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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one or more
      3  * contributor license agreements.  See the NOTICE file distributed with
      4  * this work for additional information regarding copyright ownership.
      5  * The ASF licenses this file to You under the Apache License, Version 2.0
      6  * (the "License"); you may not use this file except in compliance with
      7  * the License.  You may obtain a copy of the License at
      8  *
      9  *     http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  * Unless required by applicable law or agreed to in writing, software
     12  * distributed under the License is distributed on an "AS IS" BASIS,
     13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  * See the License for the specific language governing permissions and
     15  * limitations under the License.
     16  */
     17 
     18 package java.util.zip;
     19 
     20 /**
     21  * The interface common to checksum classes such as {@link Adler32} and {@link CRC32}.
     22  */
     23 public interface Checksum {
     24 
     25     /**
     26      * Returns the current calculated checksum value.
     27      *
     28      * @return the checksum.
     29      */
     30     public long getValue();
     31 
     32     /**
     33      * Resets the checksum value applied before beginning calculations on a new
     34      * stream of data.
     35      */
     36     public void reset();
     37 
     38     /**
     39      * Updates the checksum with the given bytes.
     40      *
     41      * @param buf
     42      *            the byte array from which to read the bytes.
     43      * @param off
     44      *            the initial position in {@code buf} to read the bytes from.
     45      * @param nbytes
     46      *            the number of bytes to read from {@code buf}.
     47      */
     48     public void update(byte[] buf, int off, int nbytes);
     49 
     50     /**
     51      * Updates the checksum value with the given byte.
     52      *
     53      * @param val
     54      *            the byte to update the checksum with.
     55      */
     56     public void update(int val);
     57 }
     58