ByteUtils in java

 package com.ack.security;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class ByteUtils {
  private static final int DEFAULT_CHUNK_SIZE = 1024;


  /**
   * save bytes to file
   * @param fileName the file to write the supplied bytes
   * @param theBytes the bytes to write to file
   * @throws java.io.IOException reports problems saving bytes to file
   */
  public static void saveBytesToFile( String fileName, byte[] theBytes )
      throws java.io.IOException {
    saveBytesToStream( new java.io.FileOutputStream( fileName ), theBytes );
  }

  /**
   * save bytes to output stream and close the output stream on success and
   * on failure.
   * @param out the output stream to write the supplied bytes
   * @param theBytes the bytes to write out
   * @throws java.io.IOException reports problems saving bytes to output stream
   */
  public static void saveBytesToStream( java.io.OutputStream out, byte[] theBytes )
      throws java.io.IOException {
    try {
      out.write( theBytes );
    }
    finally {
      out.flush();
      out.close();
    }
  }

  /**
   * Loads bytes from the file
   *
   * @param fileName file to read the bytes from
   * @return bytes read from the file
   * @exception java.io.IOException reports IO failures
   */
  public static byte[] loadBytesFromFile( String fileName ) throws java.io.IOException {
    return loadBytesFromStream( new java.io.FileInputStream( fileName ), DEFAULT_CHUNK_SIZE );
  }

  /**
   * Loads bytes from the given input stream until the end of stream
   * is reached.  It reads in at kDEFAULT_CHUNK_SIZE chunks.
   *
   * @param stream to read the bytes from
   * @return bytes read from the stream
   * @exception java.io.IOException reports IO failures
   */
  public static byte[] loadBytesFromStream( java.io.InputStream in ) throws java.io.IOException {
    return loadBytesFromStream( in, DEFAULT_CHUNK_SIZE );
  }

  /**
   * Loads bytes from the given input stream until the end of stream
   * is reached.  Bytes are read in at the supplied <code>chunkSize</code>
   * rate.
   *
   * @param stream to read the bytes from
   * @return bytes read from the stream
   * @exception java.io.IOException reports IO failures
   */
  public static byte[] loadBytesFromStream( java.io.InputStream in, int chunkSize )
      throws java.io.IOException {
    if( chunkSize < 1 )
      chunkSize = DEFAULT_CHUNK_SIZE;

    int count;
    java.io.ByteArrayOutputStream bo = new java.io.ByteArrayOutputStream();
    byte[] b = new byte[chunkSize];
    try {
      while( ( count = in.read( b, 0, chunkSize ) ) > 0 ) {
        bo.write( b, 0, count );
      }
      byte[] thebytes = bo.toByteArray();
      return thebytes;
    }
    finally {
      bo.close();
    }
  }
}