| /* |
| * ==================================================================== |
| * 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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| |
| package org.apache.hc.core5.http.impl.io; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import org.apache.hc.core5.http.ConnectionClosedException; |
| import org.apache.hc.core5.http.StreamClosedException; |
| import org.apache.hc.core5.http.io.SessionInputBuffer; |
| import org.apache.hc.core5.util.Args; |
| |
| /** |
| * Input stream that cuts off after a defined number of bytes. This class |
| * is used to receive content of HTTP messages where the end of the content |
| * entity is determined by the value of the {@code Content-Length header}. |
| * Entities transferred using this stream can be maximum {@link Long#MAX_VALUE} |
| * long. |
| * <p> |
| * Note that this class NEVER closes the underlying stream, even when |
| * {@link #close()} gets called. Instead, it will read until the "end" of |
| * its limit on close, which allows for the seamless execution of subsequent |
| * HTTP 1.1 requests, while not requiring the client to remember to read the |
| * entire contents of the response. |
| * |
| * |
| * @since 4.0 |
| */ |
| public class ContentLengthInputStream extends InputStream { |
| |
| private static final int BUFFER_SIZE = 2048; |
| |
| private final SessionInputBuffer buffer; |
| private final InputStream inputStream; |
| |
| /** |
| * The maximum number of bytes that can be read from the stream. Subsequent |
| * read operations will return -1. |
| */ |
| private final long contentLength; |
| |
| /** The current position */ |
| private long pos; |
| |
| /** True if the stream is closed. */ |
| private boolean closed; |
| |
| /** |
| * Default constructor. |
| * |
| * @param buffer Session input buffer |
| * @param inputStream Input stream |
| * @param contentLength The maximum number of bytes that can be read from |
| * the stream. Subsequent read operations will return -1. |
| */ |
| public ContentLengthInputStream(final SessionInputBuffer buffer, final InputStream inputStream, final long contentLength) { |
| super(); |
| this.buffer = Args.notNull(buffer, "Session input buffer"); |
| this.inputStream = Args.notNull(inputStream, "Input stream"); |
| this.contentLength = Args.notNegative(contentLength, "Content length"); |
| } |
| |
| /** |
| * <p>Reads until the end of the known length of content.</p> |
| * |
| * <p>Does NOT close the underlying stream, but instead leaves it |
| * primed to parse the next response.</p> |
| * @throws IOException If an IO problem occurs. |
| */ |
| @Override |
| public void close() throws IOException { |
| if (!closed) { |
| try { |
| if (pos < contentLength) { |
| final byte[] buffer = new byte[BUFFER_SIZE]; |
| while (read(buffer) >= 0) { |
| // keep reading |
| } |
| } |
| } finally { |
| // close after above so that we don't throw an exception trying |
| // to read after closed! |
| closed = true; |
| } |
| } |
| } |
| |
| @Override |
| public int available() throws IOException { |
| final int len = this.buffer.length(); |
| return Math.min(len, (int) (this.contentLength - this.pos)); |
| } |
| |
| /** |
| * Read the next byte from the stream |
| * @return The next byte or -1 if the end of stream has been reached. |
| * @throws IOException If an IO problem occurs |
| * @see java.io.InputStream#read() |
| */ |
| @Override |
| public int read() throws IOException { |
| if (closed) { |
| throw new StreamClosedException(); |
| } |
| |
| if (pos >= contentLength) { |
| return -1; |
| } |
| final int b = this.buffer.read(this.inputStream); |
| if (b == -1) { |
| if (pos < contentLength) { |
| throw new ConnectionClosedException( |
| "Premature end of Content-Length delimited message body (expected: %d; received: %d)", |
| contentLength, pos); |
| } |
| } else { |
| pos++; |
| } |
| return b; |
| } |
| |
| /** |
| * Does standard {@link InputStream#read(byte[], int, int)} behavior, but |
| * also notifies the watcher when the contents have been consumed. |
| * |
| * @param b The byte array to fill. |
| * @param off Start filling at this position. |
| * @param len The number of bytes to attempt to read. |
| * @return The number of bytes read, or -1 if the end of content has been |
| * reached. |
| * |
| * @throws java.io.IOException Should an error occur on the wrapped stream. |
| */ |
| @Override |
| public int read(final byte[] b, final int off, final int len) throws java.io.IOException { |
| if (closed) { |
| throw new StreamClosedException(); |
| } |
| |
| if (pos >= contentLength) { |
| return -1; |
| } |
| |
| int chunk = len; |
| if (pos + len > contentLength) { |
| chunk = (int) (contentLength - pos); |
| } |
| final int count = this.buffer.read(b, off, chunk, this.inputStream); |
| if (count == -1 && pos < contentLength) { |
| throw new ConnectionClosedException( |
| "Premature end of Content-Length delimited message body (expected: %d; received: %d)", |
| contentLength, pos); |
| } |
| if (count > 0) { |
| pos += count; |
| } |
| return count; |
| } |
| |
| |
| /** |
| * Read more bytes from the stream. |
| * @param b The byte array to put the new data in. |
| * @return The number of bytes read into the buffer. |
| * @throws IOException If an IO problem occurs |
| * @see java.io.InputStream#read(byte[]) |
| */ |
| @Override |
| public int read(final byte[] b) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| /** |
| * Skips and discards a number of bytes from the input stream. |
| * @param n The number of bytes to skip. |
| * @return The actual number of bytes skipped. ≤ 0 if no bytes |
| * are skipped. |
| * @throws IOException If an error occurs while skipping bytes. |
| * @see InputStream#skip(long) |
| */ |
| @Override |
| public long skip(final long n) throws IOException { |
| if (n <= 0) { |
| return 0; |
| } |
| final byte[] buffer = new byte[BUFFER_SIZE]; |
| // make sure we don't skip more bytes than are |
| // still available |
| long remaining = Math.min(n, this.contentLength - this.pos); |
| // skip and keep track of the bytes actually skipped |
| long count = 0; |
| while (remaining > 0) { |
| final int readLen = read(buffer, 0, (int)Math.min(BUFFER_SIZE, remaining)); |
| if (readLen == -1) { |
| break; |
| } |
| count += readLen; |
| remaining -= readLen; |
| } |
| return count; |
| } |
| } |