import java.io.FileInputStream;  import java.io.FileOutputStream;  import java.io.InputStream;  import java.io.OutputStream;  import java.security.Security;  import java.security.spec.AlgorithmParameterSpec;    import javax.crypto.Cipher;  import javax.crypto.CipherInputStream;  import javax.crypto.CipherOutputStream;  import javax.crypto.KeyGenerator;  import javax.crypto.SecretKey;  import javax.crypto.spec.IvParameterSpec;    public class Main {        static Cipher ce;      static Cipher cd;        public static void main(String args[]) throws Exception {            Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());            SecretKey skey = KeyGenerator.getInstance("DES").generateKey();            byte[] initializationVector = new byte[]{0x10, 0x10, 0x01, 0x04, 0x01, 0x01, 0x01, 0x02};            AlgorithmParameterSpec algParameters = new IvParameterSpec(initializationVector);          ce = Cipher.getInstance("DES/CBC/PKCS5Padding");          cd = Cipher.getInstance("DES/CBC/PKCS5Padding");            ce.init(Cipher.ENCRYPT_MODE, skey, algParameters);          cd.init(Cipher.DECRYPT_MODE, skey, algParameters);            FileInputStream is = new FileInputStream("C:/Users/nikos7/Desktop/output.txt");          FileOutputStream os = new FileOutputStream("C:/Users/nikos7/Desktop/output2.txt");          int dataSize = is.available();            byte[] inbytes = new byte[dataSize];          is.read(inbytes);            String str2 = new String(inbytes);          System.out.println("Input file content\n" + str2 + "\n");            write_encode(inbytes, os);            os.flush();          is.close();          os.close();            System.out.println("Ecrypted Content to output2.txt\n");            is = new FileInputStream("C:/Users/nikos7/Desktop/output2.txt");            byte[] decBytes = new byte[dataSize];            read_decode(decBytes, is);            is.close();            String str = new String(decBytes);            System.out.println("Decrypted file contents:\n" + str);        }        public static void write_encode(byte[] bytes, OutputStream output) throws Exception {          CipherOutputStream cOutputStream = new CipherOutputStream(output, ce);          cOutputStream.write(bytes, 0, bytes.length);          cOutputStream.close();      }        public static void read_decode(byte[] bytes, InputStream input) throws Exception {          CipherInputStream cInputStream = new CipherInputStream(input, cd);          int position = 0, i;            while ((i = cInputStream.read()) != -1) {              bytes[position] = (byte) i;              position++;          }      }  }