I need to append binary data to file but before this data is an xml header. Whole file wont be proper xml file but it must proper xml header like following:
<EncryptedFileHeader>
<Algorithm>name</Algorithm>
<KeySize>256</KeySize>
<SubblockLength>64</SubblockLength>
<CipherMode>ECB</CipherMode>
<sessionKey>sessionKey</sessionKey>
</EncryptedFileHeader>
*binary data*
The xml header I do with JAXB marshalling easily, and even easier would be to add this binary data in base64 and store in note inside xml. But this is a clue. I have to store it as binary to save this overhead 33% space used by base64.
So the question is how to add this data and of course later read this back (serialize/deserialize) ?
Another question is how to remove from the first line of document?
I tried to use:
marshaller.setProperty("com.sun.xml.bind.xmlDeclaration", Boolean.FALSE);
but it throws an exception:
javax.xml.bind.PropertyException: name: com.sun.xml.bind.xmlDeclaration value: false
at javax.xml.bind.helpers.AbstractMarshallerImpl.setProperty(AbstractMarshallerImpl.java:358)
at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.setProperty(MarshallerImpl.java:527)
Thanks
Actualy I solved this by serializing xml header with JAXB, then appending binary data (bytearray) to existing file.
Reading from file with buffered reader as follows:
BufferedReader reader = new BufferedReader(new FileReader("filepath"));
String line, results = "";
while ((line = reader.readLine()) != null) {
results += line;
}
reader.close();
String[] splited = results.split("</EncryptedFileHeader>");
splited[0] += "</EncryptedFileHeader>";
String s0 = splited[0];
String s1 = new String(splited[1]);
ByteArrayInputStream bais = new ByteArrayInputStream(s0.getBytes());
Now i got a problem with second splited string s1, which consist data from "byteArrayOutputStream.toByteArray();". Now I have to transfer data from this string to byte array. From:
'��A����g�X���
to something like:
[39, -63, -116, 65, -123, -114, 27, -115, -2, 103, -64, 88, -99, -96, -26, -12]
I tried (on the same machine):
byte[] bytes = s1.getBytes();
but bytes array is different and returns 34 bytes instead 16. I read a lot about encodings but still have no idea.
EDIT:
The problem with different number of bytes was due to the different representation of new line by character and byte streams.
Related
This barcode:
Will not decode. What is wrong with that image that it will not decode.
string barcodePng = "tmp.png";
reader = new BarcodeReader();
reader.Options.PossibleFormats = new List<BarcodeFormat>();
reader.Options.PossibleFormats.Add(BarcodeFormat.CODE_39);
reader.Options.TryHarder = true;
using (var barcodeBitmap = new Bitmap(barcodePng))
{
var result = reader.Decode(barcodeBitmap);
if (result != null)
{
Console.WriteLine("barcode did not decode");
}
}
This one is different from other thousands of other images that did decode in that I had to repair the original .tif file that it was cut from because it was damaged. I repaired it by converting it to .pdf and back to .tif.
What is wrong with that image that it will not decode.
It will not decode because some bars have merged and/or changed their widths due to low resolution and blurring.
Assuming the symbology is Code 39, the valid barcode looks like this:
The Apache Commons compress library seems focused around writing a TarArchiveEntry to TarArchiveOutputStream. But it looks like the only way to create a TarArchiveEntry is with a File object.
I don't have files to write to the Tar, I have byte[]s in memory or preferably streams. And I don't want to write a bunch of temp files to disk just so that I can build a tar.
Is there any way I can do something like:
TarEntry entry = new TarEntry(int size, String filename);
entry.write(byte[] fileContents);
TarArchiveOutputStream tarOut = new TarArchiveOutputStream();
tarOut.write(entry);
tarOut.flush();
tarOut.close();
Or, even better....
InputStream nioTarContentsInputStream = .....
TarEntry entry = new TarEntry(int size, String filename);
entry.write(nioTarContentsInputStream);
TarArchiveOutputStream tarOut = new TarArchiveOutputStream();
tarOut.write(entry);
tarOut.flush();
tarOut.close();
Use the following code:
byte[] test1Content = new byte[] { /* Some data */ };
TarArchiveEntry entry1 = new TarArchiveEntry("test1.txt");
entry1.setSize(test1Content.length);
TarArchiveOutputStream out = new TarArchiveOutputStream(new FileOutputStream("out.tar"));
out.putArchiveEntry(entry1);
out.write(test1Content);
out.closeArchiveEntry();
out.close();
This builds the desired tar file with a single file in it, with the contents from the byte[].
I am using LumenWorks awesome CSV reader to process CSV files. Some files have over 1 million records.
What I want is to process the file in sections. E.g. I want to process 100,000 records first, validate the data and then send this records over an Internet connection. Once sent, I then reopen the file and continue from record 100,001. On and on till I finish processing the file. In my application I have already created the logic of keeping track of which record I am currently processing.
Does the LumenWorks parser support processing from a predetermined line in the CSV or it always has to start from the top? I see it has a buffer variable. Is there a way to use this buffer variable to achieve my goal?
my_csv = New CsvReader(New StreamReader(file_path), False, ",", buffer_variable)
It seems the LumenWorks CSV Reader needs to start at the top - I needed to ignore the first n lines in a file, and attempted to pass a StreamReader that was at the correct position/row, but got a Key already exists Dictionary error when I attempted to get the FieldCount (there were no duplicates).
However, I have found some success by first reading pre-trimmed file into StringBuilder and then into a StringReader to allow the CSV Reader to read it. Your mileage may vary with huge files, but it does help to trim a file:
using (StreamReader sr = new StreamReader(filePath))
{
string line = sr.ReadLine();
StringBuilder sbCsv = new StringBuilder();
int lineNumber = 0;
do
{
lineNumber++;
// Ignore the start rows of the CSV file until we reach the header
if (lineNumber >= Constants.HeaderStartingRow)
{
// Place into StringBuilder
sbCsv.AppendLine(line);
}
}
while ((line = sr.ReadLine()) != null);
// Use a StringReader to read the trimmed CSV file into a CSV Reader
using (StringReader str = new StringReader(sbCsv.ToString()))
{
using (CsvReader csv = new CsvReader(str, true))
{
int fieldCount = csv.FieldCount;
string[] headers = csv.GetFieldHeaders();
while (csv.ReadNextRecord())
{
for (int i = 0; i < fieldCount; i++)
{
// Do Work
}
}
}
}
}
You might be able to adapt this solution to reading chunks of a file - e.g. as you read through the StreamReader, assign different "chunks" to a Collection of StringBuilder objects and also pre-pend the header row if you want it.
Try to use CachedCSVReader instead of CSVReader and MoveTo(long recordnumber), MoveToStart etc. methods.
I'm trying to read in a text file to a String variable. The text file has multiple lines.
Having printed the String to test the "read-in" code, there is an additional space between every character. As I am using the String to generate character bigrams, the spaces are making the sample text useless.
The code is
try {
FileInputStream fstream = new FileInputStream(textfile);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
//Read corpus file line-by-line, concatenating each line to the String "corpus"
while ((strLine = br.readLine()) != null) {
corpus = (corpus.concat(strLine));
}
in.close(); //Close the input stream
}
catch (Exception e) { //Catch exception if any
System.err.println("Error test check: " + e.getMessage());
}
I'd be grateful for any advice.
Thanks.
Your text file is likely to be UTF-16 (Unicode) encoded. UTF-16 takes two or four bytes to represent each character. For most western text files, the "in-between" bytes are non-printable and will look like spaces.
You can use the second argument of InputStreamReader to specify the encoding.
Alternatively, modify the text file (iconv on Unix, Save As.. dialog in Notepad on Windows):
I have a .resx file to update some data. I can read the data from the file via a ResXResourceSet object, but when I want to save the data back, the saved data format is
unrecognizable. How do I edit .resx files? Thanks.
ResXResourceSet st = new ResXResourceSet(#"thepath");
entries=new List<DictionaryEntry>();
DictionaryEntry curEntry ;
foreach (DictionaryEntry ent in st)
{
if (ent.Key.ToString() == "Page.Title")
{
curEntry = ent;
curEntry.Value = "change this one"
entries.Add(curEntry);
}
else
{
entries.Add(ent);
}
}
st.Close();
System.Resources.ResourceWriter wr = new ResourceWriter(#"thepath");
foreach (DictionaryEntry entry in entries)
{
wr.AddResource(entry.Key.ToString(), entry.Value.ToString());
}
wr.Close();
Hi again i searched up and found that..
ResourceWriter writes data as binary type
ResourceReader reads data as binary type
ResXResourceWriter writes data as xml format
ResXResourceReader reads data as xml format
so example on top using ResXResourceWriter,ResXResourceReader instead of ResourceReader ,ResourceWriter will manipulate resources as xml type