java Encryption&Decryption

The encryption class:

package cn.com.smartcost.qy.util;

import java.security.Key;
import java.security.Security;  

import javax.crypto.Cipher;  

/**
 * encrypt and decryption
 * @author wangfeng
 * @since 2013-4-27 15:50:26
 * @version 1.0
 *
 */
public class EncryptionDecryption {
    private static String strDefaultKey = "wfkey";  

  //encrypt
    private Cipher encryptCipher = null;  

  // decryption
    private Cipher decryptCipher = null;  

    /**
     * byte array to hexadecimal
     * @param arrB
     * @return 16
     * @throws Exception
     */
    public static String byteArr2HexStr(byte[] arrB) throws Exception{
        int bLen = arrB.length;
        //
        StringBuffer strBuffer = new StringBuffer(bLen*2);
        for(int i=0; i != bLen; ++i){
            int intTmp = arrB[i];
            //
            while(intTmp < 0){
                intTmp = intTmp + 256;//
            }
            //
            if(intTmp < 16){
                strBuffer.append("0");
            }
            strBuffer.append(Integer.toString(intTmp,16));
        }
        return strBuffer.toString();
    }  

    /**
     * hex to byte array
     * @param hexStr
     * @return
     * @throws Exception
     */
    public static byte[] hexStr2ByteArr(String hexStr) throws Exception{
        byte[] arrB = hexStr.getBytes();
        int bLen = arrB.length;
        byte[] arrOut = new byte[bLen/2];
        for(int i=0; i<bLen; i = i+2){
            String strTmp = new String(arrB,i,2);
            arrOut[i/2] = (byte)Integer.parseInt(strTmp,16);
        }
        return arrOut;
    }  

    /**
     * encrypt
     * @throws Exception
     */
    public EncryptionDecryption() throws Exception {
        this(strDefaultKey);
    }  

    /**
     * encryption
     * @param strKey
     * @throws Exception
     */
       @SuppressWarnings("restriction")
    public EncryptionDecryption(String strKey) throws Exception {
            Security.addProvider(new com.sun.crypto.provider.SunJCE());
            Key key = getKey(strKey.getBytes());  

            encryptCipher = Cipher.getInstance("DES");
            encryptCipher.init(Cipher.ENCRYPT_MODE, key);  

            decryptCipher = Cipher.getInstance("DES");
            decryptCipher.init(Cipher.DECRYPT_MODE, key);
        }  

    /**
     * encrypt
     * @param arrB
     * @return
     * @throws Exception
     */
    public byte[] encrypt(byte[] arrB) throws Exception{
        return encryptCipher.doFinal(arrB);
    }  

    /**
     * encrypt
     * @param strIn
     * @return
     * @throws Exception
     */
    public String encrypt(String strIn) throws Exception{
        return byteArr2HexStr(encrypt(strIn.getBytes()));
    }  

    /**
     * decrypt
     * @param arrB
     * @return
     * @throws Exception
     */
    public byte[] decrypt(byte[] arrB) throws Exception{
        return decryptCipher.doFinal(arrB);
    }  

    /**
     * decrypt
     * @param strIn
     * @return
     * @throws Exception
     */
    public String decrypt(String strIn) throws Exception{
        try{
            return new String(decrypt(hexStr2ByteArr(strIn)));
        }catch (Exception e) {
            return "";
        }
    }  

    /**
     * get the key
     * @param arrBTmp
     * @return
     * @throws Exception
     */
    private Key getKey(byte[] arrBTmp) throws Exception{
        byte[] arrB = new byte[8]; //
        for(int i=0; i<arrBTmp.length && i < arrB.length; ++i){
            arrB[i] = arrBTmp[i];
        }  

        //
        Key key = new javax.crypto.spec.SecretKeySpec(arrB,"DES");
        return key;
    }  

}

　　Attention:

This class nees a jar:sunjce_provider.jar. u can download it from here: http://pan.baidu.com/s/1ntqkU4h

To use:

private EncryptionDecryption des = new  EncryptionDecryption("wang");
//encrypt
String password = "123456";
password = des.encrypt(password);
//decrypt
password =des.decrypt(password);