Reading a file from a local directory into a byte array

Wednesday, December 17, 2008

This can be done with the following code:

public static byte[] getBytesFromFile(File file) throws IOException {
InputStream is = new FileInputStream(file);

// Get the size of the file
long length = file.length();

if (length > Integer.MAX_VALUE) {
// File is too large
}

// Create the byte array to hold the data
byte[] bytes = new byte[(int)length];

// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}

// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}

// Close the input stream and return bytes
is.close();
return bytes;
}

Labels: Technology