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Save embedded files from .xls document (Apache POI)

I would like to save all attached files from an Excel (xls/HSSF) without extension.
I've been trying for a long time now, and I really don't know if this is even possible. I also tried Apache Tika, but I don't want to use Tika for this, because I need POI for other tasks, anyway.
I tried the sample code from the Busy Developers Guide, but this does not extract files in the old office format (doc, ppt, xls). And it throws an Error when trying to create new SlideShow(new HSLFSlideShow(dn, fs)) Error: (Remove argument to match HSLFSlideShow(dn))
My actual code is:
public static void saveEmbeddedXLS(InputStream fis_param, String embDIR) throws IOException, InvalidFormatException{
//HSSF - XLS
int i = 0;
System.out.println("Starting Embedded Search in xls...");
POIFSFileSystem fs = new POIFSFileSystem(fis_param);//create FileSystem using fileInputStream
HSSFWorkbook workbook = new HSSFWorkbook(fs);
for (HSSFObjectData obj : workbook.getAllEmbeddedObjects()) {
System.out.println("Objects : "+ obj.getOLE2ClassName());//the OLE2 Class Name of the object
String oleName = obj.getOLE2ClassName();//Document Type
DirectoryNode dn = (DirectoryNode) obj.getDirectory();//get Directory Node
//Trying to create an input Stream with the embedded document, argument of createDocumentInputStream should be: String; Where/How can I get this correct parameter for the function?
InputStream is = dn.createDocumentInputStream(dn);//This line is incorrect! How can I do i correctly?
FileOutputStream fos = new FileOutputStream("embDIR" + i);//Outputfilepath + Number
IOUtils.copy(is, fos);//FileInputStream > FileOutput Stream (save File without extension)
i++;
}
}
So my simple question is:
Is it possible to save ALL attachments from an xls file without any extension (as simple as possible)? And can any one provide me a solution? Many Thanks!

Create a csv or simple text file using only streams

I'm about to use a jsf Primefaces download button to download a csv file.
The file doesn't exists and it can't use the Export utility because I need to build the csv at runtime.
This is a test attempt which works:
private StreamedContent file;
/** Getter,setter...*/
public void FileDownloadBean() {
InputStream stream = this.getClass().getResourceAsStream("test.csv");
file = new DefaultStreamedContent(stream, "application/csv", "test.csv");
}
The fact I'm using Primefaces doesn't really count here, what I want to achieve is to build a file of any kind, preferably CSV, without actually saving a (temp) file in the file-system.
I would like to append my data using a stream, so then I can easily append and manipulate Strings, bytes, and image files.
Any ideas? Maybe a Stringbuffer?
Thanks in advance.

I don't think you can "create a file without creating a file".
Use a String, StringBuffer, StringBuilder, or other variable to have the file's contents in memory.
Edit: Apparently, there are also streams to memory (?): ByteArrayInputStream and ByteArrayOutputStream

As far as I understood your question, the following answer "maybe" solves your problem:
public class InMemoryStreaming {
private StringBuilder sb = new StringBuilder();
public void FileDownloadBean() throws IOException {
InputStream csvStream = this.getClass().getResourceAsStream("test.csv");
try (BufferedReader br = new BufferedReader(new InputStreamReader(
csvStream))) {
// on every method call the StringBuilder is appended
sb.append(br.lines().collect(
Collectors.joining(System.lineSeparator())));
}
}
}
If you want to serialize the StringBuilder into a real File, you can do it with the appropriate writer.

iText mergeFields in PdfCopy creates invalid pdf

I am working on the task of merging some input PDF documents using iText 5.4.5. The input documents may or may not contain AcroForms and I want to merge the forms as well.
I am using the example pdf files found here and this is the code example:
public class TestForms {
#Test
public void testNoForms() throws DocumentException, IOException {
test("pdf/hello.pdf", "pdf/hello_memory.pdf");
}
#Test
public void testForms() throws DocumentException, IOException {
test("pdf/subscribe.pdf", "pdf/filled_form_1.pdf");
}
private void test(String first, String second) throws DocumentException, IOException {
OutputStream out = new FileOutputStream("/tmp/out.pdf");
InputStream stream = getClass().getClassLoader().getResourceAsStream(first);
PdfReader reader = new PdfReader(new RandomAccessFileOrArray(
new RandomAccessSourceFactory().createSource(stream)), null);
InputStream stream2 = getClass().getClassLoader().getResourceAsStream(second);
PdfReader reader2 = new PdfReader(new RandomAccessFileOrArray(
new RandomAccessSourceFactory().createSource(stream2)), null);
Document pdfDocument = new Document(reader.getPageSizeWithRotation(1));
PdfCopy pdfCopy = new PdfCopy(pdfDocument, out);
pdfCopy.setFullCompression();
pdfCopy.setCompressionLevel(PdfStream.BEST_COMPRESSION);
pdfCopy.setMergeFields();
pdfDocument.open();
pdfCopy.addDocument(reader);
pdfCopy.addDocument(reader2);
pdfCopy.close();
reader.close();
reader2.close();
}
}
With input files containing forms I get a NullPointerException with or without compression enabled.
With standard input docs, the output file is created but when I open it with Acrobat it says there was a problem (14) and no content is displayed.
With standard input docs AND compression disabled the output is created and Acrobat displays it.
Questions
I previously did this using PdfCopyFields but it's now deprecated in favor of the boolean flag mergeFields in the PdfCopy, is this correct? There's no javadoc on that flag and I couldn't find documentation about it.
Assuming the answer to the previous question is Yes, is there anything wrong with my code?
Thanks

We are using PdfCopy to merge differents files, some of files may have fields. We use the version 5.5.3.0. The code is simple and it seems to work fine, BUT sometimes the result file is impossible to print!
Our code :
Public Shared Function MergeFiles(ByVal sourceFiles As List(Of Byte())) As Byte()
Dim document As New Document()
Dim output As New MemoryStream()
Dim copy As iTextSharp.text.pdf.PdfCopy = Nothing
Dim readers As New List(Of iTextSharp.text.pdf.PdfReader)
Try
copy = New iTextSharp.text.pdf.PdfCopy(document, output)
copy.SetMergeFields()
document.Open()
For fileCounter As Integer = 0 To sourceFiles.Count - 1
Dim reader As New PdfReader(sourceFiles(fileCounter))
reader.MakeRemoteNamedDestinationsLocal()
readers.Add(reader)
copy.AddDocument(reader)
Next
Catch exception As Exception
Throw exception
Finally
If copy IsNot Nothing Then copy.Close()
document.Close()
For Each reader As PdfReader In readers
reader.Close()
Next
End Try
Return output.GetBuffer()
End Function

Your usage of PdfCopy.setMergeFields() is correct and your merging code is fine.
The issues you described are because of bugs that have crept into 5.4.5. They should be fixed in rev. 6152 and the fixes will be included in the next release.
Thanks for bringing this to our attention.

Its just to say that we have the same probleme : iText mergeFields in PdfCopy creates invalid pdf. So it is still not fixed in the version 5.5.3.0

Creating a ° in a xaml file

So, I'm making a xaml file using java. This is my line of code in java :
String newAnswer = e.getText().substring(0, 1) + "º" + e.getText().substring(2);
Now
"º"
This part should, according to Google, create a degrees symbol in my xaml file, however when I open the output file in xaml I get this: º , if i remove the amp; part it is correct, but I'd like Kaxaml to stop adding that in the first place, if anyone knows how to achieve this, that'd be greatly appreciated.
This is how my xaml gets saved
Utilities.saveXml(d, "Scherm1.xaml");
Utilities:
public static void saveXml(Document document, String fileName) throws IOException {
FileWriter writer;
XMLOutputter outputter;
outputter = new XMLOutputter();
outputter.setFormat(Format.getPrettyFormat());
writer = new FileWriter(fileName);
outputter.output(document, writer);
writer.flush();
writer.close();
}

try using
+ <TextBlock º"/>

Writing in the beginning of a text file Java

I need to write something into a text file's beginning. I have a text file with content and i want write something before this content. Say i have;
Good afternoon sir,how are you today?
I'm fine,how are you?
Thanks for asking,I'm great
After modifying,I want it to be like this:
Page 1-Scene 59
25.05.2011
Good afternoon sir,how are you today?
I'm fine,how are you?
Thanks for asking,I'm great
Just made up the content :) How can i modify a text file like this way?

You can't really modify it that way - file systems don't generally let you insert data in arbitrary locations - but you can:
Create a new file
Write the prefix to it
Copy the data from the old file to the new file
Move the old file to a backup location
Move the new file to the old file's location
Optionally delete the old backup file

Just in case it will be useful for someone here is full source code of method to prepend lines to a file using Apache Commons IO library. The code does not read whole file into memory, so will work on files of any size.
public static void prependPrefix(File input, String prefix) throws IOException {
LineIterator li = FileUtils.lineIterator(input);
File tempFile = File.createTempFile("prependPrefix", ".tmp");
BufferedWriter w = new BufferedWriter(new FileWriter(tempFile));
try {
w.write(prefix);
while (li.hasNext()) {
w.write(li.next());
w.write("\n");
}
} finally {
IOUtils.closeQuietly(w);
LineIterator.closeQuietly(li);
}
FileUtils.deleteQuietly(input);
FileUtils.moveFile(tempFile, input);
}

I think what you want is random access. Check out the related java tutorial. However, I don't believe you can just insert data at an arbitrary point in the file; If I recall correctly, you'd only overwrite the data. If you wanted to insert, you'd have to have your code
copy a block,
overwrite with your new stuff,
copy the next block,
overwrite with the previously copied block,
return to 3 until no more blocks

As #atk suggested, java.nio.channels.SeekableByteChannel is a good interface. But it is available from 1.7 only.
Update : If you have no issue using FileUtils then use
String fileString = FileUtils.readFileToString(file);

This isn't a direct answer to the question, but often files are accessed via InputStreams. If this is your use case, then you can chain input streams via SequenceInputStream to achieve the same result. E.g.
InputStream inputStream = new SequenceInputStream(new ByteArrayInputStream("my line\n".getBytes()), new FileInputStream(new File("myfile.txt")));

I will leave it here just in case anyone need
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
try (FileInputStream fileInputStream1 = new FileInputStream(fileName1);
FileInputStream fileInputStream2 = new FileInputStream(fileName2)) {
while (fileInputStream2.available() > 0) {
byteArrayOutputStream.write(fileInputStream2.read());
}
while (fileInputStream1.available() > 0) {
byteArrayOutputStream.write(fileInputStream1.read());
}
}
try (FileOutputStream fileOutputStream = new FileOutputStream(fileName1)) {
byteArrayOutputStream.writeTo(fileOutputStream);
}