/**
 * Copyright (C) 2016 LibRec
 * <p>
 * This file is part of LibRec.
 * LibRec is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * <p>
 * LibRec is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with LibRec. If not, see <http://www.gnu.org/licenses/>.
 */
package net.librec.util;

import java.io.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * IOUtil
 */
public class IOUtil {
    // 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;

    //-----------------------------------------------------------------------

    /**
     * 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) {
            // 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) {
            // 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) {
            // 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) {
            // 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 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 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 readLines(Reader input) throws IOException {
        BufferedReader reader = new BufferedReader(input);
        List list = new ArrayList();
        String line = reader.readLine();
        while (line != null) {
            list.add(line);
            line = reader.readLine();
        }
        return list;
    }

    //-----------------------------------------------------------------------

    /**
     * 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
     * @return an input stream
     * @throws IOException if the encoding is invalid
     * @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 lines, String lineEnding,
                                  OutputStream output) throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (Iterator it = lines.iterator(); it.hasNext(); ) {
            Object line = it.next();
            if (line != null) {
                output.write(line.toString().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 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 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 lines, String lineEnding,
                                  Writer writer) throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (Iterator it = lines.iterator(); it.hasNext(); ) {
            Object line = it.next();
            if (line != null) {
                writer.write(line.toString());
            }
            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);
    }


}
