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EasyStream is a small set of utilities for dealing with streams (InputStreams and OutputStreams). The aim is to ease the use of pipes when they're required. Main features are: * "Convert" an OutputStream to an InputStream. * Count the number of bytes read or wrote to a given stream. * While reading the data from an InputStream copy it to a supplied OutputStream. * Read the content of an InputStream multiple times or seek to a definite position

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package com.gc.iotools.stream.os;

/*
 * Copyright (c) 2008, 2015 Gabriele Contini. This source code is released
 * under the BSD License.
 */
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * 
 * A decorating OutputStream that prevents multiple invocations of
 * the {@linkplain #close()} method on the underlying stream.
 * 
 * 
 * Multiple invocation of the close() method will result in only
 * one invocation of the same method on the underlying stream. This is useful
 * with some non standard OutputStream that don't allow
 * close() to be called multiple times.
 * 
 * 
 * @author Gabriele Contini
 * @since 1.2.14
 * @param 
 *            Type of the OutputStream passed in the constructor.
 * @version $Id: CloseOnceOutputStream.java 523 2013-01-02 15:46:17Z
 *           $
 */
public class CloseOnceOutputStream extends
		FilterOutputStream {
	private int closeCount = 0;

	/**
	 * Construct a CloseOnceOutputStream that forwards the calls to
	 * the source OutputStream passed in the constructor.
	 * 
	 * @param source
	 *            original OutputStream
	 */
	public CloseOnceOutputStream(final T source) {
		super(source);
	}

	/**
	 * {@inheritDoc}
	 * 
	 * 
	 * Multiple invocation of this method will result in only one invocation of
	 * the close() on the underlying stream.
	 * 
	 */
	@Override
	public void close() throws IOException {
		synchronized (this) {
			this.closeCount++;
			if (this.closeCount > 1) {
				return;
			}
		}
		super.close();
	}

	/**
	 * Returns the number of time that close was called.
	 * 
	 * @see com.gc.iotools.stream.is.inspection.DiagnosticOutputStream
	 * @return Number of times that close was called
	 */
	public int getCloseCount() {
		return this.closeCount;
	}

	/**
	 * 
	 * Returns the wrapped (original) OutputStream passed in the
	 * constructor.
	 * 
	 * 
	 * @return The original OutputStream passed in the constructor
	 */
	public T getWrappedOutputStream() {
		@SuppressWarnings("unchecked")
		final T result = (T) super.out;
		return result;
	}
}