Java Digest digest(MessageDigest digest, InputStream data)

Description

Read through an InputStream and returns the digest for the data

License

Apache License

Parameter

Parameter	Description
digest	The MessageDigest to use (e.g. MD5)
data	Data to digest

Exception

Parameter	Description
IOException	On error reading from the stream

Return

MD5 digest

Declaration

private static byte[] digest(MessageDigest digest, InputStream data) throws IOException 

Method Source Code

//package com.java2s;
/*/* w  ww  .j a v a2s  . c om*/
 * 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.
 */

import java.io.IOException;
import java.io.InputStream;

import java.security.MessageDigest;

public class Main {
    private static final int STREAM_BUFFER_LENGTH = 1024;

    /**
     * Read through an InputStream and returns the digest for the data
     * 
     * @param digest The MessageDigest to use (e.g. MD5)
     * @param data Data to digest
     * @return MD5 digest
     * @throws IOException On error reading from the stream
     */
    private static byte[] digest(MessageDigest digest, InputStream data) throws IOException {
        byte[] buffer = new byte[STREAM_BUFFER_LENGTH];
        int read = data.read(buffer, 0, STREAM_BUFFER_LENGTH);

        while (read > -1) {
            digest.update(buffer, 0, read);
            read = data.read(buffer, 0, STREAM_BUFFER_LENGTH);
        }

        return digest.digest();
    }
}

Related

1. digest(final java.security.MessageDigest messageDigest, final java.nio.ByteBuffer data)
2. digest(final String algorithm, final byte[] bytes)
3. digest(final String password)
4. digest(InputStream input, String algorithm)
5. digest(InputStream is, String digestAlgorithm)
6. digest(MessageDigest method, File f)
7. digest(Serializable object)
8. digest(String alg, byte[] plainByte)
9. digest(String algorithm, byte[] bytes)