/*
 * Copyright 2014 - 2020 Rafael Winterhalter
 *
 * 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 net.bytebuddy.utility;

import net.bytebuddy.build.HashCodeAndEqualsPlugin;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

A utility for draining the contents of an InputStream into a byte array.
/** * A utility for draining the contents of an {@link java.io.InputStream} into a {@code byte} array. */
@HashCodeAndEqualsPlugin.Enhance public class StreamDrainer {
The default size of the buffer for draining a stream.
/** * The default size of the buffer for draining a stream. */
public static final int DEFAULT_BUFFER_SIZE = 1024;
A default instance using the DEFAULT_BUFFER_SIZE.
/** * A default instance using the {@link StreamDrainer#DEFAULT_BUFFER_SIZE}. */
public static final StreamDrainer DEFAULT = new StreamDrainer();
A convenience constant referring to the value representing the end of a stream.
/** * A convenience constant referring to the value representing the end of a stream. */
private static final int END_OF_STREAM = -1;
A convenience constant referring to the value representing the start of a stream.
/** * A convenience constant referring to the value representing the start of a stream. */
private static final int FROM_BEGINNING = 0;
The buffer size for reading from a given stream.
/** * The buffer size for reading from a given stream. */
private final int bufferSize;
Creates a stream drainer with the default buffer size.
/** * Creates a stream drainer with the default buffer size. */
public StreamDrainer() { this(DEFAULT_BUFFER_SIZE); }
Creates a stream drainer with the given buffer size.
Params:
  • bufferSize – The buffer size for reading from a given stream.
/** * Creates a stream drainer with the given buffer size. * * @param bufferSize The buffer size for reading from a given stream. */
public StreamDrainer(int bufferSize) { this.bufferSize = bufferSize; }
Drains an input stream into a byte array. The given input stream is not closed.
Params:
  • inputStream – The input stream to drain.
Throws:
Returns:A byte array containing the content of the input stream.
/** * Drains an input stream into a byte array. The given input stream is not closed. * * @param inputStream The input stream to drain. * @return A byte array containing the content of the input stream. * @throws IOException If the stream reading causes an error. */
public byte[] drain(InputStream inputStream) throws IOException { List<byte[]> previousBytes = new ArrayList<byte[]>(); byte[] currentArray = new byte[bufferSize]; int currentIndex = 0; int currentRead; do { currentRead = inputStream.read(currentArray, currentIndex, bufferSize - currentIndex); currentIndex += currentRead > 0 ? currentRead : 0; if (currentIndex == bufferSize) { previousBytes.add(currentArray); currentArray = new byte[bufferSize]; currentIndex = 0; } } while (currentRead != END_OF_STREAM); byte[] result = new byte[previousBytes.size() * bufferSize + currentIndex]; int arrayIndex = 0; for (byte[] previousByte : previousBytes) { System.arraycopy(previousByte, FROM_BEGINNING, result, arrayIndex++ * bufferSize, bufferSize); } System.arraycopy(currentArray, FROM_BEGINNING, result, arrayIndex * bufferSize, currentIndex); return result; } }