Java加密类

主要是用于加密，加密是可逆的，可以加密也可以解密。

package com.gxtuan.util;    import java.security.NoSuchAlgorithmException;    import javax.crypto.Cipher;  import javax.crypto.NoSuchPaddingException;  import javax.crypto.spec.IvParameterSpec;  import javax.crypto.spec.SecretKeySpec;    public class JiaMi {     private String iv = "feie91o96t2q2p0p";   private IvParameterSpec ivspec;   private SecretKeySpec keyspec;   private Cipher cipher;      private String SecretKey = "8d0bfe2fb0311fd7";      public JiaMi()   {    ivspec = new IvParameterSpec(iv.getBytes());      keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");        try {     cipher = Cipher.getInstance("AES/CBC/NoPadding");    } catch (NoSuchAlgorithmException e) {     // TODO Auto-generated catch block     e.printStackTrace();    } catch (NoSuchPaddingException e) {     // TODO Auto-generated catch block     e.printStackTrace();    }   }      public byte[] encrypt(String text) throws Exception   {    if(text == null || text.length() == 0)     throw new Exception("Empty string");        byte[] encrypted = null;      try {     cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);       encrypted = cipher.doFinal(padString(text).getBytes());    } catch (Exception e)    {        throw new Exception("[encrypt] " + e.getMessage());    }        return encrypted;   }      public byte[] decrypt(String code) throws Exception   {    if(code == null || code.length() == 0)     throw new Exception("Empty string");        byte[] decrypted = null;      try {     cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);          decrypted = cipher.doFinal(hexToBytes(code));    } catch (Exception e)    {     throw new Exception("[decrypt] " + e.getMessage());    }    return decrypted;   }           public static String bytesToHex(byte[] data)   {    if (data==null)    {     return null;    }        int len = data.length;    String str = "";    for (int i=0; i<len; i++) {     if ((data[i]&0xFF)<16)      str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF);     else      str = str + java.lang.Integer.toHexString(data[i]&0xFF);    }    return str;   }          public static byte[] hexToBytes(String str) {    if (str==null) {     return null;    } else if (str.length() < 2) {     return null;    } else {     int len = str.length() / 2;     byte[] buffer = new byte[len];     for (int i=0; i<len; i++) {      buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);     }     return buffer;    }   }           private static String padString(String source)   {     char paddingChar = ' ';     int size = 16;     int x = source.length() % size;     int padLength = size - x;       for (int i = 0; i < padLength; i++)     {      source += paddingChar;     }       return source;   }  }  //使用方法：  //加密  String   encrypted = JiaMi.bytesToHex(jm.encrypt("你要加密的内容"));  //解密    String decrypted = new String(JiaMi.decrypt(encrypted));