com.aoyetech.fee.commons.utils.IOUtils.java Source code

Java tutorial

Introduction

Here is the source code for com.aoyetech.fee.commons.utils.IOUtils.java

Source

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.aoyetech.fee.commons.utils;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.CharArrayWriter;
import java.io.Closeable;
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.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * modify from common-io
 * 
 * @author Peter Donald
 * @author Jeff Turner
 * @author Matthew Hawthorne
 * @author Stephen Colebourne
 * @author Gareth Davis
 * @author Ian Springer
 * @author Niall Pemberton
 * @author Sandy McArthur
 * @author <a href=mailto://wq163@163.com>jenwang</a>
 * @since 2012-12-5 ?11:54:39
 * @see org.apache.commons.io.IOUtils
 **/
public class IOUtils {
    // 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
        final StringWriter buf = new StringWriter(4);
        final 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();
    }

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

    public static void closeQuietly(final Closeable closeable) {
        try {
            if (closeable != null) {
                closeable.close();
            }
        } catch (final 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(final InputStream input) throws IOException {
        final 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(final Reader input) throws IOException {
        final 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(final Reader input, final String encoding) throws IOException {
        final 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()}
     */
    @Deprecated
    public static byte[] toByteArray(final 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(final InputStream is) throws IOException {
        final 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(final InputStream is, final String encoding) throws IOException {
        final 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(final Reader input) throws IOException {
        final 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(final InputStream input) throws IOException {
        final 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(final InputStream input, final String encoding) throws IOException {
        final 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(final Reader input) throws IOException {
        final StringWriter sw = new StringWriter();
        copy(input, sw);
        return sw.toString();
    }

    // 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(final InputStream input) throws IOException {
        final 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(final InputStream input, final String encoding) throws IOException {
        if (encoding == null) {
            return readLines(input);
        } else {
            final 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(final Reader input) throws IOException {
        final BufferedReader reader = new BufferedReader(input);
        final List<String> list = new ArrayList<String>();
        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(final String input) {
        final 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(final String input, final String encoding) throws IOException {
        final 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(final byte[] data, final 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(final byte[] data, final 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(final byte[] data, final Writer output, final 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(final char[] data, final 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(final char[] data, final 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(final char[] data, final OutputStream output, final 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(final String data, final 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(final String data, final 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(final String data, final OutputStream output, final 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(final StringBuffer data, final 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(final StringBuffer data, final 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(final StringBuffer data, final OutputStream output, final String encoding)
            throws IOException {
        if (data != null) {
            if (encoding == null) {
                write(data, output);
            } else {
                output.write(data.toString().getBytes(encoding));
            }
        }
    }

    public static void write(final String data, final OutputStream output, final Charset encoding)
            throws IOException {
        if (data != null) {
            output.write(data.getBytes(toCharset(encoding)));
        }
    }

    public static Charset toCharset(final Charset charset) {
        return charset == null ? Charset.defaultCharset() : charset;
    }

    public static Charset toCharset(final String charset) {
        return charset == null ? Charset.defaultCharset() : Charset.forName(charset);
    }

    // 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(final Collection<?> lines, String lineEnding, final OutputStream output)
            throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (final Iterator<?> it = lines.iterator(); it.hasNext();) {
            final 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(final Collection<?> lines, String lineEnding, final OutputStream output,
            final String encoding) throws IOException {
        if (encoding == null) {
            writeLines(lines, lineEnding, output);
        } else {
            if (lines == null) {
                return;
            }
            if (lineEnding == null) {
                lineEnding = LINE_SEPARATOR;
            }
            for (final Iterator<?> it = lines.iterator(); it.hasNext();) {
                final 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(final Collection<?> lines, String lineEnding, final Writer writer)
            throws IOException {
        if (lines == null) {
            return;
        }
        if (lineEnding == null) {
            lineEnding = LINE_SEPARATOR;
        }
        for (final Iterator<?> it = lines.iterator(); it.hasNext();) {
            final 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(final InputStream input, final OutputStream output) throws IOException {
        final 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(final InputStream input, final OutputStream output) throws IOException {
        final 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(final InputStream input, final Writer output) throws IOException {
        final 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(final InputStream input, final Writer output, final String encoding)
            throws IOException {
        if (encoding == null) {
            copy(input, output);
        } else {
            final 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(final Reader input, final Writer output) throws IOException {
        final 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(final Reader input, final Writer output) throws IOException {
        final 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(final Reader input, final OutputStream output) throws IOException {
        final 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(final Reader input, final OutputStream output, final String encoding)
            throws IOException {
        if (encoding == null) {
            copy(input, output);
        } else {
            final 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) {
            final int ch2 = input2.read();
            if (ch != ch2) {
                return false;
            }
            ch = input1.read();
        }

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

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

}