package com.android.util;

import java.math.BigInteger;  
import java.security.MessageDigest;  
import java.security.SecureRandom;  
  
import javax.crypto.Cipher;  
import javax.crypto.KeyGenerator;  
import javax.crypto.spec.SecretKeySpec;  
  
import sun.misc.BASE64Decoder;  
import sun.misc.BASE64Encoder;  

  
/** 
 * 编码工具类 
 * 1.将byte[]转为各种进制的字符串 
 * 2.base 64 encode 
 * 3.base 64 decode 
 * 4.获取byte[]的md5值 
 * 5.获取字符串md5值 
 * 6.结合base64实现md5加密 
 * 7.AES加密 
 * 8.AES加密为base 64 code 
 * 9.AES解密 
 * 10.将base 64 code AES解密 
 * @author uikoo9 
 * @version 0.0.7.20140601 
 */  
public class QEncodeUtil {  
      
    public static void main(String[] args) throws Exception {  
        String content = "我爱你";  
        System.out.println("加密前：" + content);  
  
        String key = "123456";  
        System.out.println("加密密钥和解密密钥：" + key);  
          
        String encrypt = aesEncrypt(content, key);  
        System.out.println("加密后：" + encrypt);  
          
        String decrypt = aesDecrypt(encrypt, key);  
        System.out.println("解密后：" + decrypt);  
    }  
      
    /** 
     * 将byte[]转为各种进制的字符串 
     * @param bytes byte[] 
     * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制 
     * @return 转换后的字符串 
     */  
    public static String binary(byte[] bytes, int radix){  
        return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数  
    }  
      
    /** 
     * base 64 encode 
     * @param bytes 待编码的byte[] 
     * @return 编码后的base 64 code 
     */  
    public static String base64Encode(byte[] bytes){  
        return new BASE64Encoder().encode(bytes);  
    }  
      
    /** 
     * base 64 decode 
     * @param base64Code 待解码的base 64 code 
     * @return 解码后的byte[] 
     * @throws Exception 
     */  
    public static byte[] base64Decode(String base64Code) throws Exception{
        return StringUtil.isNullString(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);  
    }  
      
    /** 
     * 获取byte[]的md5值 
     * @param bytes byte[] 
     * @return md5 
     * @throws Exception 
     */  
    public static byte[] md5(byte[] bytes) throws Exception {  
        MessageDigest md = MessageDigest.getInstance("MD5");  
        md.update(bytes);  
          
        return md.digest();  
    }  
      
    /** 
     * 获取字符串md5值 
     * @param msg  
     * @return md5 
     * @throws Exception 
     */  
    public static byte[] md5(String msg) throws Exception {  
        return StringUtil.isNullString(msg) ? null : md5(msg.getBytes());  
    }  
      
    /** 
     * 结合base64实现md5加密 
     * @param msg 待加密字符串 
     * @return 获取md5后转为base64 
     * @throws Exception 
     */  
    public static String md5Encrypt(String msg) throws Exception{  
        return StringUtil.isNullString(msg) ? null : base64Encode(md5(msg));  
    }  
      
    /** 
     * AES加密 
     * @param content 待加密的内容 
     * @param encryptKey 加密密钥 
     * @return 加密后的byte[] 
     * @throws Exception 
     */  
    public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {  
        KeyGenerator kgen = KeyGenerator.getInstance("AES");  
        kgen.init(128, new SecureRandom(encryptKey.getBytes()));  
  
        Cipher cipher = Cipher.getInstance("AES");  
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));  
          
        return cipher.doFinal(content.getBytes("utf-8"));  
    }  
      
    /** 
     * AES加密为base 64 code 
     * @param content 待加密的内容 
     * @param encryptKey 加密密钥 
     * @return 加密后的base 64 code 
     * @throws Exception 
     */  
    public static String aesEncrypt(String content, String encryptKey) throws Exception {  
        return base64Encode(aesEncryptToBytes(content, encryptKey));  
    }  
      
    /** 
     * AES解密 
     * @param encryptBytes 待解密的byte[] 
     * @param decryptKey 解密密钥 
     * @return 解密后的String 
     * @throws Exception 
     */  
    public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {  
        KeyGenerator kgen = KeyGenerator.getInstance("AES");  
        kgen.init(128, new SecureRandom(decryptKey.getBytes()));  
          
        Cipher cipher = Cipher.getInstance("AES");  
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));  
        byte[] decryptBytes = cipher.doFinal(encryptBytes);  
          
        return new String(decryptBytes);  
    }  
      
    /** 
     * 将base 64 code AES解密 
     * @param encryptStr 待解密的base 64 code 
     * @param decryptKey 解密密钥 
     * @return 解密后的string 
     * @throws Exception 
     */  
    public static String aesDecrypt(String encryptStr, String decryptKey) throws Exception {  
        return StringUtil.isNullString(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);  
    }  
      
}