DES encryption and decryption

package com.dc;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.Security;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;

/* ******************** Class description ********************
 * class       :  DcDES
 * @author     :  ncc
 * create time : 2017-12-19 10:19:50 am
 * @version    :  1.0  
 * description : The DES algorithm is a symmetric encryption system in the encryption system, and it has become the US data encryption standard. It was developed by IBM in 1972.
 * Symmetric cryptosystem encryption algorithm. The plaintext is grouped by 64 bits, the key is 64 bits long, and the key is actually 56 bits involved in the DES operation
 * (The 8th, 16th, 24th, 32nd, 40th, 48th, 56th, and 64th bits are the check digit, so that each key has an odd number of 1s) the grouped plaintext group
 * Encryption method that forms a ciphertext group by bitwise substitution or exchange with a 56-bit key
 * @see        :                        
 * ************************************************/   
public class DcDES {

	// KeyGenerator provides the function of a symmetric key generator and supports various algorithms
	private KeyGenerator keygen;
	// SecretKey is responsible for storing the symmetric key
	private SecretKey deskey;
	// Cipher is responsible for completing the encryption or decryption work
	private Cipher c;
	// This byte array is responsible for storing the encrypted result
	private byte[] cipherByte;

	/**
	 * @throws NoSuchAlgorithmException
	 * @throws NoSuchPaddingException
	 */
	public DcDES() throws NoSuchAlgorithmException, NoSuchPaddingException {
		Security.addProvider(new com.sun.crypto.provider.SunJCE());
		// Instantiate a key generator that supports the DES algorithm (the algorithm name must be named as specified, otherwise an exception will be thrown)
		keygen = KeyGenerator.getInstance("DES");
		// generate key
		deskey = keygen.generateKey();
		//Generate a Cipher object and specify the DES algorithm it supports  
		c = Cipher.getInstance("DES");

	}

	/* ********************************************
	 * method name   : Encrytor
	 * description : encrypt the string
	 * @return       : byte[]
	 * @param : @param str
	 * @param        : @return
	 * @param        : @throws InvalidKeyException
	 * @param        : @throws IllegalBlockSizeException
	 * @param        : @throws BadPaddingException
	 * modified      : ncc ,  2017-12-19
	 * @see          :
	 * ********************************************/      
	public byte[] Encrytor(String str) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// Initialize the Cipher object according to the key, ENCRYPT_MODE represents the encryption mode
		c.init(Cipher.ENCRYPT_MODE, deskey);
		byte[] src = str.getBytes();
		// Encrypt, save the result into cipherByte
		cipherByte = c.doFinal(src);
		return cipherByte;
	}
	
	/* ********************************************
	 * method name   : Decryptor
	 * description : decrypt the string
	 * @return       : byte[]
	 * @param        : @param buff
	 * @param        : @return
	 * @param        : @throws InvalidKeyException
	 * @param        : @throws IllegalBlockSizeException
	 * @param        : @throws BadPaddingException
	 * modified      : ncc ,  2017-12-19
	 * @see          :
	 * ********************************************/      
	public byte[] Decryptor(byte[] buff) throws InvalidKeyException,
			IllegalBlockSizeException, BadPaddingException {
		// Initialize the Cipher object according to the key, DECRYPT_MODE represents the encryption mode
		c.init(Cipher.DECRYPT_MODE, deskey);
		cipherByte = c.doFinal(buff);
		return cipherByte;
	}

	/**
	 * @param args
	 * @throws NoSuchPaddingException
	 * @throws NoSuchAlgorithmException
	 * @throws BadPaddingException
	 * @throws IllegalBlockSizeException
	 * @throws InvalidKeyException
	 */
	public static void main(String[] args) throws Exception {
		DcDES de1 = new DcDES();
		String msg = "Welcome to the House of Grass!";
		byte[] encontent = de1.Encrytor(msg);
		byte[] decontent = de1.Decryptor(encontent);
		System.out.println("Plaintext is: " + msg);
		System.out.println("After encryption:" + new String(encontent));
		System.out.println("After decryption:" + new String(decontent));
	}

}