| /* |
| * Copyright (c) 1994, 2019, 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.Objects; |
| |
| /** |
| * This abstract class is the superclass of all classes representing |
| * an output stream of bytes. An output stream accepts output bytes |
| * and sends them to some sink. |
| * <p> |
| * Applications that need to define a subclass of |
| * {@code OutputStream} must always provide at least a method |
| * that writes one byte of output. |
| * |
| * @author Arthur van Hoff |
| * @see java.io.BufferedOutputStream |
| * @see java.io.ByteArrayOutputStream |
| * @see java.io.DataOutputStream |
| * @see java.io.FilterOutputStream |
| * @see java.io.InputStream |
| * @see java.io.OutputStream#write(int) |
| * @since 1.0 |
| */ |
| public abstract class OutputStream implements Closeable, Flushable { |
| /** |
| * Constructor for subclasses to call. |
| */ |
| public OutputStream() {} |
| |
| /** |
| * Returns a new {@code OutputStream} which discards all 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 write(int)}, {@code |
| * write(byte[])}, and {@code write(byte[], int, int)} methods do nothing. |
| * After the stream has been closed, these methods all throw {@code |
| * IOException}. |
| * |
| * <p> The {@code flush()} method does nothing. |
| * |
| * @return an {@code OutputStream} which discards all bytes |
| * |
| * @since 11 |
| */ |
| public static OutputStream nullOutputStream() { |
| return new OutputStream() { |
| private volatile boolean closed; |
| |
| private void ensureOpen() throws IOException { |
| if (closed) { |
| throw new IOException("Stream closed"); |
| } |
| } |
| |
| @Override |
| public void write(int b) throws IOException { |
| ensureOpen(); |
| } |
| |
| @Override |
| public void write(byte b[], int off, int len) throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| ensureOpen(); |
| } |
| |
| @Override |
| public void close() { |
| closed = true; |
| } |
| }; |
| } |
| |
| /** |
| * Writes the specified byte to this output stream. The general |
| * contract for {@code write} is that one byte is written |
| * to the output stream. The byte to be written is the eight |
| * low-order bits of the argument {@code b}. The 24 |
| * high-order bits of {@code b} are ignored. |
| * <p> |
| * Subclasses of {@code OutputStream} must provide an |
| * implementation for this method. |
| * |
| * @param b the {@code byte}. |
| * @throws IOException if an I/O error occurs. In particular, |
| * an {@code IOException} may be thrown if the |
| * output stream has been closed. |
| */ |
| public abstract void write(int b) throws IOException; |
| |
| /** |
| * Writes {@code b.length} bytes from the specified byte array |
| * to this output stream. The general contract for {@code write(b)} |
| * is that it should have exactly the same effect as the call |
| * {@code write(b, 0, b.length)}. |
| * |
| * @param b the data. |
| * @throws IOException if an I/O error occurs. |
| * @see java.io.OutputStream#write(byte[], int, int) |
| */ |
| public void write(byte b[]) throws IOException { |
| write(b, 0, b.length); |
| } |
| |
| /** |
| * Writes {@code len} bytes from the specified byte array |
| * starting at offset {@code off} to this output stream. |
| * The general contract for {@code write(b, off, len)} is that |
| * some of the bytes in the array {@code b} are written to the |
| * output stream in order; element {@code b[off]} is the first |
| * byte written and {@code b[off+len-1]} is the last byte written |
| * by this operation. |
| * <p> |
| * The {@code write} method of {@code OutputStream} calls |
| * the write method of one argument on each of the bytes to be |
| * written out. Subclasses are encouraged to override this method and |
| * provide a more efficient implementation. |
| * <p> |
| * If {@code b} is {@code null}, a |
| * {@code NullPointerException} is thrown. |
| * <p> |
| * If {@code off} is negative, or {@code len} is negative, or |
| * {@code off+len} is greater than the length of the array |
| * {@code b}, then an {@code IndexOutOfBoundsException} is thrown. |
| * |
| * @param b the data. |
| * @param off the start offset in the data. |
| * @param len the number of bytes to write. |
| * @throws IOException if an I/O error occurs. In particular, |
| * an {@code IOException} is thrown if the output |
| * stream is closed. |
| */ |
| public void write(byte b[], int off, int len) throws IOException { |
| Objects.checkFromIndexSize(off, len, b.length); |
| // len == 0 condition implicitly handled by loop bounds |
| for (int i = 0 ; i < len ; i++) { |
| write(b[off + i]); |
| } |
| } |
| |
| /** |
| * Flushes this output stream and forces any buffered output bytes |
| * to be written out. The general contract of {@code flush} is |
| * that calling it is an indication that, if any bytes previously |
| * written have been buffered by the implementation of the output |
| * stream, such bytes should immediately be written to their |
| * intended destination. |
| * <p> |
| * If the intended destination of this stream is an abstraction provided by |
| * the underlying operating system, for example a file, then flushing the |
| * stream guarantees only that bytes previously written to the stream are |
| * passed to the operating system for writing; it does not guarantee that |
| * they are actually written to a physical device such as a disk drive. |
| * <p> |
| * The {@code flush} method of {@code OutputStream} does nothing. |
| * |
| * @throws IOException if an I/O error occurs. |
| */ |
| public void flush() throws IOException { |
| } |
| |
| /** |
| * Closes this output stream and releases any system resources |
| * associated with this stream. The general contract of {@code close} |
| * is that it closes the output stream. A closed stream cannot perform |
| * output operations and cannot be reopened. |
| * <p> |
| * The {@code close} method of {@code OutputStream} does nothing. |
| * |
| * @throws IOException if an I/O error occurs. |
| */ |
| public void close() throws IOException { |
| } |
| |
| } |
