How can i convert File to Binary? I just need it for my project. I need to encrypt a file by its binaries.
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3Files are already binary data. Please give more information.Jon Skeet– Jon Skeet2011-08-19 08:52:18 +00:00Commented Aug 19, 2011 at 8:52
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What do you mean by convert a File to binary exactly?James P.– James P.2011-08-19 08:54:14 +00:00Commented Aug 19, 2011 at 8:54
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1if you mean file to byte array: exampledepot.com/egs/java.io/file2bytearray.htmljacop41– jacop412011-08-19 08:55:37 +00:00Commented Aug 19, 2011 at 8:55
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I need to make a program the can encrypt any types of file. Based on our proposal we are going to encrypt file by its binary.Ran Gualberto– Ran Gualberto2011-08-19 08:57:28 +00:00Commented Aug 19, 2011 at 8:57
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1Then see my post. It's what you want. Also discard any of the String stuff... It's now irrelevant.user400055– user4000552011-08-19 09:00:17 +00:00Commented Aug 19, 2011 at 9:00
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4 Answers
If you're referring to accessing the ACTUAL BINARY form then read in the file and convert every byte to a binary representation...
EDIT:
Here's some code to convert a byte into a string with the bits:
String getBits(byte b)
{
String result = "";
for(int i = 0; i < 8; i++)
result += (b & (1 << i)) == 0 ? "0" : "1";
return result;
}
If you're referring to accessing the bytes in the file then simply use the following code (you can use this for the first case as well):
File file = new File("filename.bin");
byte[] fileData = new byte[file.length()];
FileInputStream in = new FileInputStream(file);
in.read(fileData):
in.close();
// now fileData contains the bytes of the file
To use these two pieces of code you can now loop over every byte and create a String object (8X larger than the original file size!!) with the bits:
String content = "";
for(byte b : fileData)
content += getBits(b);
// content now contains your bits.
1 Comment
Ran Gualberto
Do you think I can reverse it. binary representation to file.
try {
StringBuilder sb = new StringBuilder();
File file = new File("C:/log.txt");
DataInputStream input = new DataInputStream( new FileInputStream( file ) );
try {
while( true ) {
sb.append( Integer.toBinaryString( input.readByte() ) );
}
} catch( EOFException eof ) {
} catch( IOException e ) {
e.printStackTrace();
}
System.out.println(sb.toString());
} catch( FileNotFoundException e2 ) {
e2.printStackTrace();
}
Simple explanatory code to encode / decode :
To Encode:
// Encode Character | char
Integer.toBinaryString(myByte);
// Encode Byte | byte
Integer.toBinaryString(myCharacter);
To decode :
// Use BigInteger insted of Integer beacause it can decode large binary code(2)
new BigInteger(data, 2).toByteArray()
Encode file :
private static void encodeToBinary(File inputPath, File outputPath) throws IOException {
// Read all the bytes from the input file
InputStream inputData = new FileInputStream(inputPath);
ByteArrayOutputStream fileData = new ByteArrayOutputStream();
inputData.transferTo(fileData);
// StringJoiner to store binary code(2) encoded
StringJoiner binaryData = new StringJoiner(" ");
// Convert every byte into binaryString
for(Byte data : fileData.toByteArray()) {
binaryData.add(Integer.toBinaryString(data));
}
// (File)OutputStream for writing binary code(2)
OutputStream outputData = new FileOutputStream(outputPath);
outputData.write(binaryData.toString().getBytes());
// [IMPORTANT] Close all the streams
fileData.close();
outputData.close();
inputData.close();
}
Decode file :
private static void decodeToFile(File inputPath, File outputPath) throws IOException {
// -->>Just reverse the process
// Read all the bytes from the input (binary code(2)) file to string
InputStream inputData = new FileInputStream(inputPath);
ByteArrayOutputStream fileData = new ByteArrayOutputStream();
inputData.transferTo(fileData);
// ByteArrayOutputStream to store bytes decoded
ByteArrayOutputStream originalBytes = new ByteArrayOutputStream();
// Convert every binary code(2) to original byte(s)
for(String data : new String(fileData.toByteArray()).split(" ")) {
originalBytes.write(new BigInteger(data, 2).toByteArray());
}
// (File)OutputStream for writing decoded bytes
OutputStream outputData = new FileOutputStream(outputPath);
outputData.write(originalBytes.toByteArray());
// [IMPORTANT] Close all the streams
inputData.close();
fileData.close();
originalBytes.close();
outputData.close();
}
1 Comment
g00se
You can't use
Integer.toBinaryString as its output is of variable length (broken really), so you wouldn't know how to decode itWith FileInputStream you can obtain the bytes from a File
From JavaDoc:
A FileInputStream obtains input bytes from a file in a file system. What files are available depends on the host environment.
FileInputStream is meant for reading streams of raw bytes such as image data. For reading streams of characters, consider using FileReader.
