/*
 * 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.commons.vfs2.util;

import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.commons.vfs2.FileSystemException;

An OutputStream that provides buffering and end-of-stream monitoring.
/** * An OutputStream that provides buffering and end-of-stream monitoring. */
public class MonitorOutputStream extends BufferedOutputStream { private final AtomicBoolean finished = new AtomicBoolean(false);
Constructs a MonitorOutputStream from the passed OutputStream
Params:
  • out – The output stream to wrap.
/** * Constructs a MonitorOutputStream from the passed OutputStream * * @param out The output stream to wrap. */
public MonitorOutputStream(final OutputStream out) { super(out); }
Constructs a MonitorOutputStream from the passed OutputStream and with the specified buffer size
Params:
  • out – The output stream to wrap.
  • bufferSize – The buffer size to use.
Since:2.4
/** * Constructs a MonitorOutputStream from the passed OutputStream and with the specified buffer size * * @param out The output stream to wrap. * @param bufferSize The buffer size to use. * @since 2.4 */
public MonitorOutputStream(final OutputStream out, final int bufferSize) { super(out, bufferSize); }
Closes this output stream.

This makes sure the buffers are flushed, close the output stream and it will call onClose() and re-throw last exception from any of the three.

This does nothing if the stream is closed already.

Throws:
/** * Closes this output stream. * <p> * This makes sure the buffers are flushed, close the output stream and it will call {@link #onClose()} and re-throw * last exception from any of the three. * </p> * <p> * This does nothing if the stream is closed already. * </p> * * @throws IOException if an error occurs. */
@Override public void close() throws IOException { // do not use super.close() // on Java 8 it might throw self suppression, see JDK-8042377 // in older Java it silently ignores flush() errors if (finished.getAndSet(true)) { return; } IOException exc = null; // flush the buffer and out stream try { super.flush(); } catch (final IOException ioe) { exc = ioe; } // close the out stream without using super.close() try { super.out.close(); } catch (final IOException ioe) { exc = ioe; } // Notify of end of output try { onClose(); } catch (final IOException ioe) { exc = ioe; } if (exc != null) { throw exc; } }
Params:
  • b – The character to write.
Throws:
Since:2.0
/** * @param b The character to write. * @throws IOException if an error occurs. * @since 2.0 */
@Override public synchronized void write(final int b) throws IOException { assertOpen(); super.write(b); }
Params:
  • b – The byte array.
  • off – The offset into the array.
  • len – The number of bytes to write.
Throws:
Since:2.0
/** * @param b The byte array. * @param off The offset into the array. * @param len The number of bytes to write. * @throws IOException if an error occurs. * @since 2.0 */
@Override public synchronized void write(final byte[] b, final int off, final int len) throws IOException { assertOpen(); super.write(b, off, len); }
Throws:
  • IOException – if an error occurs.
Since:2.0
/** * @throws IOException if an error occurs. * @since 2.0 */
@Override public synchronized void flush() throws IOException { assertOpen(); super.flush(); }
Params:
  • b – The byte array.
Throws:
Since:2.0
/** * @param b The byte array. * @throws IOException if an error occurs. * @since 2.0 */
@Override public void write(final byte[] b) throws IOException { assertOpen(); super.write(b); }
Check if file is still open.

This is a workaround for an oddity with Java's BufferedOutputStream where you can write to even if the stream has been closed.

Throws:
  • FileSystemException – if already closed.
Since:2.0
/** * Check if file is still open. * <p> * This is a workaround for an oddity with Java's BufferedOutputStream where you can write to even if the stream has * been closed. * </p> * * @throws FileSystemException if already closed. * @since 2.0 */
protected void assertOpen() throws FileSystemException { if (finished.get()) { throw new FileSystemException("vfs.provider/closed.error"); } }
Called after this stream is closed.

This implementation does nothing.

Throws:
  • IOException – if an error occurs.
/** * Called after this stream is closed. * <p> * This implementation does nothing. * </p> * * @throws IOException if an error occurs. */
// IOException is needed because subclasses may need to throw it protected void onClose() throws IOException { } }