aes加密

package com.m.billingplug.util;

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

/**
 * AES加密类
 * @author mhx
 *
 */
public class AesUtil {

    /**
     * 日志输出标签
     */
    private static final String TAG = "AesUtil";
    /**
     * AES加密方式
     */
    private static final String AES = "AES";
    /**
     * key
     */
    public static final String KEY = "mhx";

    /**
     * 加密
     * @param encryptStr
     * @return
     */
    private 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 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);
    }

    /**
     * 
     * @param b
     * @return
     */
    private 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 byte[] hex2byte(byte[] b) {
        if ((b.length % 2) != 0)
            throw new IllegalArgumentException("非法数据异常!");
        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
     * @param data
     * @return
     * @throws Exception
     */
    public String getDesString(String data, String CRYPT_KEY) {
        try {
            return new String(decrypt(hex2byte(data.getBytes()), CRYPT_KEY));
        } catch (Exception e) {
            e.printStackTrace();
            LogUtil.i(TAG, "解密出错");
        }
        return null;
    }

    /**
     * 加密
     * @param data
     * @return
     * @throws Exception
     */
    public String getEncString(String data, String CRYPT_KEY) {
        try {
            return byte2hex(encrypt(data.getBytes(), CRYPT_KEY));
        } catch (Exception e) {
            e.printStackTrace();
            LogUtil.i(TAG, "加密出错");
        }
        return null;
    }
}