addPrintCharTo.java

private static InputStream addPrintCharTo(byte[]  bArr)
			throws IOException {
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		out.write(INIT);
		//	out.write(CONDENSED);
		//	out.write(PICA);
		out.write(new Byte((byte) 0x21));
		//  out.write(new Byte((byte) 1));
		for (int i = 0; i<bArr.length; i++) {
			out.write(new byte[]{bArr[i]}, 0, 1) ;
		}
		byte[] outArr = out.toByteArray();

		InputStream finalFile = new ByteArrayInputStream(outArr);
		return finalFile;
	}

concatenate.java

private byte[] concatenate(List<File> files) throws FileNotFoundException, IOException {
  	PrintWriter pw = new PrintWriter(new FileOutputStream(Utils.TMP_DIR + "concat.txt"));

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        for (File file : files) {

                System.out.println("Processing " + file.getPath() + "... ");
                BufferedReader br = new BufferedReader(new FileReader(file.getPath()));
            	String line = br.readLine();
                while (line != null) {
                	out.write(line.getBytes());
                	line = br.readLine();
                }
                
                br.close();
        }
        byte[] bArr = out.toByteArray();
        	
        pw.close();
        return bArr ;
	}