bufferSize];
                    long fileOffset = 0;
                    int length = 0;
                    while ((length = is.read(buffer)) > 0) {
                        fileOffset = diskShare.getFileInformation(destPath)
                                .getStandardInformation().getEndOfFile();
                        file.write(buffer, fileOffset, 0, length);
                    }
                    file.flush();
                    file.close();
                } finally {
                    is.close();
                }
            }
        }
    }
}

score 0 · Answer 2 · answered Jul 27 '21 at 13:43

Here is a solution with the jcifs.smb.SmbFileOutputStream and the jcifs.smb.SmbFileInputStream classes:

private void AppendToFile() throws Exception {
        CIFSContext base = SingletonContext.getInstance();
        CIFSContext context = base.withCredentials(new NtlmPasswordAuthentication(base, "domainName",
                "userName", "password"));
        try (SmbFile f = new SmbFile("smb://serverName/folder/test.txt", context)) {
            SmbFileInputStream in = new SmbFileInputStream(f);
            byte[] buffer = new byte[1024]; //your file size
            int bytesRead = in.read(buffer);
            while (bytesRead > 0) {
                bytesRead = in.read(buffer);
            }
            in.close();

//...
//do your operations with the data in buffer
//...


            SmbFileOutputStream out = f.openOutputStream(true); //true is for append mode
            out.write(buffer);
            out.close();
        }
    }

Append data to existing file using SMBJ client

2 Answers2

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