IOUtils.java

package org.softeg.slartus.forpdaplus.classes.common;

/**
 * User: slinkin
 * Date: 30.08.11
 * Time: 16:21
 */

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class IOUtils {

	private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

	// copy from InputStream
	// -----------------------------------------------------------------------
	/**
	 * Copy bytes from an <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 * <p>
	 * Large streams (over 2GB) will return a bytes copied value of
	 * <code>-1</code> after the copy has completed since the correct number of
	 * bytes cannot be returned as an int. For large streams use the
	 * <code>copyLarge(InputStream, OutputStream)</code> method.
	 *
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied, or -1 if > Integer.MAX_VALUE
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.1
	 */
	public static int copy(InputStream input, OutputStream output)
			throws IOException {
		long count = copyLarge(input, output);
		if (count > Integer.MAX_VALUE) {
			return -1;
		}
		return (int) count;
	}

	/**
	 * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
	 * <code>OutputStream</code>.
	 * <p>
	 * This method buffers the input internally, so there is no need to use a
	 * <code>BufferedInputStream</code>.
	 *
	 * @param input
	 *            the <code>InputStream</code> to read from
	 * @param output
	 *            the <code>OutputStream</code> to write to
	 * @return the number of bytes copied
	 * @throws NullPointerException
	 *             if the input or output is null
	 * @throws IOException
	 *             if an I/O error occurs
	 * @since Commons IO 1.3
	 */
	public static long copyLarge(InputStream input, OutputStream output)
			throws IOException {
		byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
		long count = 0;
		int n = 0;
		while (-1 != (n = input.read(buffer))) {
			output.write(buffer, 0, n);
			count += n;
		}
		return count;
	}
}