| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.nutch.crawl; |
| |
| import org.apache.hadoop.io.MD5Hash; |
| import org.apache.nutch.parse.Parse; |
| import org.apache.nutch.protocol.Content; |
| |
| /** |
| * Implementation of a page signature. It calculates an MD5 hash of the textual |
| * content of a page. In case there is no content, it calculates a hash from the |
| * page's URL. |
| */ |
| public class TextMD5Signature extends Signature { |
| |
| Signature fallback = new MD5Signature(); |
| |
| public byte[] calculate(Content content, Parse parse) { |
| String text = parse.getText(); |
| |
| if (text == null || text.length() == 0) { |
| return fallback.calculate(content, parse); |
| } |
| |
| return MD5Hash.digest(text).getDigest(); |
| } |
| } |