fr.opensagres.odfdom.converter.core.utils.IOUtils.java Source code

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/**
 * Copyright (C) 2011-2015 The XDocReport Team <xdocreport@googlegroups.com>
 *
 * All rights reserved.
 *
 * Permission is hereby granted, free  of charge, to any person obtaining
 * a  copy  of this  software  and  associated  documentation files  (the
 * "Software"), to  deal in  the Software without  restriction, including
 * without limitation  the rights to  use, copy, modify,  merge, publish,
 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
 * permit persons to whom the Software  is furnished to do so, subject to
 * the following conditions:
 *
 * The  above  copyright  notice  and  this permission  notice  shall  be
 * included in all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
package fr.opensagres.odfdom.converter.core.utils;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayWriter;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

//import org.apache.commons.io.output.ByteArrayOutputStream;

/**
 * General IO stream manipulation utilities.
 * <p>
 * This class provides static utility methods for input/output operations.
 * <ul>
 * <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
 * <li>toXxx/read - these methods read data from a stream
 * <li>write - these methods write data to a stream
 * <li>copy - these methods copy all the data from one stream to another
 * <li>contentEquals - these methods compare the content of two streams
 * </ul>
 * <p>
 * The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case,
 * one that uses the platform default encoding and the other which allows you to specify an encoding. You are encouraged
 * to always specify an encoding because relying on the platform default can lead to unexpected results, for example
 * when moving from development to production.
 * <p>
 * All the methods in this class that read a stream are buffered internally. This means that there is no cause to use a
 * <code>BufferedInputStream</code> or <code>BufferedReader</code>. The default buffer size of 4K has been shown to be
 * efficient in tests.
 * <p>
 * Wherever possible, the methods in this class do <em>not</em> flush or close the stream. This is to avoid making
 * non-portable assumptions about the streams' origin and further use. Thus the caller is still responsible for closing
 * streams after use.
 * <p>
 * Origin of code: Excalibur.
 * 
 * @author Peter Donald
 * @author Jeff Turner
 * @author Matthew Hawthorne
 * @author Stephen Colebourne
 * @author Gareth Davis
 * @author Ian Springer
 * @author Niall Pemberton
 * @author Sandy McArthur
 * @version $Id: IOUtils.java 481854 2006-12-03 18:30:07Z scolebourne $
 */
public class IOUtils {
    /**
     * Logger for this class
     */
    //private static final Logger logger = LogUtils.getLogger( IOUtils.class.getName() );

    // NOTE: This class is focussed on InputStream, OutputStream, Reader and
    // Writer. Each method should take at least one of these as a parameter,
    // or return one of them.

    /**
     * The Unix directory separator character.
     */
    public static final char DIR_SEPARATOR_UNIX = '/';

    /**
     * The Windows directory separator character.
     */
    public static final char DIR_SEPARATOR_WINDOWS = '\\';

    /**
     * The system directory separator character.
     */
    public static final char DIR_SEPARATOR = File.separatorChar;

    /**
     * The Unix line separator string.
     */
    public static final String LINE_SEPARATOR_UNIX = "\n";

    /**
     * The Windows line separator string.
     */
    public static final String LINE_SEPARATOR_WINDOWS = "\r\n";

    /**
     * The system line separator string.
     */
    public static final String LINE_SEPARATOR;
    static {
        // avoid security issues
        StringWriter buf = new StringWriter(4);
        PrintWriter out = new PrintWriter(buf);
        out.println();
        LINE_SEPARATOR = buf.toString();
    }

    /**
     * The default buffer size to use.
     */
    private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

    /**
     * Instances should NOT be constructed in standard programming.
     */
    public IOUtils() {
        super();
    }

    // -----------------------------------------------------------------------
    /**
     * Unconditionally close an <code>Reader</code>.
     * <p>
     * Equivalent to {@link Reader#close()}, except any exceptions will be ignored. This is typically used in finally
     * blocks.
     * 
     * @param input the Reader to close, may be null or already closed
     */
    public static void closeQuietly(Reader input) {
        try {
            if (input != null) {
                input.close();
            }
        } catch (IOException ioe) {
            //logger.warning( "Reader - exception ignored - exception: " + ioe ); //$NON-NLS-1$

            // ignore
        }
    }

    /**
     * Unconditionally close a <code>Writer</code>.
     * <p>
     * Equivalent to {@link Writer#close()}, except any exceptions will be ignored. This is typically used in finally
     * blocks.
     * 
     * @param output the Writer to close, may be null or already closed
     */
    public static void closeQuietly(Writer output) {
        try {
            if (output != null) {
                output.close();
            }
        } catch (IOException ioe) {
            //logger.warning( "Writer - exception ignored - exception: " + ioe ); //$NON-NLS-1$

            // ignore
        }
    }

    /**
     * Unconditionally close an <code>InputStream</code>.
     * <p>
     * Equivalent to {@link InputStream#close()}, except any exceptions will be ignored. This is typically used in
     * finally blocks.
     * 
     * @param input the InputStream to close, may be null or already closed
     */
    public static void closeQuietly(InputStream input) {
        try {
            if (input != null) {
                input.close();
            }
        } catch (IOException ioe) {
            //logger.warning( "InputStream - exception ignored - exception: " + ioe ); //$NON-NLS-1$

            // ignore
        }
    }

    /**
     * Unconditionally close an <code>OutputStream</code>.
     * <p>
     * Equivalent to {@link OutputStream#close()}, except any exceptions will be ignored. This is typically used in
     * finally blocks.
     * 
     * @param output the OutputStream to close, may be null or already closed
     */
    public static void closeQuietly(OutputStream output) {
        try {
            if (output != null) {
                output.close();
            }
        } catch (IOException ioe) {
            //logger.warning( "OutputStream - exception ignored - exception: " + ioe ); //$NON-NLS-1$

            // ignore
        }
    }

    // read toByteArray
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a <code>byte[]</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
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     */
    public static byte[] toByteArray(InputStream input) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output);
        return output.toByteArray();
    }

    /**
     * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using the default character encoding of the
     * platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     */
    public static byte[] toByteArray(Reader input) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output);
        return output.toByteArray();
    }

    /**
     * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static byte[] toByteArray(Reader input, String encoding) throws IOException {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output, encoding);
        return output.toByteArray();
    }

    /**
     * Get the contents of a <code>String</code> as a <code>byte[]</code> using the default character encoding of the
     * platform.
     * <p>
     * This is the same as {@link String#getBytes()}.
     * 
     * @param input the <code>String</code> to convert
     * @return the requested byte array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs (never occurs)
     * @deprecated Use {@link String#getBytes()}
     */
    public static byte[] toByteArray(String input) throws IOException {
        return input.getBytes();
    }

    // read char[]
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a character array using the default character encoding of the
     * platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedInputStream</code>.
     * 
     * @param is the <code>InputStream</code> to read from
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static char[] toCharArray(InputStream is) throws IOException {
        CharArrayWriter output = new CharArrayWriter();
        copy(is, output);
        return output.toCharArray();
    }

    /**
     * Get the contents of an <code>InputStream</code> as a character array using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedInputStream</code>.
     * 
     * @param is the <code>InputStream</code> to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static char[] toCharArray(InputStream is, String encoding) throws IOException {
        CharArrayWriter output = new CharArrayWriter();
        copy(is, output, encoding);
        return output.toCharArray();
    }

    /**
     * Get the contents of a <code>Reader</code> as a character array.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from
     * @return the requested character array
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static char[] toCharArray(Reader input) throws IOException {
        CharArrayWriter sw = new CharArrayWriter();
        copy(input, sw);
        return sw.toCharArray();
    }

    // read toString
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a String using the default character encoding of the platform.
     * <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
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     */
    public static String toString(InputStream input) throws IOException {
        StringWriter sw = new StringWriter();
        copy(input, sw);
        return sw.toString();
    }

    /**
     * Get the contents of an <code>InputStream</code> as a String using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <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 encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     */
    public static String toString(InputStream input, String encoding) throws IOException {
        StringWriter sw = new StringWriter();
        copy(input, sw, encoding);
        return sw.toString();
    }

    /**
     * Get the contents of a <code>Reader</code> as a String.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     */
    public static String toString(Reader input) throws IOException {
        StringWriter sw = new StringWriter();
        copy(input, sw);
        return sw.toString();
    }

    /**
     * Get the contents of a <code>byte[]</code> as a String using the default character encoding of the platform.
     * 
     * @param input the byte array to read from
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs (never occurs)
     * @deprecated Use {@link String#String(byte[])}
     */
    public static String toString(byte[] input) throws IOException {
        return new String(input);
    }

    /**
     * Get the contents of a <code>byte[]</code> as a String using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * 
     * @param input the byte array to read from
     * @param encoding the encoding to use, null means platform default
     * @return the requested String
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs (never occurs)
     * @deprecated Use {@link String#String(byte[],String)}
     */
    public static String toString(byte[] input, String encoding) throws IOException {
        if (encoding == null) {
            return new String(input);
        } else {
            return new String(input, encoding);
        }
    }

    // readLines
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a list of Strings, one entry per line, using the default
     * character encoding of the platform.
     * <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, not null
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static List<String> readLines(InputStream input) throws IOException {
        InputStreamReader reader = new InputStreamReader(input);
        return readLines(reader);
    }

    /**
     * Get the contents of an <code>InputStream</code> as a list of Strings, one entry per line, using the specified
     * character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <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, not null
     * @param encoding the encoding to use, null means platform default
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static List<String> readLines(InputStream input, String encoding) throws IOException {
        if (encoding == null) {
            return readLines(input);
        } else {
            InputStreamReader reader = new InputStreamReader(input, encoding);
            return readLines(reader);
        }
    }

    /**
     * Get the contents of a <code>Reader</code> as a list of Strings, one entry per line.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from, not null
     * @return the list of Strings, never null
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static List<String> readLines(Reader input) throws IOException {
        BufferedReader reader = new BufferedReader(input);
        List<String> list = new ArrayList<String>();
        String line = reader.readLine();
        while (line != null) {
            list.add(line);
            line = reader.readLine();
        }
        return list;
    }

    // lineIterator
    // -----------------------------------------------------------------------
    /**
     * Return an Iterator for the lines in a <code>Reader</code>.
     * <p>
     * <code>LineIterator</code> holds a reference to the open <code>Reader</code> specified here. When you have
     * finished with the iterator you should close the reader to free internal resources. This can be done by closing
     * the reader directly, or by calling {@link LineIterator#close()} or
     * {@link LineIterator#closeQuietly(LineIterator)}.
     * <p>
     * The recommended usage pattern is:
     * 
     * <pre>
     * try
     * {
     *     LineIterator it = IOUtils.lineIterator( reader );
     *     while ( it.hasNext() )
     *     {
     *         String line = it.nextLine();
     *         // / do something with line
     *     }
     * }
     * finally
     * {
     *     IOUtils.closeQuietly( reader );
     * }
     * </pre>
     * 
     * @param reader the <code>Reader</code> to read from, not null
     * @return an Iterator of the lines in the reader, never null
     * @throws IllegalArgumentException if the reader is null
     * @since Commons IO 1.2
    //     */
    //    public static LineIterator lineIterator( Reader reader )
    //    {
    //        return new LineIterator( reader );
    //    }

    /**
     * Return an Iterator for the lines in an <code>InputStream</code>, using the character encoding specified (or
     * default encoding if null).
     * <p>
     * <code>LineIterator</code> holds a reference to the open <code>InputStream</code> specified here. When you have
     * finished with the iterator you should close the stream to free internal resources. This can be done by closing
     * the stream directly, or by calling {@link LineIterator#close()} or
     * {@link LineIterator#closeQuietly(LineIterator)}.
     * <p>
     * The recommended usage pattern is:
     * 
     * <pre>
     * try
     * {
     *     LineIterator it = IOUtils.lineIterator( stream, &quot;UTF-8&quot; );
     *     while ( it.hasNext() )
     *     {
     *         String line = it.nextLine();
     *         // / do something with line
     *     }
     * }
     * finally
     * {
     *     IOUtils.closeQuietly( stream );
     * }
     * </pre>
     * 
     * @param input the <code>InputStream</code> to read from, not null
     * @param encoding the encoding to use, null means platform default
     * @return an Iterator of the lines in the reader, never null
     * @throws IllegalArgumentException if the input is null
     * @throws IOException if an I/O error occurs, such as if the encoding is invalid
     * @since Commons IO 1.2
     */
    //    public static LineIterator lineIterator( InputStream input, String encoding )
    //        throws IOException
    //    {
    //        Reader reader = null;
    //        if ( encoding == null )
    //        {
    //            reader = new InputStreamReader( input );
    //        }
    //        else
    //        {
    //            reader = new InputStreamReader( input, encoding );
    //        }
    //        return new LineIterator( reader );
    //    }

    // -----------------------------------------------------------------------
    /**
     * Convert the specified string to an input stream, encoded as bytes using the default character encoding of the
     * platform.
     * 
     * @param input the string to convert
     * @return an input stream
     * @since Commons IO 1.1
     */
    public static InputStream toInputStream(String input) {
        byte[] bytes = input.getBytes();
        return new ByteArrayInputStream(bytes);
    }

    /**
     * Convert the specified string to an input stream, encoded as bytes using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * 
     * @param input the string to convert
     * @param encoding the encoding to use, null means platform default
     * @throws IOException if the encoding is invalid
     * @return an input stream
     * @since Commons IO 1.1
     */
    public static InputStream toInputStream(String input, String encoding) throws IOException {
        byte[] bytes = encoding != null ? input.getBytes(encoding) : input.getBytes();
        return new ByteArrayInputStream(bytes);
    }

    // write byte[]
    // -----------------------------------------------------------------------
    /**
     * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
     * 
     * @param data the byte array to write, do not modify during output, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(byte[] data, OutputStream output) throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    /**
     * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code> using the default character encoding of
     * the platform.
     * <p>
     * This method uses {@link String#String(byte[])}.
     * 
     * @param data the byte array to write, do not modify during output, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(byte[] data, Writer output) throws IOException {
        if (data != null) {
            output.write(new String(data));
        }
    }

    /**
     * Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#String(byte[], String)}.
     * 
     * @param data the byte array to write, do not modify during output, null ignored
     * @param output the <code>Writer</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(byte[] data, Writer output, String encoding) throws IOException {
        if (data != null) {
            if (encoding == null) {
                write(data, output);
            } else {
                output.write(new String(data, encoding));
            }
        }
    }

    // write char[]
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>char[]</code> to a <code>Writer</code> using the default character encoding of the
     * platform.
     * 
     * @param data the char array to write, do not modify during output, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(char[] data, Writer output) throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    /**
     * Writes chars from a <code>char[]</code> to bytes on an <code>OutputStream</code>.
     * <p>
     * This method uses {@link String#String(char[])} and {@link String#getBytes()}.
     * 
     * @param data the char array to write, do not modify during output, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(char[] data, OutputStream output) throws IOException {
        if (data != null) {
            output.write(new String(data).getBytes());
        }
    }

    /**
     * Writes chars from a <code>char[]</code> to bytes on an <code>OutputStream</code> using the specified character
     * encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#String(char[])} and {@link String#getBytes(String)}.
     * 
     * @param data the char array to write, do not modify during output, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(char[] data, OutputStream output, String encoding) throws IOException {
        if (data != null) {
            if (encoding == null) {
                write(data, output);
            } else {
                output.write(new String(data).getBytes(encoding));
            }
        }
    }

    // write String
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>String</code> to a <code>Writer</code>.
     * 
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(String data, Writer output) throws IOException {
        if (data != null) {
            output.write(data);
        }
    }

    /**
     * Writes chars from a <code>String</code> to bytes on an <code>OutputStream</code> using the default character
     * encoding of the platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     * 
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(String data, OutputStream output) throws IOException {
        if (data != null) {
            output.write(data.getBytes());
        }
    }

    /**
     * Writes chars from a <code>String</code> to bytes on an <code>OutputStream</code> using the specified character
     * encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     * 
     * @param data the <code>String</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(String data, OutputStream output, String encoding) throws IOException {
        if (data != null) {
            if (encoding == null) {
                write(data, output);
            } else {
                output.write(data.getBytes(encoding));
            }
        }
    }

    // write StringBuffer
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
     * 
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(StringBuffer data, Writer output) throws IOException {
        if (data != null) {
            output.write(data.toString());
        }
    }

    /**
     * Writes chars from a <code>StringBuffer</code> to bytes on an <code>OutputStream</code> using the default
     * character encoding of the platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     * 
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(StringBuffer data, OutputStream output) throws IOException {
        if (data != null) {
            output.write(data.toString().getBytes());
        }
    }

    /**
     * Writes chars from a <code>StringBuffer</code> to bytes on an <code>OutputStream</code> using the specified
     * character encoding.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     * 
     * @param data the <code>StringBuffer</code> to write, null ignored
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void write(StringBuffer data, OutputStream output, String encoding) throws IOException {
        if (data != null) {
            if (encoding == null) {
                write(data, output);
            } else {
                output.write(data.toString().getBytes(encoding));
            }
        }
    }

    // writeLines
    // -----------------------------------------------------------------------
    /**
     * Writes the <code>toString()</code> value of each item in a collection to an <code>OutputStream</code> line by
     * line, using the default character encoding of the platform and the specified line ending.
     * 
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param output the <code>OutputStream</code> to write to, not null, not closed
     * @throws NullPointerException if the output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void writeLines(Collection<String> lines, String lineEnding, OutputStream output)
            throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (Iterator<String> it = lines.iterator(); it.hasNext();) {
            String line = it.next();
            if (line != null) {
                output.write(line.getBytes());
            }
            output.write(lineEnding.getBytes());
        }
    }

    /**
     * Writes the <code>toString()</code> value of each item in a collection to an <code>OutputStream</code> line by
     * line, using the specified character encoding and the specified line ending.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * 
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param output the <code>OutputStream</code> to write to, not null, not closed
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if the output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void writeLines(Collection<String> lines, String lineEnding, OutputStream output, String encoding)
            throws IOException {
        if (encoding == null) {
            writeLines(lines, lineEnding, output);
        } else {
            if (lines == null) {
                return;
            }
            if (lineEnding == null) {
                lineEnding = LINE_SEPARATOR;
            }
            for (Iterator<String> it = lines.iterator(); it.hasNext();) {
                Object line = it.next();
                if (line != null) {
                    output.write(line.toString().getBytes(encoding));
                }
                output.write(lineEnding.getBytes(encoding));
            }
        }
    }

    /**
     * Writes the <code>toString()</code> value of each item in a collection to a <code>Writer</code> line by line,
     * using the specified line ending.
     * 
     * @param lines the lines to write, null entries produce blank lines
     * @param lineEnding the line separator to use, null is system default
     * @param writer the <code>Writer</code> to write to, not null, not closed
     * @throws NullPointerException if the input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void writeLines(Collection<String> lines, String lineEnding, Writer writer) throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (Iterator<String> it = lines.iterator(); it.hasNext();) {
            String line = it.next();
            if (line != null) {
                writer.write(line);
            }
            writer.write(lineEnding);
        }
    }

    // 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
     * @throws NullPointerException if the input or output is null
     * @throws IOException if an I/O error occurs
     * @throws ArithmeticException if the byte count is too large
     * @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;
    }

    /**
     * Copy bytes from an <code>InputStream</code> to chars on a <code>Writer</code> using the default character
     * encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedInputStream</code>.
     * <p>
     * This method uses {@link InputStreamReader}.
     * 
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>Writer</code> to write to
     * @throws NullPointerException if the input or output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void copy(InputStream input, Writer output) throws IOException {
        InputStreamReader in = new InputStreamReader(input);
        copy(in, output);
    }

    /**
     * Copy bytes from an <code>InputStream</code> to chars on a <code>Writer</code> using the specified character
     * encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedInputStream</code>.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link InputStreamReader}.
     * 
     * @param input the <code>InputStream</code> to read from
     * @param output the <code>Writer</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if the input or output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void copy(InputStream input, Writer output, String encoding) throws IOException {
        if (encoding == null) {
            copy(input, output);
        } else {
            InputStreamReader in = new InputStreamReader(input, encoding);
            copy(in, output);
        }
    }

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

    /**
     * Copy chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * 
     * @param input the <code>Reader</code> to read from
     * @param output the <code>Writer</code> to write to
     * @return the number of characters 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(Reader input, Writer output) throws IOException {
        char[] buffer = new char[DEFAULT_BUFFER_SIZE];
        long count = 0;
        int n = 0;
        while (-1 != (n = input.read(buffer))) {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    /**
     * Copy chars from a <code>Reader</code> to bytes on an <code>OutputStream</code> using the default character
     * encoding of the platform, and calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * 
     * @param input the <code>Reader</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @throws NullPointerException if the input or output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void copy(Reader input, OutputStream output) throws IOException {
        OutputStreamWriter out = new OutputStreamWriter(output);
        copy(input, out);
        // XXX Unless anyone is planning on rewriting OutputStreamWriter, we
        // have to flush here.
        out.flush();
    }

    /**
     * Copy chars from a <code>Reader</code> to bytes on an <code>OutputStream</code> using the specified character
     * encoding, and calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a <code>BufferedReader</code>.
     * <p>
     * Character encoding names can be found at <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * 
     * @param input the <code>Reader</code> to read from
     * @param output the <code>OutputStream</code> to write to
     * @param encoding the encoding to use, null means platform default
     * @throws NullPointerException if the input or output is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static void copy(Reader input, OutputStream output, String encoding) throws IOException {
        if (encoding == null) {
            copy(input, output);
        } else {
            OutputStreamWriter out = new OutputStreamWriter(output, encoding);
            copy(input, out);
            // XXX Unless anyone is planning on rewriting OutputStreamWriter,
            // we have to flush here.
            out.flush();
        }
    }

    // content equals
    // -----------------------------------------------------------------------
    /**
     * Compare the contents of two Streams to determine if they are equal or not.
     * <p>
     * This method buffers the input internally using <code>BufferedInputStream</code> if they are not already buffered.
     * 
     * @param input1 the first stream
     * @param input2 the second stream
     * @return true if the content of the streams are equal or they both don't exist, false otherwise
     * @throws NullPointerException if either input is null
     * @throws IOException if an I/O error occurs
     */
    public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException {
        if (!(input1 instanceof BufferedInputStream)) {
            input1 = new BufferedInputStream(input1);
        }
        if (!(input2 instanceof BufferedInputStream)) {
            input2 = new BufferedInputStream(input2);
        }

        int ch = input1.read();
        while (-1 != ch) {
            int ch2 = input2.read();
            if (ch != ch2) {
                return false;
            }
            ch = input1.read();
        }

        int ch2 = input2.read();
        return (ch2 == -1);
    }

    /**
     * Compare the contents of two Readers to determine if they are equal or not.
     * <p>
     * This method buffers the input internally using <code>BufferedReader</code> if they are not already buffered.
     * 
     * @param input1 the first reader
     * @param input2 the second reader
     * @return true if the content of the readers are equal or they both don't exist, false otherwise
     * @throws NullPointerException if either input is null
     * @throws IOException if an I/O error occurs
     * @since Commons IO 1.1
     */
    public static boolean contentEquals(Reader input1, Reader input2) throws IOException {
        if (!(input1 instanceof BufferedReader)) {
            input1 = new BufferedReader(input1);
        }
        if (!(input2 instanceof BufferedReader)) {
            input2 = new BufferedReader(input2);
        }

        int ch = input1.read();
        while (-1 != ch) {
            int ch2 = input2.read();
            if (ch != ch2) {
                return false;
            }
            ch = input1.read();
        }

        int ch2 = input2.read();
        return (ch2 == -1);
    }

}