Exor Class

package Exor;

import java.io.BufferedReader;
import java.io.CharArrayReader;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.InputStreamReader;

public class Exor {
    String key;

    public Exor(String key) {
        this.key = key;
    }

    public void encrypt() {
        try {
            char[] buffer = new char[1];
             BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
            int i = 0;
            while (in.read(buffer) != -1) {
                buffer[0] = (char) (buffer[0] ^ key.charAt(i));
                i = (i+1) % key.length();
                System.out.print(buffer[0]);
            }
        } catch (IOException e) {
            System.err.println("Exception found in Encrypt: ");
            System.err.println(e);
        }
    }

    public void decrypt()
    {
        try {
            CharArrayWriter file = new CharArrayWriter();
            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));


            char[] c = new char[1];
            while (in.read(c) != -1) {
                file.append(c[0]);
            }

            char[] full_file = new char[file.size()];
            full_file = file.toCharArray();

            for (int key_value = 0; key_value < 100000000; key_value++) {
                String temp_key = String.format("%08d", key_value);

                // KEY IS WORKING, TIME TO HACK IT ALL UP!

                CharArrayWriter poss_out = new CharArrayWriter();
                CharArrayReader poss_in = new CharArrayReader(full_file);

                int i = 0;
                while(poss_in.read(c) != -1) {
                    c[0] = (char) (c[0] ^ temp_key.charAt(i));
                    i = (i+1) % temp_key.length();
                    poss_out.append(c[0]);
                }

                String f_me = poss_out.toString();

                // WE'VE GOT THE POSSIBLE OUTPUT, TIME TO CHECK IF IT'S RIG"HT!
                // hogy, nem, az, ha

                CharSequence val1 = " hogy", val2 = " nem", val3 = " az", val4 = " ha";
                if (f_me.contains(val1) && f_me.contains(val2) && f_me.contains(val3) && f_me.contains(val4)) {
                    System.out.println(temp_key + " ... " + f_me);
                }
                else
                {
                    System.out.println("HIBAS: " + temp_key + " ... " + f_me);
                }
            }
        } catch (IOException e) {
            System.err.println("Exception found in Encrypt: ");
            System.err.println(e);
        }
    }
}