Read file to byte array and save byte array to file : Byte Array « File Input Output « Java

Read file to byte array and save byte array to file


public class Util{
     * Read bytes from a File into a byte[].
     * @param file The File to read.
     * @return A byte[] containing the contents of the File.
     * @throws IOException Thrown if the File is too long to read or couldn't be
     * read fully.
    public static byte[] readBytesFromFile(File file) throws IOException {
      InputStream is = new FileInputStream(file);
      // Get the size of the file
      long length = file.length();
      // You cannot create an array using a long type.
      // It needs to be an int type.
      // Before converting to an int type, check
      // to ensure that file is not larger than Integer.MAX_VALUE.
      if (length > Integer.MAX_VALUE) {
        throw new IOException("Could not completely read file " + file.getName() + " as it is too long (" + length + " bytes, max supported " + Integer.MAX_VALUE + ")");
      // 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 && (, 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
      return bytes;
     * Writes the specified byte[] to the specified File path.
     * @param theFile File Object representing the path to write to.
     * @param bytes The byte[] of data to write to the File.
     * @throws IOException Thrown if there is problem creating or writing the 
     * File.
    public static void writeBytesToFile(File theFile, byte[] bytes) throws IOException {
      BufferedOutputStream bos = null;
    try {
      FileOutputStream fos = new FileOutputStream(theFile);
      bos = new BufferedOutputStream(fos); 
    }finally {
      if(bos != null) {
        try  {
          //flush and close the BufferedOutputStream
        } catch(Exception e){}


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