Hi, i need some help because i dont know much about java (either about english) and i have to make a program to compress files with a new algorithm i am developing. The problem is that i dont know how to read the binary code of the files. I dont know if it is using DatainputStream and readBytes or something like that... but i want the bit information not the byte one (i dont know if itīs clear enought). The second problem is i dont know to put the results again in a file. If you have any idea please tell me. thanks.

Is there a reason that you are doing this in Java rather than C or C++?? My experience is that working at the bit/byte level in Java is not terribly easy. Not that I have done it, but experienced Java programmers I know had lots of trouble doing this type of stuff that I could do in C very quickly and easily. Maybe it's easy and these guys just didn't know the right classes to use.

The program must be done in Java.

I don't know how to do it in C++, but Don ain't kidding when he says it's no picnic to do it in Java. To get input from a file you would probably use something like: FileReader fr=new FileReader ("c:\test.txt"); Now that you have a FileReader, you can read one character at a time: int i; i=(int)fr.read(); Now you can get a String of binary characters from this int: String s=Integer.toBinaryString (i); You can now test each character of the String to find out if it is a one or a zero if (s.charAt (i)==1) The outputing to a file is similar to the reading, just use the FileWrite class. I got all this from Java's documentation on their website: http://java.sun.com/j2se/1.4.1/docs/api/ The above method is crap when it comes to efficiency (of course, if you're doing it in Java in the first place you can't possibly be too worried about efficiency:-) So anybody else have a more efficient solution? Good luck, -SN

Hi - I admit Java file I/O can seem like dark magic to someone not familiar with the language and supplied classes. I think you want to use the Stream classes, not the Reader/Writer classes (you are reading binary data I assume, not just text characters). I hope the following will get you started, there is lots of exception/error checking it could do but does not: import java.io.*; public class fileread { public static void main(String[] args) { new fileread().go(args); } private void go(String[] args) { String inF = "infile.txt"; String oF = "outfile.txt"; FileInputStream ifs = null; FileOutputStream ofs = null; BufferedInputStream bis = null; BufferedOutputStream bos = null; byte[] inbuffer = new byte[4096]; byte[] outbuffer = new byte[4096]; try { ifs = new FileInputStream(inF); bis = new BufferedInputStream(ifs, 4096); ofs = new FileOutputStream(oF,false); bos = new BufferedOutputStream(ofs, 4096); int lr = 0; while( (lr = bis.read(inbuffer, 0, 4096)) != -1) { // Compress data to 'outbuffer' System.arraycopy(inbuffer, 0, outbuffer, 0, lr); bos.write(outbuffer, 0, lr); } bis.close(); bos.close(); } catch(Throwable t) { } } } HTH, Guy

thanks guy! iīll try this code. you were right i want to use the Stream classes because as i said i want to make a to compress all kind of files not only text ones.. . Also if you (or somebody else) Know something about coding i will hear any idea. I making a compressor based in the classical LEMPEL-ZIV coding. So if someone knows were can i find some ideas to improve it tell me. Thank in advance. thanks again guy thanks SN.