| /* |
| * Copyright (c) 1994, 2021, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.io; |
| |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.Objects; |
| |
| /** |
| * This abstract class is the superclass of all classes representing |
| * an input stream of bytes. |
| * |
| * <p> Applications that need to define a subclass of {@code InputStream} |
| * must always provide a method that returns the next byte of input. |
| * |
| * @author Arthur van Hoff |
| * @see java.io.BufferedInputStream |
| * @see java.io.ByteArrayInputStream |
| * @see java.io.DataInputStream |
| * @see java.io.FilterInputStream |
| * @see java.io.InputStream#read() |
| * @see java.io.OutputStream |
| * @see java.io.PushbackInputStream |
| * @since 1.0 |
| */ |
| public abstract class InputStream implements Closeable { |
| |
| // MAX_SKIP_BUFFER_SIZE is used to determine the maximum buffer size to |
| // use when skipping. |
| private static final int MAX_SKIP_BUFFER_SIZE = 2048; |
| |
| private static final int DEFAULT_BUFFER_SIZE = 8192; |
| |
| /** |
| * Constructor for subclasses to call. |
| */ |
| public InputStream() {} |
| |
| /** |
| * Returns a new {@code InputStream} that reads no bytes. The returned |
| * stream is initially open. The stream is closed by calling the |
| * {@code close()} method. Subsequent calls to {@code close()} have no |
| * effect. |
| * |
| * <p> While the stream is open, the {@code available()}, {@code read()}, |
| * {@code read(byte[])}, {@code read(byte[], int, int)}, |
| * {@code readAllBytes()}, {@code readNBytes(byte[], int, int)}, |
| * {@code readNBytes(int)}, {@code skip(long)}, {@code skipNBytes(long)}, |
| * and {@code transferTo()} methods all behave as if end of stream has been |
| * reached. After the stream has been closed, these methods all throw |
| * {@code IOException}. |
| * |
| * <p> The {@code markSupported()} method returns {@code false}. The |
| * {@code mark()} method does nothing, and the {@code reset()} method |
| * throws {@code IOException}. |
| * |
| * @return an {@code InputStream} which contains no bytes |
| * |
| * @since 11 |
| */ |
| public static InputStream nullInputStream() { |
| return new InputStream() { |
| private volatile boolean closed; |
| |
| private void ensureOpen() throws IOException { |
| if (closed) { |
| throw new IOException("Stream closed"); |
| } |
| } |
| |
| @Override |
| public int available () throws IOException { |
| ensureOpen(); |
| return 0; |
| } |
| |
| @Override |
| public int read() throws IOException { |
| ensureOpen(); |
| return -1; |
| } |
| |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| if (len == 0) { |
| return 0; |
| } |
| ensureOpen(); |
| return -1; |
| } |
| |
| @Override |
| public byte[] readAllBytes() throws IOException { |
| ensureOpen(); |
| return new byte[0]; |
| } |
| |
| @Override |
| public int readNBytes(byte[] b, int off, int len) |
| throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| ensureOpen(); |
| return 0; |
| } |
| |
| @Override |
| public byte[] readNBytes(int len) throws IOException { |
| if (len < 0) { |
| throw new IllegalArgumentException("len < 0"); |
| } |
| ensureOpen(); |
| return new byte[0]; |
| } |
| |
| @Override |
| public long skip(long n) throws IOException { |
| ensureOpen(); |
| return 0L; |
| } |
| |
| @Override |
| public void skipNBytes(long n) throws IOException { |
| ensureOpen(); |
| if (n > 0) { |
| throw new EOFException(); |
| } |
| } |
| |
| @Override |
| public long transferTo(OutputStream out) throws IOException { |
| Objects.requireNonNull(out); |
| ensureOpen(); |
| return 0L; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| closed = true; |
| } |
| }; |
| } |
| |
| /** |
| * Reads the next byte of data from the input stream. The value byte is |
| * returned as an {@code int} in the range {@code 0} to |
| * {@code 255}. If no byte is available because the end of the stream |
| * has been reached, the value {@code -1} is returned. This method |
| * blocks until input data is available, the end of the stream is detected, |
| * or an exception is thrown. |
| * |
| * <p> A subclass must provide an implementation of this method. |
| * |
| * @return the next byte of data, or {@code -1} if the end of the |
| * stream is reached. |
| * @throws IOException if an I/O error occurs. |
| */ |
| public abstract int read() throws IOException; |
| |
| /** |
| * Reads some number of bytes from the input stream and stores them into |
| * the buffer array {@code b}. The number of bytes actually read is |
| * returned as an integer. This method blocks until input data is |
| * available, end of file is detected, or an exception is thrown. |
| * |
| * <p> If the length of {@code b} is zero, then no bytes are read and |
| * {@code 0} is returned; otherwise, there is an attempt to read at |
| * least one byte. If no byte is available because the stream is at the |
| * end of the file, the value {@code -1} is returned; otherwise, at |
| * least one byte is read and stored into {@code b}. |
| * |
| * <p> The first byte read is stored into element {@code b[0]}, the |
| * next one into {@code b[1]}, and so on. The number of bytes read is, |
| * at most, equal to the length of {@code b}. Let <i>k</i> be the |
| * number of bytes actually read; these bytes will be stored in elements |
| * {@code b[0]} through {@code b[}<i>k</i>{@code -1]}, |
| * leaving elements {@code b[}<i>k</i>{@code ]} through |
| * {@code b[b.length-1]} unaffected. |
| * |
| * <p> The {@code read(b)} method for class {@code InputStream} |
| * has the same effect as: <pre>{@code read(b, 0, b.length) }</pre> |
| * |
| * @param b the buffer into which the data is read. |
| * @return the total number of bytes read into the buffer, or |
| * {@code -1} if there is no more data because the end of |
| * the stream has been reached. |
| * @throws IOException If the first byte cannot be read for any reason |
| * other than the end of the file, if the input stream has been |
| * closed, or if some other I/O error occurs. |
| * @throws NullPointerException if {@code b} is {@code null}. |
| * @see java.io.InputStream#read(byte[], int, int) |
| */ |
| public int read(byte b[]) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| /** |
| * Reads up to {@code len} bytes of data from the input stream into |
| * an array of bytes. An attempt is made to read as many as |
| * {@code len} bytes, but a smaller number may be read. |
| * The number of bytes actually read is returned as an integer. |
| * |
| * <p> This method blocks until input data is available, end of file is |
| * detected, or an exception is thrown. |
| * |
| * <p> If {@code len} is zero, then no bytes are read and |
| * {@code 0} is returned; otherwise, there is an attempt to read at |
| * least one byte. If no byte is available because the stream is at end of |
| * file, the value {@code -1} is returned; otherwise, at least one |
| * byte is read and stored into {@code b}. |
| * |
| * <p> The first byte read is stored into element {@code b[off]}, the |
| * next one into {@code b[off+1]}, and so on. The number of bytes read |
| * is, at most, equal to {@code len}. Let <i>k</i> be the number of |
| * bytes actually read; these bytes will be stored in elements |
| * {@code b[off]} through {@code b[off+}<i>k</i>{@code -1]}, |
| * leaving elements {@code b[off+}<i>k</i>{@code ]} through |
| * {@code b[off+len-1]} unaffected. |
| * |
| * <p> In every case, elements {@code b[0]} through |
| * {@code b[off-1]} and elements {@code b[off+len]} through |
| * {@code b[b.length-1]} are unaffected. |
| * |
| * <p> The {@code read(b, off, len)} method |
| * for class {@code InputStream} simply calls the method |
| * {@code read()} repeatedly. If the first such call results in an |
| * {@code IOException}, that exception is returned from the call to |
| * the {@code read(b,} {@code off,} {@code len)} method. If |
| * any subsequent call to {@code read()} results in a |
| * {@code IOException}, the exception is caught and treated as if it |
| * were end of file; the bytes read up to that point are stored into |
| * {@code b} and the number of bytes read before the exception |
| * occurred is returned. The default implementation of this method blocks |
| * until the requested amount of input data {@code len} has been read, |
| * end of file is detected, or an exception is thrown. Subclasses are |
| * encouraged to provide a more efficient implementation of this method. |
| * |
| * @param b the buffer into which the data is read. |
| * @param off the start offset in array {@code b} |
| * at which the data is written. |
| * @param len the maximum number of bytes to read. |
| * @return the total number of bytes read into the buffer, or |
| * {@code -1} if there is no more data because the end of |
| * the stream has been reached. |
| * @throws IOException If the first byte cannot be read for any reason |
| * other than end of file, or if the input stream has been closed, |
| * or if some other I/O error occurs. |
| * @throws NullPointerException If {@code b} is {@code null}. |
| * @throws IndexOutOfBoundsException If {@code off} is negative, |
| * {@code len} is negative, or {@code len} is greater than |
| * {@code b.length - off} |
| * @see java.io.InputStream#read() |
| */ |
| public int read(byte b[], int off, int len) throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| if (len == 0) { |
| return 0; |
| } |
| |
| int c = read(); |
| if (c == -1) { |
| return -1; |
| } |
| b[off] = (byte)c; |
| |
| int i = 1; |
| try { |
| for (; i < len ; i++) { |
| c = read(); |
| if (c == -1) { |
| break; |
| } |
| b[off + i] = (byte)c; |
| } |
| } catch (IOException ee) { |
| } |
| return i; |
| } |
| |
| /** |
| * The maximum size of array to allocate. |
| * Some VMs reserve some header words in an array. |
| * Attempts to allocate larger arrays may result in |
| * OutOfMemoryError: Requested array size exceeds VM limit |
| */ |
| private static final int MAX_BUFFER_SIZE = Integer.MAX_VALUE - 8; |
| |
| /** |
| * Reads all remaining bytes from the input stream. This method blocks until |
| * all remaining bytes have been read and end of stream is detected, or an |
| * exception is thrown. This method does not close the input stream. |
| * |
| * <p> When this stream reaches end of stream, further invocations of this |
| * method will return an empty byte array. |
| * |
| * <p> Note that this method is intended for simple cases where it is |
| * convenient to read all bytes into a byte array. It is not intended for |
| * reading input streams with large amounts of data. |
| * |
| * <p> The behavior for the case where the input stream is <i>asynchronously |
| * closed</i>, or the thread interrupted during the read, is highly input |
| * stream specific, and therefore not specified. |
| * |
| * <p> If an I/O error occurs reading from the input stream, then it may do |
| * so after some, but not all, bytes have been read. Consequently the input |
| * stream may not be at end of stream and may be in an inconsistent state. |
| * It is strongly recommended that the stream be promptly closed if an I/O |
| * error occurs. |
| * |
| * @implSpec |
| * This method invokes {@link #readNBytes(int)} with a length of |
| * {@link Integer#MAX_VALUE}. |
| * |
| * @return a byte array containing the bytes read from this input stream |
| * @throws IOException if an I/O error occurs |
| * @throws OutOfMemoryError if an array of the required size cannot be |
| * allocated. |
| * |
| * @since 9 |
| */ |
| public byte[] readAllBytes() throws IOException { |
| return readNBytes(Integer.MAX_VALUE); |
| } |
| |
| /** |
| * Reads up to a specified number of bytes from the input stream. This |
| * method blocks until the requested number of bytes has been read, end |
| * of stream is detected, or an exception is thrown. This method does not |
| * close the input stream. |
| * |
| * <p> The length of the returned array equals the number of bytes read |
| * from the stream. If {@code len} is zero, then no bytes are read and |
| * an empty byte array is returned. Otherwise, up to {@code len} bytes |
| * are read from the stream. Fewer than {@code len} bytes may be read if |
| * end of stream is encountered. |
| * |
| * <p> When this stream reaches end of stream, further invocations of this |
| * method will return an empty byte array. |
| * |
| * <p> Note that this method is intended for simple cases where it is |
| * convenient to read the specified number of bytes into a byte array. The |
| * total amount of memory allocated by this method is proportional to the |
| * number of bytes read from the stream which is bounded by {@code len}. |
| * Therefore, the method may be safely called with very large values of |
| * {@code len} provided sufficient memory is available. |
| * |
| * <p> The behavior for the case where the input stream is <i>asynchronously |
| * closed</i>, or the thread interrupted during the read, is highly input |
| * stream specific, and therefore not specified. |
| * |
| * <p> If an I/O error occurs reading from the input stream, then it may do |
| * so after some, but not all, bytes have been read. Consequently the input |
| * stream may not be at end of stream and may be in an inconsistent state. |
| * It is strongly recommended that the stream be promptly closed if an I/O |
| * error occurs. |
| * |
| * @implNote |
| * The number of bytes allocated to read data from this stream and return |
| * the result is bounded by {@code 2*(long)len}, inclusive. |
| * |
| * @param len the maximum number of bytes to read |
| * @return a byte array containing the bytes read from this input stream |
| * @throws IllegalArgumentException if {@code length} is negative |
| * @throws IOException if an I/O error occurs |
| * @throws OutOfMemoryError if an array of the required size cannot be |
| * allocated. |
| * |
| * @since 11 |
| */ |
| public byte[] readNBytes(int len) throws IOException { |
| if (len < 0) { |
| throw new IllegalArgumentException("len < 0"); |
| } |
| |
| List<byte[]> bufs = null; |
| byte[] result = null; |
| int total = 0; |
| int remaining = len; |
| int n; |
| do { |
| byte[] buf = new byte[Math.min(remaining, DEFAULT_BUFFER_SIZE)]; |
| int nread = 0; |
| |
| // read to EOF which may read more or less than buffer size |
| while ((n = read(buf, nread, |
| Math.min(buf.length - nread, remaining))) > 0) { |
| nread += n; |
| remaining -= n; |
| } |
| |
| if (nread > 0) { |
| if (MAX_BUFFER_SIZE - total < nread) { |
| throw new OutOfMemoryError("Required array size too large"); |
| } |
| if (nread < buf.length) { |
| buf = Arrays.copyOfRange(buf, 0, nread); |
| } |
| total += nread; |
| if (result == null) { |
| result = buf; |
| } else { |
| if (bufs == null) { |
| bufs = new ArrayList<>(); |
| bufs.add(result); |
| } |
| bufs.add(buf); |
| } |
| } |
| // if the last call to read returned -1 or the number of bytes |
| // requested have been read then break |
| } while (n >= 0 && remaining > 0); |
| |
| if (bufs == null) { |
| if (result == null) { |
| return new byte[0]; |
| } |
| return result.length == total ? |
| result : Arrays.copyOf(result, total); |
| } |
| |
| result = new byte[total]; |
| int offset = 0; |
| remaining = total; |
| for (byte[] b : bufs) { |
| int count = Math.min(b.length, remaining); |
| System.arraycopy(b, 0, result, offset, count); |
| offset += count; |
| remaining -= count; |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Reads the requested number of bytes from the input stream into the given |
| * byte array. This method blocks until {@code len} bytes of input data have |
| * been read, end of stream is detected, or an exception is thrown. The |
| * number of bytes actually read, possibly zero, is returned. This method |
| * does not close the input stream. |
| * |
| * <p> In the case where end of stream is reached before {@code len} bytes |
| * have been read, then the actual number of bytes read will be returned. |
| * When this stream reaches end of stream, further invocations of this |
| * method will return zero. |
| * |
| * <p> If {@code len} is zero, then no bytes are read and {@code 0} is |
| * returned; otherwise, there is an attempt to read up to {@code len} bytes. |
| * |
| * <p> The first byte read is stored into element {@code b[off]}, the next |
| * one in to {@code b[off+1]}, and so on. The number of bytes read is, at |
| * most, equal to {@code len}. Let <i>k</i> be the number of bytes actually |
| * read; these bytes will be stored in elements {@code b[off]} through |
| * {@code b[off+}<i>k</i>{@code -1]}, leaving elements {@code b[off+}<i>k</i> |
| * {@code ]} through {@code b[off+len-1]} unaffected. |
| * |
| * <p> The behavior for the case where the input stream is <i>asynchronously |
| * closed</i>, or the thread interrupted during the read, is highly input |
| * stream specific, and therefore not specified. |
| * |
| * <p> If an I/O error occurs reading from the input stream, then it may do |
| * so after some, but not all, bytes of {@code b} have been updated with |
| * data from the input stream. Consequently the input stream and {@code b} |
| * may be in an inconsistent state. It is strongly recommended that the |
| * stream be promptly closed if an I/O error occurs. |
| * |
| * @param b the byte array into which the data is read |
| * @param off the start offset in {@code b} at which the data is written |
| * @param len the maximum number of bytes to read |
| * @return the actual number of bytes read into the buffer |
| * @throws IOException if an I/O error occurs |
| * @throws NullPointerException if {@code b} is {@code null} |
| * @throws IndexOutOfBoundsException If {@code off} is negative, {@code len} |
| * is negative, or {@code len} is greater than {@code b.length - off} |
| * |
| * @since 9 |
| */ |
| public int readNBytes(byte[] b, int off, int len) throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| |
| int n = 0; |
| while (n < len) { |
| int count = read(b, off + n, len - n); |
| if (count < 0) |
| break; |
| n += count; |
| } |
| return n; |
| } |
| |
| /** |
| * Skips over and discards {@code n} bytes of data from this input |
| * stream. The {@code skip} method may, for a variety of reasons, end |
| * up skipping over some smaller number of bytes, possibly {@code 0}. |
| * This may result from any of a number of conditions; reaching end of file |
| * before {@code n} bytes have been skipped is only one possibility. |
| * The actual number of bytes skipped is returned. If {@code n} is |
| * negative, the {@code skip} method for class {@code InputStream} always |
| * returns 0, and no bytes are skipped. Subclasses may handle the negative |
| * value differently. |
| * |
| * <p> The {@code skip} method implementation of this class creates a |
| * byte array and then repeatedly reads into it until {@code n} bytes |
| * have been read or the end of the stream has been reached. Subclasses are |
| * encouraged to provide a more efficient implementation of this method. |
| * For instance, the implementation may depend on the ability to seek. |
| * |
| * @param n the number of bytes to be skipped. |
| * @return the actual number of bytes skipped which might be zero. |
| * @throws IOException if an I/O error occurs. |
| * @see java.io.InputStream#skipNBytes(long) |
| */ |
| public long skip(long n) throws IOException { |
| long remaining = n; |
| int nr; |
| |
| if (n <= 0) { |
| return 0; |
| } |
| |
| int size = (int)Math.min(MAX_SKIP_BUFFER_SIZE, remaining); |
| byte[] skipBuffer = new byte[size]; |
| while (remaining > 0) { |
| nr = read(skipBuffer, 0, (int)Math.min(size, remaining)); |
| if (nr < 0) { |
| break; |
| } |
| remaining -= nr; |
| } |
| |
| return n - remaining; |
| } |
| |
| /** |
| * Skips over and discards exactly {@code n} bytes of data from this input |
| * stream. If {@code n} is zero, then no bytes are skipped. |
| * If {@code n} is negative, then no bytes are skipped. |
| * Subclasses may handle the negative value differently. |
| * |
| * <p> This method blocks until the requested number of bytes has been |
| * skipped, end of file is reached, or an exception is thrown. |
| * |
| * <p> If end of stream is reached before the stream is at the desired |
| * position, then an {@code EOFException} is thrown. |
| * |
| * <p> If an I/O error occurs, then the input stream may be |
| * in an inconsistent state. It is strongly recommended that the |
| * stream be promptly closed if an I/O error occurs. |
| * |
| * @implNote |
| * Subclasses are encouraged to provide a more efficient implementation |
| * of this method. |
| * |
| * @implSpec |
| * If {@code n} is zero or negative, then no bytes are skipped. |
| * If {@code n} is positive, the default implementation of this method |
| * invokes {@link #skip(long) skip()} repeatedly with its parameter equal |
| * to the remaining number of bytes to skip until the requested number |
| * of bytes has been skipped or an error condition occurs. If at any |
| * point the return value of {@code skip()} is negative or greater than the |
| * remaining number of bytes to be skipped, then an {@code IOException} is |
| * thrown. If {@code skip()} ever returns zero, then {@link #read()} is |
| * invoked to read a single byte, and if it returns {@code -1}, then an |
| * {@code EOFException} is thrown. Any exception thrown by {@code skip()} |
| * or {@code read()} will be propagated. |
| * |
| * @param n the number of bytes to be skipped. |
| * @throws EOFException if end of stream is encountered before the |
| * stream can be positioned {@code n} bytes beyond its position |
| * when this method was invoked. |
| * @throws IOException if the stream cannot be positioned properly or |
| * if an I/O error occurs. |
| * @see java.io.InputStream#skip(long) |
| * |
| * @since 12 |
| */ |
| public void skipNBytes(long n) throws IOException { |
| while (n > 0) { |
| long ns = skip(n); |
| if (ns > 0 && ns <= n) { |
| // adjust number to skip |
| n -= ns; |
| } else if (ns == 0) { // no bytes skipped |
| // read one byte to check for EOS |
| if (read() == -1) { |
| throw new EOFException(); |
| } |
| // one byte read so decrement number to skip |
| n--; |
| } else { // skipped negative or too many bytes |
| throw new IOException("Unable to skip exactly"); |
| } |
| } |
| } |
| |
| /** |
| * Returns an estimate of the number of bytes that can be read (or skipped |
| * over) from this input stream without blocking, which may be 0, or 0 when |
| * end of stream is detected. The read might be on the same thread or |
| * another thread. A single read or skip of this many bytes will not block, |
| * but may read or skip fewer bytes. |
| * |
| * <p> Note that while some implementations of {@code InputStream} will |
| * return the total number of bytes in the stream, many will not. It is |
| * never correct to use the return value of this method to allocate |
| * a buffer intended to hold all data in this stream. |
| * |
| * <p> A subclass's implementation of this method may choose to throw an |
| * {@link IOException} if this input stream has been closed by invoking the |
| * {@link #close()} method. |
| * |
| * <p> The {@code available} method of {@code InputStream} always returns |
| * {@code 0}. |
| * |
| * <p> This method should be overridden by subclasses. |
| * |
| * @return an estimate of the number of bytes that can be read (or |
| * skipped over) from this input stream without blocking or |
| * {@code 0} when it reaches the end of the input stream. |
| * @throws IOException if an I/O error occurs. |
| */ |
| public int available() throws IOException { |
| return 0; |
| } |
| |
| /** |
| * Closes this input stream and releases any system resources associated |
| * with the stream. |
| * |
| * <p> The {@code close} method of {@code InputStream} does |
| * nothing. |
| * |
| * @throws IOException if an I/O error occurs. |
| */ |
| public void close() throws IOException {} |
| |
| /** |
| * Marks the current position in this input stream. A subsequent call to |
| * the {@code reset} method repositions this stream at the last marked |
| * position so that subsequent reads re-read the same bytes. |
| * |
| * <p> The {@code readlimit} arguments tells this input stream to |
| * allow that many bytes to be read before the mark position gets |
| * invalidated. |
| * |
| * <p> The general contract of {@code mark} is that, if the method |
| * {@code markSupported} returns {@code true}, the stream somehow |
| * remembers all the bytes read after the call to {@code mark} and |
| * stands ready to supply those same bytes again if and whenever the method |
| * {@code reset} is called. However, the stream is not required to |
| * remember any data at all if more than {@code readlimit} bytes are |
| * read from the stream before {@code reset} is called. |
| * |
| * <p> Marking a closed stream should not have any effect on the stream. |
| * |
| * <p> The {@code mark} method of {@code InputStream} does |
| * nothing. |
| * |
| * @param readlimit the maximum limit of bytes that can be read before |
| * the mark position becomes invalid. |
| * @see java.io.InputStream#reset() |
| */ |
| public synchronized void mark(int readlimit) {} |
| |
| /** |
| * Repositions this stream to the position at the time the |
| * {@code mark} method was last called on this input stream. |
| * |
| * <p> The general contract of {@code reset} is: |
| * |
| * <ul> |
| * <li> If the method {@code markSupported} returns |
| * {@code true}, then: |
| * |
| * <ul><li> If the method {@code mark} has not been called since |
| * the stream was created, or the number of bytes read from the stream |
| * since {@code mark} was last called is larger than the argument |
| * to {@code mark} at that last call, then an |
| * {@code IOException} might be thrown. |
| * |
| * <li> If such an {@code IOException} is not thrown, then the |
| * stream is reset to a state such that all the bytes read since the |
| * most recent call to {@code mark} (or since the start of the |
| * file, if {@code mark} has not been called) will be resupplied |
| * to subsequent callers of the {@code read} method, followed by |
| * any bytes that otherwise would have been the next input data as of |
| * the time of the call to {@code reset}. </ul> |
| * |
| * <li> If the method {@code markSupported} returns |
| * {@code false}, then: |
| * |
| * <ul><li> The call to {@code reset} may throw an |
| * {@code IOException}. |
| * |
| * <li> If an {@code IOException} is not thrown, then the stream |
| * is reset to a fixed state that depends on the particular type of the |
| * input stream and how it was created. The bytes that will be supplied |
| * to subsequent callers of the {@code read} method depend on the |
| * particular type of the input stream. </ul></ul> |
| * |
| * <p>The method {@code reset} for class {@code InputStream} |
| * does nothing except throw an {@code IOException}. |
| * |
| * @throws IOException if this stream has not been marked or if the |
| * mark has been invalidated. |
| * @see java.io.InputStream#mark(int) |
| * @see java.io.IOException |
| */ |
| public synchronized void reset() throws IOException { |
| throw new IOException("mark/reset not supported"); |
| } |
| |
| /** |
| * Tests if this input stream supports the {@code mark} and |
| * {@code reset} methods. Whether or not {@code mark} and |
| * {@code reset} are supported is an invariant property of a |
| * particular input stream instance. The {@code markSupported} method |
| * of {@code InputStream} returns {@code false}. |
| * |
| * @return {@code true} if this stream instance supports the mark |
| * and reset methods; {@code false} otherwise. |
| * @see java.io.InputStream#mark(int) |
| * @see java.io.InputStream#reset() |
| */ |
| public boolean markSupported() { |
| return false; |
| } |
| |
| /** |
| * Reads all bytes from this input stream and writes the bytes to the |
| * given output stream in the order that they are read. On return, this |
| * input stream will be at end of stream. This method does not close either |
| * stream. |
| * <p> |
| * This method may block indefinitely reading from the input stream, or |
| * writing to the output stream. The behavior for the case where the input |
| * and/or output stream is <i>asynchronously closed</i>, or the thread |
| * interrupted during the transfer, is highly input and output stream |
| * specific, and therefore not specified. |
| * <p> |
| * If an I/O error occurs reading from the input stream or writing to the |
| * output stream, then it may do so after some bytes have been read or |
| * written. Consequently the input stream may not be at end of stream and |
| * one, or both, streams may be in an inconsistent state. It is strongly |
| * recommended that both streams be promptly closed if an I/O error occurs. |
| * |
| * @param out the output stream, non-null |
| * @return the number of bytes transferred |
| * @throws IOException if an I/O error occurs when reading or writing |
| * @throws NullPointerException if {@code out} is {@code null} |
| * |
| * @since 9 |
| */ |
| public long transferTo(OutputStream out) throws IOException { |
| Objects.requireNonNull(out, "out"); |
| long transferred = 0; |
| byte[] buffer = new byte[DEFAULT_BUFFER_SIZE]; |
| int read; |
| while ((read = this.read(buffer, 0, DEFAULT_BUFFER_SIZE)) >= 0) { |
| out.write(buffer, 0, read); |
| transferred += read; |
| } |
| return transferred; |
| } |
| } |