加密相关类

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

/**
 * ASC加密解密辅助类.
 * 
 * @author admin
 * @version 1.0.0
 * 
 */
public class AesUtil {
	private static final String AES = "AES";
	private static final String CRYPT_KEY = "YUUAtestYUUAtest";

	/**
	 * 加密.
	 * 
	 * @param src
	 * @param key
	 * @return
	 * @throws Exception
	 */
	private static byte[] encrypt(byte[] src, String key) throws Exception {
		Cipher cipher = Cipher.getInstance(AES);
		SecretKeySpec securekey = new SecretKeySpec(key.getBytes(), AES);
		cipher.init(Cipher.ENCRYPT_MODE, securekey);
		
		return cipher.doFinal(src);
	}

	/**
	 * 解密.
	 * 
	 * @param decryptStr
	 * @return
	 * @throws Exception
	 */
	private static byte[] decrypt(byte[] src, String key) throws Exception {
		Cipher cipher = Cipher.getInstance(AES);
		SecretKeySpec securekey = new SecretKeySpec(key.getBytes(), AES);
		cipher.init(Cipher.DECRYPT_MODE, securekey);
		
		return cipher.doFinal(src);
	}

	/**
	 * 二行制转十六进制字符串.
	 * 
	 * @param b
	 * @return
	 */
	private static String byte2hex(byte[] b) {
		String hs = "";
		String stmp = "";
		
		for (int n = 0; n < b.length; n++) {
			stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));
			
			if (stmp.length() == 1) {
				hs = hs + "0" + stmp;
			} 
			else{
				hs = hs + stmp;
			}
		}
		
		return hs.toUpperCase();
	}

	private static byte[] hex2byte(byte[] b) {
		if ((b.length % 2) != 0) {
			throw new IllegalArgumentException("长度不是偶数");
		}
		
		byte[] b2 = new byte[b.length / 2];
		
		for (int n = 0; n < b.length; n += 2) {
			String item = new String(b, n, 2);
			b2[n / 2] = (byte) Integer.parseInt(item, 16);
		}
		
		return b2;
	}

	/**
	* 解密(供外部调用).
	* 
	* @param data
	* @return
	* @throws Exception
	*/
	public final static String decrypt(String data) {
		try {			
			return new String(decrypt(hex2byte(data.getBytes()), CRYPT_KEY));
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
		
		return null;
	}

	/**
	* 加密(供外部调用).
	* 
	* @param data
	* @return
	* @throws Exception
	*/
	public final static String encrypt(String data) {
		try {
			return byte2hex(encrypt(data.getBytes(), CRYPT_KEY));
		} 
		catch (Exception e) {
			e.printStackTrace();
		}
		
		return null;
	}
}