ChecksumFields.java

/*
 * Copyright 2007  T-Rank AS
 * 
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
 * 
 * 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 no.trank.openpipe.step;

import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.List;

import no.trank.openpipe.api.MultiInputFieldPipelineStep;
import no.trank.openpipe.api.PipelineException;
import no.trank.openpipe.api.PipelineStepStatus;
import no.trank.openpipe.api.document.AnnotatedField;
import no.trank.openpipe.api.document.Document;
import no.trank.openpipe.config.BeanValidator;
import no.trank.openpipe.config.annotation.NotEmpty;
import static no.trank.openpipe.util.HexUtil.toHexString;

/**
 * @version $Revision$
 */
public class ChecksumFields extends MultiInputFieldPipelineStep {
   private static final Charset CHARSET = Charset.forName("UTF-8");
   @NotEmpty
   private String outField;
   @NotEmpty
   private String algorithm = "MD5";
   private MessageDigest messageDigest;

   @Override
   public PipelineStepStatus execute(Document doc) throws PipelineException {
      messageDigest.reset();
      executeInputFields(doc);
      doc.setFieldValue(outField, toHexString(messageDigest.digest()));
      return PipelineStepStatus.DEFAULT;
   }

   @Override
   protected void process(Document doc, String fieldName, List<AnnotatedField> fieldValues) throws PipelineException {
      for (AnnotatedField fieldValue : fieldValues) {
         messageDigest.update(fieldValue.getValue().getBytes(CHARSET));
      }
   }

   public String getOutField() {
      return outField;
   }

   public void setOutField(String outField) {
      this.outField = outField;
   }

   public String getAlgorithm() {
      return algorithm;
   }

   public void setAlgorithm(String algorithm) {
      this.algorithm = algorithm;
   }

   @Override
   public String getRevision() {
      return "$Revision$";
   }

   @Override
   public void prepare() throws PipelineException {
      BeanValidator.validate(this);
      try {
         messageDigest = MessageDigest.getInstance(algorithm);
      } catch (NoSuchAlgorithmException e) {
         throw new PipelineException(e);
      }
   }

   @Override
   public void finish(boolean success) {
      messageDigest = null;
   }
}