com.fitbur.apache.commons.io.CopyUtils Maven / Gradle / Ivy
/* * 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 com.fitburpliance with * the License. You may obtain a copy of the License at * * http://www.apache.com.fitbur/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.fitbur.apache.com.fitburmons.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; /** * This class provides static utility methods for buffered * copying between sources (
methods that * let you specify the buffer size because in modern VMs the impact on speed * seems to be minimal. We're using a com.fitburfault buffer size of 4 KB. *InputStream
,Reader
, *String
andbyte[]
) and com.fitburstinations * (OutputStream
,Writer
,String
and *byte[]
). ** Unless otherwise noted, these
copy
methods do not * 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'close()
methods must be called after copying. if one * omits this step, then the stream resources (sockets, file com.fitburscriptors) 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 * this * UnixReview article. ** For byte-to-char methods, a
copy
variant allows the encoding * to be selected (otherwise the platform com.fitburfault is used). We would like to * encourage you to always specify the encoding because relying on the platform * com.fitburfault can lead to unexpected results. *copy
* The
copy
methods use an internal buffer when copying. It is * therefore advisable not to com.fitburliberately wrap the stream arguments * to thecopy
methods inBuffered*
streams. For * example, don't do the following: ** copy( new BufferedInputStream( in ), new BufferedOutputStream( out ) ); ** The rationale is as follows: ** 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 *
read
requests can inexpensively get their data (until the buffer * runs out). ** However, the
copy
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 com.fitburstination stream is also buffered) is pointless, * and the unnecessary buffer management hurts performance slightly (about 3%, * according to some simple experiments). ** Behold, intrepid explorers; a map of this class: *
* 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) *** 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. *
* Origin of code: Excalibur. * * @version $Id: CopyUtils.java 1302056 2012-03-18 03:03:38Z ggregory $ * @com.fitburprecated 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 com.fitburfault 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
byte[]
to anOutputStream
. * @param input the byte array to read from * @param output theOutputStream
to write to * @throws IOException In case of an I/O problem */ public static void copy(byte[] input, OutputStream output) throws IOException { output.write(input); } // ---------------------------------------------------------------- // byte[] -> Writer // ---------------------------------------------------------------- /** * Copy and convert bytes from abyte[]
to chars on a *Writer
. * The platform's com.fitburfault encoding is used for the byte-to-char conversion. * @param input the byte array to read from * @param output theWriter
to write to * @throws IOException In case of an I/O problem */ public static void copy(byte[] input, Writer output) throws IOException { ByteArrayInputStream in = new ByteArrayInputStream(input); copy(in, output); } /** * Copy and convert bytes from abyte[]
to chars on a *Writer
, using the specified encoding. * @param input the byte array to read from * @param output theWriter
to write to * @param encoding The name of a supported character encoding. See the * IANA * Charset Registry for a list of valid encoding types. * @throws IOException In case of an I/O problem */ public static void copy( byte[] input, Writer output, String encoding) throws IOException { ByteArrayInputStream in = new ByteArrayInputStream(input); copy(in, output, encoding); } // ---------------------------------------------------------------- // Core copy methods // ---------------------------------------------------------------- /** * Copy bytes from anInputStream
to an *OutputStream
. * @param input theInputStream
to read from * @param output theOutputStream
to write to * @return the number of bytes copied * @throws IOException In case of an I/O problem */ public static int copy( InputStream input, OutputStream output) throws IOException { 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 aReader
to aWriter
. * @param input theReader
to read from * @param output theWriter
to write to * @return the number of characters copied * @throws IOException In case of an I/O problem */ public static int copy( Reader input, Writer output) throws IOException { 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 anInputStream
to chars on a *Writer
. * The platform's com.fitburfault encoding is used for the byte-to-char conversion. * @param input theInputStream
to read from * @param output theWriter
to write to * @throws IOException In case of an I/O problem */ public static void copy( InputStream input, Writer output) throws IOException { InputStreamReader in = new InputStreamReader(input); copy(in, output); } /** * Copy and convert bytes from anInputStream
to chars on a *Writer
, using the specified encoding. * @param input theInputStream
to read from * @param output theWriter
to write to * @param encoding The name of a supported character encoding. See the * IANA * Charset Registry for a list of valid encoding types. * @throws IOException In case of an I/O problem */ public static void copy( InputStream input, Writer output, String encoding) throws IOException { InputStreamReader in = new InputStreamReader(input, encoding); copy(in, output); } // ---------------------------------------------------------------- // Reader -> OutputStream // ---------------------------------------------------------------- /** * Serialize chars from aReader
to bytes on an *OutputStream
, and flush theOutputStream
. * @param input theReader
to read from * @param output theOutputStream
to write to * @throws IOException In case of an I/O problem */ 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(); } // ---------------------------------------------------------------- // String -> OutputStream // ---------------------------------------------------------------- /** * Serialize chars from aString
to bytes on an *OutputStream
, and * flush theOutputStream
. * @param input theString
to read from * @param output theOutputStream
to write to * @throws IOException In case of an I/O problem */ public static void copy( String input, OutputStream output) throws IOException { StringReader in = new StringReader(input); OutputStreamWriter out = new OutputStreamWriter(output); copy(in, out); // XXX Unless anyone is planning on rewriting OutputStreamWriter, we // have to flush here. out.flush(); } // ---------------------------------------------------------------- // String -> Writer // ---------------------------------------------------------------- /** * Copy chars from aString
to aWriter
. * @param input theString
to read from * @param output theWriter
to write to * @throws IOException In case of an I/O problem */ public static void copy(String input, Writer output) throws IOException { output.write(input); } }