/*

  * 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 org.apache.commons.io;

 import java.io.ByteArrayInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.io.InputStreamReader;

 import java.io.OutputStream;

 import java.io.OutputStreamWriter;

 import java.io.Reader;

 import java.io.StringReader;

 import java.io.Writer;

 import java.nio.charset.Charset;

 /**

  * This class provides static utility methods for buffered

  * copying between sources (<code>InputStream</code>, <code>Reader</code>,

  * <code>String</code> and <code>byte[]</code>) and destinations

  * (<code>OutputStream</code>, <code>Writer</code>, <code>String</code> and

  * <code>byte[]</code>).

  * <p>

  * Unless otherwise noted, these <code>copy</code> methods do <em>not</em>

  * flush or close the streams. Often doing so would require making non-portable

  * assumptions about the streams' origin and further use. This means that both

  * streams' <code>close()</code> methods must be called after copying. if one

  * omits this step, then the stream resources (sockets, file descriptors) are

  * released when the associated Stream is garbage-collected. It is not a good

  * idea to rely on this mechanism. For a good overview of the distinction

  * between "memory management" and "resource management", see

  * <a href="http://www.unixreview.com/articles/1998/9804/9804ja/ja.htm">this

  * UnixReview article</a>.

  * <p>

  * For byte-to-char methods, a <code>copy</code> variant allows the encoding

  * to be selected (otherwise the platform default is used). We would like to

  * encourage you to always specify the encoding because relying on the platform

  * default can lead to unexpected results.

  * <p

  * We don't provide special variants for the <code>copy</code> methods that

  * let you specify the buffer size because in modern VMs the impact on speed

  * seems to be minimal. We're using a default buffer size of 4 KB.

  * <p>

  * The <code>copy</code> methods use an internal buffer when copying. It is

  * therefore advisable <em>not</em> to deliberately wrap the stream arguments

  * to the <code>copy</code> methods in <code>Buffered*</code> streams. For

  * example, don't do the following:

  * <pre>

  *  copy( new BufferedInputStream( in ), new BufferedOutputStream( out ) );

  *  </pre>

  * The rationale is as follows:

  * <p>

  * Imagine that an InputStream's read() is a very expensive operation, which

  * would usually suggest wrapping in a BufferedInputStream. The

  * BufferedInputStream works by issuing infrequent

  * {@link java.io.InputStream#read(byte[] b, int off, int len)} requests on the

  * underlying InputStream, to fill an internal buffer, from which further

  * <code>read</code> requests can inexpensively get their data (until the buffer

  * runs out).

  * <p>

  * However, the <code>copy</code> methods do the same thing, keeping an

  * internal buffer, populated by

  * {@link InputStream#read(byte[] b, int off, int len)} requests. Having two

  * buffers (or three if the destination stream is also buffered) is pointless,

  * and the unnecessary buffer management hurts performance slightly (about 3%,

  * according to some simple experiments).

  * <p>

  * Behold, intrepid explorers; a map of this class:

  * <pre>

  *       Method      Input               Output          Dependency

  *       ------      -----               ------          -------

  * 1     copy        InputStream         OutputStream    (primitive)

  * 2     copy        Reader              Writer          (primitive)

  *

  * 3     copy        InputStream         Writer          2

  *

  * 4     copy        Reader              OutputStream    2

  *

  * 5     copy        String              OutputStream    2

  * 6     copy        String              Writer          (trivial)

  *

  * 7     copy        byte[]              Writer          3

  * 8     copy        byte[]              OutputStream    (trivial)

  * </pre>

  * <p>

  * Note that only the first two methods shuffle bytes; the rest use these

  * two, or (if possible) copy using native Java copy methods. As there are

  * method variants to specify the encoding, each row may

  * correspond to up to 2 methods.

  * <p>

  * Origin of code: Excalibur.

  *

  * @version $Id: CopyUtils.java 1468991 2013-04-17 16:37:18Z sebb $

  * @deprecated Use IOUtils. Will be removed in 2.0.

  *  Methods renamed to IOUtils.write() or IOUtils.copy().

  *  Null handling behaviour changed in IOUtils (null data does not

  *  throw NullPointerException).

  */

 @Deprecated

 public class CopyUtils {

     /**

      * The default size of the buffer.

      */

     private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;

     /**

      * Instances should NOT be constructed in standard programming.

      */

     public CopyUtils() { }

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

     // byte[] -> OutputStream

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

     /**

      * Copy bytes from a <code>byte[]</code> to an <code>OutputStream</code>.

      * @param input the byte array to read from

      * @param output the <code>OutputStream</code> to write to

      * @throws IOException In case of an I/O problem

      */

     public static void copy(final byte[] input, final OutputStream output)

             throws IOException {

         output.write(input);

     }

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

     // byte[] -> Writer

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

     /**

      * Copy and convert bytes from a <code>byte[]</code> to chars on a

      * <code>Writer</code>.

      * The platform's default encoding is used for the byte-to-char conversion.

      * @param input the byte array to read from

      * @param output the <code>Writer</code> to write to

      * @throws IOException In case of an I/O problem

      * @deprecated 2.5 use {@link #copy(byte[], Writer, String)} instead

      */

     @Deprecated

     public static void copy(final byte[] input, final Writer output)

             throws IOException {

         final ByteArrayInputStream in = new ByteArrayInputStream(input);

         copy(in, output);

     }

     /**

      * Copy and convert bytes from a <code>byte[]</code> to chars on a

      * <code>Writer</code>, using the specified encoding.

      * @param input the byte array to read from

      * @param output the <code>Writer</code> to write to

      * @param encoding The name of a supported character encoding. See the

      * <a href="http://www.iana.org/assignments/character-sets">IANA

      * Charset Registry</a> for a list of valid encoding types.

      * @throws IOException In case of an I/O problem

      */

     public static void copy(

             final byte[] input,

             final Writer output,

             final String encoding)

                 throws IOException {

         final ByteArrayInputStream in = new ByteArrayInputStream(input);

         copy(in, output, encoding);

     }

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

     // Core copy methods

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

     /**

      * Copy bytes from an <code>InputStream</code> to an

      * <code>OutputStream</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 IOException In case of an I/O problem

      */

     public static int copy(

             final InputStream input,

             final OutputStream output)

                 throws IOException {

         final byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];

         int count = 0;

         int n = 0;

         while (-1 != (n = input.read(buffer))) {

             output.write(buffer, 0, n);

             count += n;

         }

         return count;

     }

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

     // Reader -> Writer

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

     /**

      * Copy chars from a <code>Reader</code> to a <code>Writer</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 IOException In case of an I/O problem

      */

     public static int copy(

             final Reader input,

             final Writer output)

                 throws IOException {

         final char[] buffer = new char[DEFAULT_BUFFER_SIZE];

         int count = 0;

         int n = 0;

         while (-1 != (n = input.read(buffer))) {

             output.write(buffer, 0, n);

             count += n;

         }

         return count;

     }

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

     // InputStream -> Writer

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

     /**

      * Copy and convert bytes from an <code>InputStream</code> to chars on a

      * <code>Writer</code>.

      * The platform's default encoding is used for the byte-to-char conversion.

      * @param input the <code>InputStream</code> to read from

      * @param output the <code>Writer</code> to write to

      * @throws IOException In case of an I/O problem

      * @deprecated 2.5 use {@link #copy(InputStream, Writer, String)} instead

      */

     @Deprecated

     public static void copy(

             final InputStream input,

             final Writer output)

                 throws IOException {

         // make explicit the dependency on the default encoding

         final InputStreamReader in = new InputStreamReader(input, Charset.defaultCharset());

         copy(in, output);

     }

     /**

      * Copy and convert bytes from an <code>InputStream</code> to chars on a

      * <code>Writer</code>, using the specified encoding.

      * @param input the <code>InputStream</code> to read from

      * @param output the <code>Writer</code> to write to

      * @param encoding The name of a supported character encoding. See the

      * <a href="http://www.iana.org/assignments/character-sets">IANA

      * Charset Registry</a> for a list of valid encoding types.

      * @throws IOException In case of an I/O problem

      */

     public static void copy(

             final InputStream input,

             final Writer output,

             final String encoding)

                 throws IOException {

         final InputStreamReader in = new InputStreamReader(input, encoding);

         copy(in, output);

     }

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

     // Reader -> OutputStream

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

     /**

      * Serialize chars from a <code>Reader</code> to bytes on an

      * <code>OutputStream</code>, and flush the <code>OutputStream</code>.

      * Uses the default platform encoding.

      * @param input the <code>Reader</code> to read from

      * @param output the <code>OutputStream</code> to write to

      * @throws IOException In case of an I/O problem

      * @deprecated 2.5 use {@link #copy(Reader, OutputStream, String)} instead

      */

     @Deprecated

     public static void copy(

             final Reader input,

             final OutputStream output)

                 throws IOException {

         // make explicit the dependency on the default encoding

         final OutputStreamWriter out = new OutputStreamWriter(output, Charset.defaultCharset());

         copy(input, out);

         // XXX Unless anyone is planning on rewriting OutputStreamWriter, we

         // have to flush here.

         out.flush();

     }

     /**

      * Serialize chars from a <code>Reader</code> to bytes on an

      * <code>OutputStream</code>, and flush the <code>OutputStream</code>.

      * @param input the <code>Reader</code> to read from

      * @param output the <code>OutputStream</code> to write to

      * @throws IOException In case of an I/O problem

      * @since 2.5

      */

     public static void copy(

             final Reader input,

             final OutputStream output,

             final String encoding)

                 throws IOException {

         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();

     }

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

     // String -> OutputStream

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

     /**

      * Serialize chars from a <code>String</code> to bytes on an

      * <code>OutputStream</code>, and

      * flush the <code>OutputStream</code>.

      * Uses the platform default encoding.

      * @param input the <code>String</code> to read from

      * @param output the <code>OutputStream</code> to write to

      * @throws IOException In case of an I/O problem

      * @deprecated 2.5 use {@link #copy(String, OutputStream, String)} instead

      */

     @Deprecated

     public static void copy(

             final String input,

             final OutputStream output)

                 throws IOException {

         final StringReader in = new StringReader(input);

         // make explicit the dependency on the default encoding

         final OutputStreamWriter out = new OutputStreamWriter(output, Charset.defaultCharset());

         copy(in, out);

         // XXX Unless anyone is planning on rewriting OutputStreamWriter, we

         // have to flush here.

         out.flush();

     }

     /**

      * Serialize chars from a <code>String</code> to bytes on an

      * <code>OutputStream</code>, and

      * flush the <code>OutputStream</code>.

      * @param input the <code>String</code> to read from

      * @param output the <code>OutputStream</code> to write to

      * @throws IOException In case of an I/O problem

      * @since 2.5

      */

     public static void copy(

             final String input,

             final OutputStream output,

             final String encoding)

                 throws IOException {

         final StringReader in = new StringReader(input);

         final OutputStreamWriter out = new OutputStreamWriter(output, encoding);

         copy(in, out);

         // XXX Unless anyone is planning on rewriting OutputStreamWriter, we

         // have to flush here.

         out.flush();

     }

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

     // String -> Writer

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

     /**

      * Copy chars from a <code>String</code> to a <code>Writer</code>.

      * @param input the <code>String</code> to read from

      * @param output the <code>Writer</code> to write to

      * @throws IOException In case of an I/O problem

      */

     public static void copy(final String input, final Writer output)

                 throws IOException {

         output.write(input);

     }

 }