| /* | |
| * Copyright (c) 1994, 2024, 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 jdk.internal.util.ArraysSupport; | |
| 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 = 16384; | |
| /** | |
| * 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. | |
| * | |
| * @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. | |
| * | |
| * @implSpec | |
| * The {@code read(b)} method for class {@code InputStream} | |
| * has the same effect as: | |
| * {@snippet lang=java : | |
| * read(b, 0, b.length) | |
| * } | |
| * | |
| * @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. | |
| * | |
| * @implSpec | |
| * 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 | |
| */ | |
| private static final int MAX_BUFFER_SIZE = ArraysSupport.SOFT_MAX_ARRAY_LENGTH; | |
| /** | |
| * 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. | |
| * | |
| * @implSpec | |
| * 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. | |
| * | |
| * @implSpec | |
| * The {@code available} method of {@code InputStream} always returns | |
| * {@code 0}. | |
| * | |
| * @apiNote | |
| * 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. | |
| * | |
| * @implSpec | |
| * 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. | |
| * | |
| * @implSpec | |
| * 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 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> | |
| * | |
| * @implSpec | |
| * 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 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. | |
| * | |
| * @implSpec | |
| * 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 the total number of bytes transferred is greater than {@linkplain | |
| * Long#MAX_VALUE}, then {@code Long.MAX_VALUE} will be returned. | |
| * <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); | |
| if (transferred < Long.MAX_VALUE) { | |
| try { | |
| transferred = Math.addExact(transferred, read); | |
| } catch (ArithmeticException ignore) { | |
| transferred = Long.MAX_VALUE; | |
| } | |
| } | |
| } | |
| return transferred; | |
| } | |
| } |