import org.apache.commons.codec.binary.Base64;  import org.apache.commons.codec.digest.DigestUtils;    import org.junit.Test;  /**   * @author liuxinglanyue   * @since 2010-12-21  * @version $Revision$   */    public class MD5Test   {        //被加密的文字串        static final String TARGET = "changeme";              /*      * 不可逆算法  MD5      */      @Test      public void Md5()      {          String str = DigestUtils.md5Hex(TARGET);          print("md5Hex:     "+str);      }      /*      * 不可逆算法  SHA1      */      @Test      public void Sha1()      {          String str = DigestUtils.shaHex(TARGET);          print("shaHex:     "+str);          str = DigestUtils.sha256Hex(TARGET);          print("sha256Hex:  "+str);          str = DigestUtils.sha384Hex(TARGET);          print("sha384Hex:  "+str);          str = DigestUtils.sha512Hex(TARGET);          print("sha512Hex:  "+str);      }            /*      * 可逆算法  BASE64      */      @Test      public void Base64()      {          //加密          byte[] b = Base64.encodeBase64(TARGET.getBytes(), true);          String str = new String(b);          print("BASE64:     "+str);                    //解密          byte[] b1 = Base64.decodeBase64(str);          print("解密之后内容为：  "+new String(b1));      }      public void print(Object obj)      {          System.out.println(obj);      }  }

参考文档：http://liuxinglanyue.iteye.com/blog/848654