| /* |
| * Copyright (c) 1994, 2017, 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; |
| |
| /** |
| * This class is the superclass of all classes that filter output |
| * streams. These streams sit on top of an already existing output |
| * stream (the <i>underlying</i> output stream) which it uses as its |
| * basic sink of data, but possibly transforming the data along the |
| * way or providing additional functionality. |
| * <p> |
| * The class <code>FilterOutputStream</code> itself simply overrides |
| * all methods of <code>OutputStream</code> with versions that pass |
| * all requests to the underlying output stream. Subclasses of |
| * <code>FilterOutputStream</code> may further override some of these |
| * methods as well as provide additional methods and fields. |
| * |
| * @author Jonathan Payne |
| * @since 1.0 |
| */ |
| public class FilterOutputStream extends OutputStream { |
| /** |
| * The underlying output stream to be filtered. |
| */ |
| protected OutputStream out; |
| |
| /** |
| * Whether the stream is closed; implicitly initialized to false. |
| */ |
| private volatile boolean closed; |
| |
| /** |
| * Object used to prevent a race on the 'closed' instance variable. |
| */ |
| private final Object closeLock = new Object(); |
| |
| /** |
| * Creates an output stream filter built on top of the specified |
| * underlying output stream. |
| * |
| * @param out the underlying output stream to be assigned to |
| * the field {@code this.out} for later use, or |
| * <code>null</code> if this instance is to be |
| * created without an underlying stream. |
| */ |
| public FilterOutputStream(OutputStream out) { |
| this.out = out; |
| } |
| |
| /** |
| * Writes the specified <code>byte</code> to this output stream. |
| * <p> |
| * The <code>write</code> method of <code>FilterOutputStream</code> |
| * calls the <code>write</code> method of its underlying output stream, |
| * that is, it performs {@code out.write(b)}. |
| * <p> |
| * Implements the abstract {@code write} method of {@code OutputStream}. |
| * |
| * @param b the <code>byte</code>. |
| * @exception IOException if an I/O error occurs. |
| */ |
| @Override |
| public void write(int b) throws IOException { |
| out.write(b); |
| } |
| |
| /** |
| * Writes <code>b.length</code> bytes to this output stream. |
| * <p> |
| * The <code>write</code> method of <code>FilterOutputStream</code> |
| * calls its <code>write</code> method of three arguments with the |
| * arguments <code>b</code>, <code>0</code>, and |
| * <code>b.length</code>. |
| * <p> |
| * Note that this method does not call the one-argument |
| * <code>write</code> method of its underlying output stream with |
| * the single argument <code>b</code>. |
| * |
| * @param b the data to be written. |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterOutputStream#write(byte[], int, int) |
| */ |
| @Override |
| public void write(byte b[]) throws IOException { |
| write(b, 0, b.length); |
| } |
| |
| /** |
| * Writes <code>len</code> bytes from the specified |
| * <code>byte</code> array starting at offset <code>off</code> to |
| * this output stream. |
| * <p> |
| * The <code>write</code> method of <code>FilterOutputStream</code> |
| * calls the <code>write</code> method of one argument on each |
| * <code>byte</code> to output. |
| * <p> |
| * Note that this method does not call the <code>write</code> method |
| * of its underlying output stream with the same arguments. Subclasses |
| * of <code>FilterOutputStream</code> should provide a more efficient |
| * implementation of this method. |
| * |
| * @param b the data. |
| * @param off the start offset in the data. |
| * @param len the number of bytes to write. |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterOutputStream#write(int) |
| */ |
| @Override |
| public void write(byte b[], int off, int len) throws IOException { |
| if ((off | len | (b.length - (len + off)) | (off + len)) < 0) |
| throw new IndexOutOfBoundsException(); |
| |
| 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 to the stream. |
| * <p> |
| * The <code>flush</code> method of <code>FilterOutputStream</code> |
| * calls the <code>flush</code> method of its underlying output stream. |
| * |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterOutputStream#out |
| */ |
| @Override |
| public void flush() throws IOException { |
| out.flush(); |
| } |
| |
| /** |
| * Closes this output stream and releases any system resources |
| * associated with the stream. |
| * <p> |
| * When not already closed, the {@code close} method of {@code |
| * FilterOutputStream} calls its {@code flush} method, and then |
| * calls the {@code close} method of its underlying output stream. |
| * |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.FilterOutputStream#flush() |
| * @see java.io.FilterOutputStream#out |
| */ |
| @Override |
| public void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| synchronized (closeLock) { |
| if (closed) { |
| return; |
| } |
| closed = true; |
| } |
| |
| Throwable flushException = null; |
| try { |
| flush(); |
| } catch (Throwable e) { |
| flushException = e; |
| throw e; |
| } finally { |
| if (flushException == null) { |
| out.close(); |
| } else { |
| try { |
| out.close(); |
| } catch (Throwable closeException) { |
| // evaluate possible precedence of flushException over closeException |
| if ((flushException instanceof ThreadDeath) && |
| !(closeException instanceof ThreadDeath)) { |
| flushException.addSuppressed(closeException); |
| throw (ThreadDeath) flushException; |
| } |
| |
| if (flushException != closeException) { |
| closeException.addSuppressed(flushException); |
| } |
| |
| throw closeException; |
| } |
| } |
| } |
| } |
| } |