/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.core.api.util;

 import org.apache.commons.codec.binary.Base64;

 import org.kuali.rice.core.api.exception.RiceRuntimeException;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.ObjectOutput;

 import java.io.ObjectOutputStream;

 import java.io.UnsupportedEncodingException;

 import java.security.GeneralSecurityException;

 import java.security.MessageDigest;

 /**

  * A utility class for generating checksum values from Serializable objects.

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public final class ChecksumUtils {

     /**

          * Creates a checksum for the given object which must be serializable.

          *

          * @param object the serializable object for which to calculate the checksum

      * 

          * @return A checksum value for the object.

          */

         public static String calculateChecksum(Object object) {

                 ByteArrayOutputStream bos = new ByteArrayOutputStream();

         ObjectOutput out = null;

         try {

             out = new ObjectOutputStream(bos);

             out.writeObject(object);

         } catch (IOException e) {

             throw new RiceRuntimeException(e);

         } finally {

             try {

                 out.close();

             } catch (IOException e) {}

         }

         try {

             MessageDigest md = MessageDigest.getInstance("SHA-1");

             return new String( Base64.encodeBase64(md.digest(bos.toByteArray())), "UTF-8");

         } catch( GeneralSecurityException ex ) {

                 throw new RiceRuntimeException(ex);

         } catch( UnsupportedEncodingException ex ) {

                 throw new RiceRuntimeException(ex);

         }

         }

     @SuppressWarnings("unused")

     private ChecksumUtils() {

         throw new UnsupportedOperationException("Should never be executed.");

     }

 }