Android 运用des算法

import java.security.Key;import java.security.spec.AlgorithmParameterSpec;import javax.crypto.Cipher;import javax.crypto.SecretKeyFactory;import javax.crypto.spec.DESKeySpec;import javax.crypto.spec.IvParameterSpec;import android.util.Base64;public class DesUtils { public static final String ALGORITHM_DES = "DES/CBC/PKCS5Padding"; /**  * DES算法，加密  * @param data 待加密字符串  * @param key 加密私钥，长度不能够小于8位  * @return 加密后的字节数组，一般结合Base64编码使用  * @throws CryptException 异常  */ public static String encode(String key, String data) throws Exception {  return encode(key, data.getBytes()); } /**  * DES算法，加密  * @param data  待加密字符串  * @param key  加密私钥，长度不能够小于8位  * @return 加密后的字节数组，一般结合Base64编码使用  * @throws CryptException  *             异常  */ private static String encode(String key, byte[] data) throws Exception {  try {   DESKeySpec dks = new DESKeySpec(key.getBytes());   SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");   // key的长度不能够小于8位字节   Key secretKey = keyFactory.generateSecret(dks);   Cipher cipher = Cipher.getInstance(ALGORITHM_DES);   IvParameterSpec iv = new IvParameterSpec("12345678".getBytes());   AlgorithmParameterSpec paramSpec = iv;   cipher.init(Cipher.ENCRYPT_MODE, secretKey, paramSpec);   byte[] bytes = cipher.doFinal(data);   return Base64.encodeToString(bytes, 0);  } catch (Exception e) {   throw new Exception(e);  } } /**  * DES算法，解密  * @param data  待解密字符串  * @param key 解密私钥，长度不能够小于8位  * @return 解密后的字节数组  * @throws Exception  异常  */ private static byte[] decode(String key, byte[] data) throws Exception {  try {   DESKeySpec dks = new DESKeySpec(key.getBytes());   SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");   // key的长度不能够小于8位字节   Key secretKey = keyFactory.generateSecret(dks);   Cipher cipher = Cipher.getInstance(ALGORITHM_DES);   IvParameterSpec iv = new IvParameterSpec("12345678".getBytes());   AlgorithmParameterSpec paramSpec = iv;   cipher.init(Cipher.DECRYPT_MODE, secretKey, paramSpec);   return cipher.doFinal(data);  } catch (Exception e) {   throw new Exception(e);  } }  /**  * 解密.  * @param key  * @param data  * @return  * @throws Exception  */ public static String decode(String key, String data) {  byte[] datas;  String value = null;  try {   if (System.getProperty("os.name") != null     && (System.getProperty("os.name").equalsIgnoreCase("sunos") || System       .getProperty("os.name").equalsIgnoreCase("linux"))) {    datas = decode(key, Base64.decode(data, 0));   } else {    datas = decode(key, Base64.decode(data, 0));   }   value = new String(datas);  } catch (Exception e) {   value = "";  }  return value; }}