/*
 * Copyright 2002-2018 the original author or authors.
 *
 * 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
 *
 *      https://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.
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package org.springframework.util;

import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;

Extension of InputStream that allows for optimized implementations of message digesting.
Author:Craig Andrews
Since:4.2
/** * Extension of {@link java.io.InputStream} that allows for optimized * implementations of message digesting. * * @author Craig Andrews * @since 4.2 */
abstract class UpdateMessageDigestInputStream extends InputStream {
Update the message digest with the rest of the bytes in this stream.

Using this method is more optimized since it avoids creating new byte arrays for each call.

Params:
  • messageDigest – the message digest to update
Throws:
/** * Update the message digest with the rest of the bytes in this stream. * <p>Using this method is more optimized since it avoids creating new * byte arrays for each call. * @param messageDigest the message digest to update * @throws IOException when propagated from {@link #read()} */
public void updateMessageDigest(MessageDigest messageDigest) throws IOException { int data; while ((data = read()) != -1) { messageDigest.update((byte) data); } }
Update the message digest with the next len bytes in this stream.

Using this method is more optimized since it avoids creating new byte arrays for each call.

Params:
  • messageDigest – the message digest to update
  • len – how many bytes to read from this stream and use to update the message digest
Throws:
/** * Update the message digest with the next len bytes in this stream. * <p>Using this method is more optimized since it avoids creating new * byte arrays for each call. * @param messageDigest the message digest to update * @param len how many bytes to read from this stream and use to update the message digest * @throws IOException when propagated from {@link #read()} */
public void updateMessageDigest(MessageDigest messageDigest, int len) throws IOException { int data; int bytesRead = 0; while (bytesRead < len && (data = read()) != -1) { messageDigest.update((byte) data); bytesRead++; } } }