Formatting a byte array

Hi,
Unfortunately I do not have a very specific question here; I'm looking for some direction.
I have an application that is receiving a large buffer of bytes, 680x480 if I recall correctly, and I'm basically wondering how to format that buffer to display on the system outputstream.
I've never actually done any work with bytes, and I knew that would one day catch up to me and haunt me.
I looked in the Java tutorial here at Sun for methods of formatting and working with bytes, but I didn't find anything. I might have completely missed it though, so if that's the case, if I could get a link to the appropriate section I'd be grateful.
Anyway, this is what I currently have:
//this returns a large buffer of type byte[]
//this should be 680x480
byte[] image = imAq.acquireImage();
System.out.println(image);Obviously outputting image does not give me anything useful.
These bytes will eventually be transformed into an image, but all I want to do now is print each byte in the buffer to the system outputstream.
I'd be very appreciative if someone can direct me to a tutorial or API doc or something that I can use to learn how to work with bytes and format them and such to perform tasks such as this.
Thanks,
Dan
Message was edited by:
Djaunl

I can't see why this would be very useful ... but
this will print the bytes to the console.
DataInputStream dis = new DataInputStream(
new
FileInputStream("filename"));
byte b = 0;
while ( (b = (byte)dis.read() ) != -1 )
System.out.print(b);
t's really useless though. What do you really want to
do?Thanks for the replies.
The reason I want to print the array to the system outputstream is to make sure the image data is coming in correctly from the server, as it giving us some issues at the moment.
What I really want to do is take this array of bytes and convert it into an image, but first we need to make sure the image is loading correctly from the server.
Thanks for the advice and links guys, I'll check them out and put them to use, as they will certainly help me learn.

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        encoder.encode(image);
    }Note: Through ImageServlet is a Servlet i would categorise it under presentation layer rather to be a part of Controller and added to it all this could be easily relaced by a reporting(BI) server like JasperServer,Pentaho,Actuate................
Hope the stated implementation had given some idea to you....
However,If you want to further look into similar implementations take a look at
http://www.swiftchart.com/exampleapp.htm#e5
which i believe to be a wonderful tutor for such implementations...
However, there are many simple (Open) solutions to the stated problem.. if you are Using MyFaces along with spring... i would recommend usage of JSF Chart Tag which is very simple to use all it requires need is to write a chart Object generating methos inside our backing bean.
For further reference have a look at the below links
http://www.jroller.com/page/cagataycivici?entry=acegi_jsf_components_hit_the
http://jsf-comp.sourceforge.net/components/chartcreator/index.html
NOTE:I've tried it personally using MyFaces it was working gr8 but i had a hardtime on deploying my appln on a Portal Server(Liferay).If you find a workaround i'd be glad to know about it.
& there are many BI Open Source Server Appls that can take care of this work too.(Maintainace wud be a tough ask when we go for this)
For, the design perspective had i've been ur PM i wud have choose BI Server if it was corporate web appln on which we work on.
Hope this might be of some help :)
REGARDS,
RaHuL

Image Byte Array - Hex?

Hi all,
I'm trying to read in an image and get an int / hex array out of it. Basically, I want to get an array that would look like what you see if you open an image in a hex editor. I have no problems getting a byte array using..
ByteArrayOutputStream stream = new ByteArrayOutputStream();
ImageIO.write( bufferedImage, "jpg", stream );
bytes = stream.toByteArray();
But, it's weird, it's not really what I want. The result is not the same as what I see if I drop the same image into a hex editor and look at the bytes. Not sure if I need to convert the bytes to hex or what. Any help would be much appreciated.

hmm.. can you explain a bit?.. let's say I do...
BufferedImage srcImage = ImageIO.read( new File( pathIn ));
ByteArrayOutputStream streamIn = new ByteArrayOutputStream();
ImageIO.write( srcImage , "jpg", streamIn );
byte[] bytes = stream.toByteArray();
ByteArrayInputStream streamOut = new ByteArrayInputStream( bytes );
BufferedImage writeImage = ImageIO.read( streamOut );
ImageIO.write( writeImage, "jpg", new File( pathOut ));Looks a little odd out of context, I know. But, basically, the resulting image is different than the original image. I assume, maybe, there is some sort of compression going on. But i don't really know. Should I be decoding / encoding in specific formats to get the resulting image to be /exactly/ the same as the source?
thanks

Method to create Player directly from the mp3 bytes array

I was checking JMF and didn't find any method to play a mp3 informing its byte array
Wouldn't it be an interesting method ? Ok, URL is much easier, but I am talking about ID3 files that has sequences of mp3 chuncks in the same file... Anyone knows a way to build a Player from mp3' array of bytes ???

sergio_abreu wrote:
Err, Sorry but I desagree.I expected as much
It seems you didn't understand my question well.Quite possibly
I think the form I wrote was confusing:
In +"Anyone knows a way to build a Player from mp3' array of bytes ???+"
I meant: Anyone knows a way to create a Player or MediaPlayer CLASS from DYNAMIC mp3' array of bytes ???That's even less coherent, to be honest
Have you seen the structure of an ID3 music file (album) ? It's a collection of mp3 chuncks in only one file.ID3 is simply metadata about a work. It is not "chunks of MP3"
I have already designed a ID3 class (I called "ID3Info" ) in Java that extracts/shows (dump) all the mp3 from the ID3 file.ID3 isn't a file format. Nor can you extract an MP3 from it
The thing I would need now is to have some methods in Manager Class from which I could choose which bytes of a generic file I want to load as an mp3 song, that's all.This makes zero sense. Like saying "I need a kettle which will turn furniture into weather"
It would be nice if there were 2 new different methods:
1) Player createRealizedPlayer( byte[] songBytes, String fileExtension);
Arguments: the song byte array and the extension, ex. "mp3"And what would this method do? Where does the byte[] come from? What is in the file, that you also need in order to play the song? How is this - assuming it's possible - easier, better, than just playing the file?
2) Player createRealizedPlayer( java.net.URL genericFileURL, int beginPosition, int endPosition, String fileExtension);
Arguments: the URL of a file containing varios mp3 chuncks and the begin / end of the bytes to be loaded as a song and a String to describe the type of file ("mp3" for example)See above
PS: If you find it interesting, I am willing to contribute to enrich even more the Java Media framework. If you think my ideas are not valid, I just ask someone to send me the jmf source code so that I can alter some classes for my tests only.Why do you need JMF source code? I don't think this magical upside-down-ness is going to enhance anything, to be honest

Byte Array from SQL Reporting Service

I am calling the Render method of the Microsoft SQL Reporting
Service's ReportExecution web service. It returns a Byte array in
the lastResult object. I am having the hardest time figuring out a
way to convert that byte array into something I can use in Flex.
The byte array, once converted into a more user friendly format,
will contain the rendered version of a SQL Report in whatever
format I have specified...in this case it is XML. Any input or
suggestions would be appreciated.

This is a little late, I know. but I just spent the day
struggling with this very issue. Hopefully this can help someone
else in the future. Here's my solution...
on MX:Operation -- result="fillXML()"
then
private function fillXML(): void {
var x:XML = new
XML(wsProps.GetDatasetData.lastResult.toString());
...do what you need with your xml...
I use an XMLList node of the result as the source property
for an XMLListCollection bound to a datagrid. Let me know if you
need more help to get it working. It works like a charm now that I
figured that out. I don't know if it's a slimy hack, or not, but it
gets the job done.

From MD5-string to byte array

Hi fellows, I'm writing a simple cracker for MD5. The hash value has to be passed at command line as argument.
e.g.
java Cracker 0cc175b9c0f1b6a831c399e269772661In order to decode the hash value I'm using a brute force approach: therefore I compare a series of strings with the hash value by using the method of the class MessageDigest isEqual(byte[] a, byte[] b). So I encode each string and compare the byte array I get with the byte array of the hash value.
Here it comes the trouble I'm in:
when I try to get a bytes array of the MD5 hash value passed as argument of the program , I do get something, but it's not something that the isEqual method of MessageDigest can use to compare. As a result any attempt during the execution of brute force fails, even though the key is one of the string being checked.
Perhaps am I facing a format problem? Any idea?
Sorry for my english, it's not my first language
Thanks to whoever will help

Almost all questions in these forums about brute force attack on MD5 (or SHA1 or SHA256 etc etc etc) are school, college or university projects and of no practical use. This is almost certainly such a project.
Unless things have changed in the last year, there is no practical brute force attack on MD5 whereby an input can be generated from an arbitrary output even though two inputs with the same output can be fabricated. A dictionary attack is feasible if no salt is used or a known salt is used since one only has to build the dictionary for one salt value. If a different salt is used for each entry being attacked then a dictionary will be need for each salt being used. Of course if one takes the simple precaution of not using anything that is likely to be in a dictionary then the dictionary attack will likely fail.

Formatting a byte array

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