| /* |
| * 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. |
| * |
| */ |
| |
| package org.apache.tools.ant.util; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| /** |
| * Manages a set of <code>OutputStream</code>s to |
| * write to a single underlying stream, which is |
| * closed only when the last "funnel" |
| * has been closed. |
| */ |
| public class OutputStreamFunneler { |
| |
| /** |
| * Default timeout. |
| * @see #setTimeout(long) |
| */ |
| public static final long DEFAULT_TIMEOUT_MILLIS = 1000; |
| |
| private final class Funnel extends OutputStream { |
| private boolean closed = false; |
| |
| private Funnel() { |
| synchronized (OutputStreamFunneler.this) { |
| ++count; |
| } |
| } |
| |
| public void flush() throws IOException { |
| synchronized (OutputStreamFunneler.this) { |
| dieIfClosed(); |
| out.flush(); |
| } |
| } |
| |
| public void write(int b) throws IOException { |
| synchronized (OutputStreamFunneler.this) { |
| dieIfClosed(); |
| out.write(b); |
| } |
| } |
| |
| public void write(byte[] b) throws IOException { |
| synchronized (OutputStreamFunneler.this) { |
| dieIfClosed(); |
| out.write(b); |
| } |
| } |
| |
| public void write(byte[] b, int off, int len) throws IOException { |
| synchronized (OutputStreamFunneler.this) { |
| dieIfClosed(); |
| out.write(b, off, len); |
| } |
| } |
| |
| public void close() throws IOException { |
| release(this); |
| } |
| } |
| |
| private OutputStream out; |
| private int count = 0; |
| private boolean closed; |
| private long timeoutMillis; |
| |
| /** |
| * Create a new <code>OutputStreamFunneler</code> for |
| * the specified <code>OutputStream</code>. |
| * @param out <code>OutputStream</code>. |
| */ |
| public OutputStreamFunneler(OutputStream out) { |
| this(out, DEFAULT_TIMEOUT_MILLIS); |
| } |
| |
| /** |
| * Create a new <code>OutputStreamFunneler</code> for |
| * the specified <code>OutputStream</code>, with the |
| * specified timeout value. |
| * @param out <code>OutputStream</code>. |
| * @param timeoutMillis <code>long</code>. |
| * @see #setTimeout(long) |
| */ |
| public OutputStreamFunneler(OutputStream out, long timeoutMillis) { |
| if (out == null) { |
| throw new IllegalArgumentException( |
| "OutputStreamFunneler.<init>: out == null"); |
| } |
| this.out = out; |
| this.closed = false; //as far as we know |
| setTimeout(timeoutMillis); |
| } |
| |
| /** |
| * Set the timeout for this <code>OutputStreamFunneler</code>. |
| * This is the maximum time that may elapse between the closure |
| * of the last "funnel" and the next call to |
| * <code>getOutputStream()</code> without closing the |
| * underlying stream. |
| * @param timeoutMillis <code>long</code> timeout value. |
| */ |
| public synchronized void setTimeout(long timeoutMillis) { |
| this.timeoutMillis = timeoutMillis; |
| } |
| |
| /** |
| * Get a "funnel" <code>OutputStream</code> instance to |
| * write to this <code>OutputStreamFunneler</code>'s underlying |
| * <code>OutputStream</code>. |
| * @return <code>OutputStream</code>. |
| * @throws IOException if unable to create the funnel. |
| */ |
| public synchronized OutputStream getFunnelInstance() |
| throws IOException { |
| dieIfClosed(); |
| try { |
| return new Funnel(); |
| } finally { |
| notifyAll(); |
| } |
| } |
| |
| private synchronized void release(Funnel funnel) throws IOException { |
| //ignore release of an already-closed funnel |
| if (!funnel.closed) { |
| try { |
| if (timeoutMillis > 0) { |
| try { |
| wait(timeoutMillis); |
| } catch (InterruptedException eyeEx) { |
| //ignore |
| } |
| } |
| if (--count == 0) { |
| close(); |
| } |
| } finally { |
| funnel.closed = true; |
| } |
| } |
| } |
| |
| private synchronized void close() throws IOException { |
| try { |
| dieIfClosed(); |
| out.close(); |
| } finally { |
| closed = true; |
| } |
| } |
| |
| private synchronized void dieIfClosed() throws IOException { |
| if (closed) { |
| throw new IOException("The funneled OutputStream has been closed."); |
| } |
| } |
| |
| } |