Pack/unpack matching test

RnRBinTest.java

import com.arxcin.RnRBinAPI;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.List;
import java.util.ArrayList;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class RnRBinTest{
	
	//https://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to-a-hex-string-in-java
	private final static char[] hexArray = "0123456789ABCDEF".toCharArray();
	
	public static void main(String[] args) throws Exception{//FORGIVE ME
		if(args.length != 2){
			System.err.println("Need 2 args!\n[baseDir] [targetFile]");
			System.exit(1);
		}
		File dir = new File(args[0]);
		if(!dir.exists()){
			System.err.println("Error: path " + dir + " does not exist!");
			System.exit(2);
		}else if(!dir.isDirectory()){
			System.err.println("Error: path " + dir + " is not a directory!");
			System.exit(3);
		}
		File[] files = dir.listFiles();
		File outFile = new File(args[1]);
		outFile.getAbsoluteFile().getParentFile().mkdirs();
		try{
			outFile.createNewFile();
		}catch(IOException e){
			System.err.println("Error creating new file at path \"" + outFile + "\" Details:\n" + e);
			System.exit(4);
		}
		PrintWriter pw = null;
		try{
			pw = new PrintWriter(outFile);
		}catch(FileNotFoundException e){
			System.err.println("Hail hydra.");
			System.exit(1131);
		}
		for(int j = 0; j < files.length; j++){
			if(files[j].isFile()){
				FileInputStream stream = null;
				byte[] data = new byte[(int)files[j].length()];
				try{
					stream = new FileInputStream(files[j]);
				}catch(FileNotFoundException e){
					System.err.println("Error: File \"" + files[j] + "\" does not exist... Impossible... Details:\n" + e);
					System.exit(5);
				}
				try{
					stream.read(data);
				}catch(IOException e){
					System.err.println("Error: IOException while reading file \"" + files[j] + "\" Details:\n" + e);
					System.exit(6);
				}
				try{
					stream.close();
				}catch(IOException e){
					System.err.println("Error: IOException while trying to close FileInputStream! Details:\n" + e);
					System.exit(7);
				}
				List<byte[]> unpacked = RnRBinAPI.unpack(data);
				byte[] packed = RnRBinAPI.pack(unpacked);
				if(!Arrays.equals(data, packed)){
					int countWrong = 0;
					for(int i = 0; i < packed.length; i++){
						if(data[i] != packed[i])
							countWrong++;
					}
					String dang = "[!!] FILE>>" + files[j].getName() + " wrong: " + countWrong;
					System.out.println(dang);
					pw.println(dang);
					for(int i = 0; i < packed.length; i++){
						if(data[i] != packed[i]){
							byte[] d1 = new byte[1];
							d1[0] = data[i];
							byte[] d2 = new byte[1];
							d2[0] = packed[i];
							String d3 = "DiffPos (base 10): " + i + ", vals: " + bytesToHex(d1) + ":" + bytesToHex(d2);
							System.out.println(d3);
							pw.println(d3);
						}
					}
				}else{
					String chill = "[OK] FILE>>" + files[j].getName();
					System.out.println(chill);
					pw.println(chill);
				}
			}
		}
		pw.flush();
		pw.close();
	}

	//https://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to-a-hex-string-in-java
	public static String bytesToHex(byte[] bytes) {
		char[] hexChars = new char[bytes.length * 2];
		for ( int j = 0; j < bytes.length; j++ ) {
			int v = bytes[j] & 0xFF;
			hexChars[j * 2] = hexArray[v >>> 4];
			hexChars[j * 2 + 1] = hexArray[v & 0x0F];
		}
		return new String(hexChars);
	}

}