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/*
* 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.tika.io;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.CharArrayWriter;
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.StringWriter;
import java.io.Writer;
import java.nio.channels.Channel;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;
/**
* General IO stream manipulation utilities.
*
* This class provides static utility methods for input/output operations.
*
* - closeQuietly - these methods close a stream ignoring nulls and exceptions
*
- toXxx/read - these methods read data from a stream
*
- write - these methods write data to a stream
*
- copy - these methods copy all the data from one stream to another
*
- contentEquals - these methods compare the content of two streams
*
*
* The byte-to-char methods and char-to-byte methods involve a conversion step.
* Two methods are provided in each case, one that uses the platform default
* encoding and the other which allows you to specify an encoding. You are
* encouraged to always specify an encoding because relying on the platform
* default can lead to unexpected results, for example when moving from
* development to production.
*
* All the methods in this class that read a stream are buffered internally.
* This means that there is no cause to use a BufferedInputStream
* or BufferedReader. The default buffer size of 4K has been shown
* to be efficient in tests.
*
* Wherever possible, the methods in this class do not flush or close
* the stream. This is to avoid making non-portable assumptions about the
* streams' origin and further use. Thus the caller is still responsible for
* closing streams after use.
*
* Origin of code: Excalibur.
*
* @author Peter Donald
* @author Jeff Turner
* @author Matthew Hawthorne
* @author Stephen Colebourne
* @author Gareth Davis
* @author Ian Springer
* @author Niall Pemberton
* @author Sandy McArthur
* @since Apache Tika 0.4, copied (partially) from Commons IO 1.4
*/
public class IOUtils {
// TODO Remove this when we've finished TIKA-1706 and TIKA-1710
public static final Charset UTF_8 = java.nio.charset.StandardCharsets.UTF_8;
/**
* The default buffer size to use for the skip() methods.
*/
private static final int SKIP_BUFFER_SIZE = 2048;
private static byte[] SKIP_BYTE_BUFFER;
/**
* The default buffer size to use.
*/
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
/**
* Instances should NOT be constructed in standard programming.
*/
public IOUtils() {
super();
}
//-----------------------------------------------------------------------
/**
* Unconditionally close an Reader.
*
* 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 Channel.
*
* Equivalent to {@link Channel#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* @param channel the Channel to close, may be null or already closed
*/
public static void closeQuietly(Channel channel) {
try {
if (channel != null) {
channel.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Unconditionally close a Writer.
*
* 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 InputStream.
*
* 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 OutputStream.
*
* 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 InputStream as a byte[].
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream 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 Reader as a byte[]
* using the default character encoding of the platform.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader 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 Reader as a byte[]
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader 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 String as a byte[]
* using the default character encoding of the platform.
*
* This is the same as {@link String#getBytes()}.
*
* @param input the String 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(String input) throws IOException {
return input.getBytes(UTF_8);
}
// read char[]
//-----------------------------------------------------------------------
/**
* Get the contents of an InputStream as a character array
* using the default character encoding of the platform.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param is the InputStream 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 InputStream as a character array
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param is the InputStream 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 Reader as a character array.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader 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 InputStream as a String
* using the default character encoding of the platform.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream 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 InputStream as a String
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream 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 Reader as a String.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader 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 byte[] 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[])}
*/
@Deprecated
public static String toString(byte[] input) throws IOException {
return new String(input, UTF_8);
}
/**
* Get the contents of a byte[] as a String
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* @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)}
*/
@Deprecated
public static String toString(byte[] input, String encoding)
throws IOException {
// If no encoding is specified, default to UTF-8.
if (encoding == null) {
return new String(input, UTF_8);
} else {
return new String(input, encoding);
}
}
// readLines
//-----------------------------------------------------------------------
/**
* Get the contents of an InputStream as a list of Strings,
* one entry per line, using the default character encoding of the platform.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream 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, UTF_8);
return readLines(reader);
}
/**
* Get the contents of an InputStream as a list of Strings,
* one entry per line, using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream 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 Reader as a list of Strings,
* one entry per line.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader 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 CharSequence to an input stream, encoded as bytes
* using the default character encoding of the platform.
*
* @param input the CharSequence to convert
* @return an input stream
* @since IO 2.0
*/
public static InputStream toInputStream(CharSequence input) {
return toInputStream(input.toString());
}
/**
* Convert the specified CharSequence to an input stream, encoded as bytes
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* @param input the CharSequence to convert
* @param encoding the encoding to use, null means platform default
* @throws IOException if the encoding is invalid
* @return an input stream
* @since IO 2.0
*/
public static InputStream toInputStream(CharSequence input, String encoding) throws IOException {
return toInputStream(input.toString(), encoding);
}
//-----------------------------------------------------------------------
/**
* 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(UTF_8);
return new ByteArrayInputStream(bytes);
}
/**
* Convert the specified string to an input stream, encoded as bytes
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* @param input the string to convert
* @param encoding the encoding to use, null means platform default
* @throws IOException if the encoding is invalid
* @return an input stream
* @since Commons IO 1.1
*/
public static InputStream toInputStream(String input, String encoding) throws IOException {
byte[] bytes = encoding != null ? input.getBytes(encoding) : input.getBytes(UTF_8);
return new ByteArrayInputStream(bytes);
}
// write byte[]
//-----------------------------------------------------------------------
/**
* Writes bytes from a byte[] to an OutputStream.
*
* @param data the byte array to write, do not modify during output,
* null ignored
* @param output the OutputStream 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 byte[] to chars on a Writer
* using the default character encoding of the platform.
*
* This method uses {@link String#String(byte[])}.
*
* @param data the byte array to write, do not modify during output,
* null ignored
* @param output the Writer 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, UTF_8));
}
}
/**
* Writes bytes from a byte[] to chars on a Writer
* using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* 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 Writer 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 char[] to a Writer
* 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 Writer 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 char[] to bytes on an
* OutputStream.
*
* 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 OutputStream 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(UTF_8));
}
}
/**
* Writes chars from a char[] to bytes on an
* OutputStream using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* 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 OutputStream 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 CharSequence
//-----------------------------------------------------------------------
/**
* Writes chars from a CharSequence to a Writer.
*
* @param data the CharSequence to write, null ignored
* @param output the Writer to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 2.0
*/
public static void write(CharSequence data, Writer output) throws IOException {
if (data != null) {
write(data.toString(), output);
}
}
/**
* Writes chars from a CharSequence to bytes on an
* OutputStream using the default character encoding of the
* platform.
*
* This method uses {@link String#getBytes()}.
*
* @param data the CharSequence to write, null ignored
* @param output the OutputStream to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 2.0
*/
public static void write(CharSequence data, OutputStream output)
throws IOException {
if (data != null) {
write(data.toString(), output);
}
}
/**
* Writes chars from a CharSequence to bytes on an
* OutputStream using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method uses {@link String#getBytes(String)}.
*
* @param data the CharSequence to write, null ignored
* @param output the OutputStream 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 2.0
*/
public static void write(CharSequence data, OutputStream output, String encoding)
throws IOException {
if (data != null) {
write(data.toString(), output, encoding);
}
}
// write String
//-----------------------------------------------------------------------
/**
* Writes chars from a String to a Writer.
*
* @param data the String to write, null ignored
* @param output the Writer 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 String to bytes on an
* OutputStream using the default character encoding of the
* platform.
*
* This method uses {@link String#getBytes()}.
*
* @param data the String to write, null ignored
* @param output the OutputStream 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(UTF_8));
}
}
/**
* Writes chars from a String to bytes on an
* OutputStream using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method uses {@link String#getBytes(String)}.
*
* @param data the String to write, null ignored
* @param output the OutputStream 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 StringBuffer to a Writer.
*
* @param data the StringBuffer to write, null ignored
* @param output the Writer to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
* @deprecated replaced by write(CharSequence, Writer)
*/
@Deprecated
public static void write(StringBuffer data, Writer output)
throws IOException {
if (data != null) {
output.write(data.toString());
}
}
/**
* Writes chars from a StringBuffer to bytes on an
* OutputStream using the default character encoding of the
* platform.
*
* This method uses {@link String#getBytes()}.
*
* @param data the StringBuffer to write, null ignored
* @param output the OutputStream to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
* @deprecated replaced by write(CharSequence, OutputStream)
*/
@Deprecated
public static void write(StringBuffer data, OutputStream output)
throws IOException {
if (data != null) {
output.write(data.toString().getBytes(UTF_8));
}
}
/**
* Writes chars from a StringBuffer to bytes on an
* OutputStream using the specified character encoding.
*
* Character encoding names can be found at
* IANA.
*
* This method uses {@link String#getBytes(String)}.
*
* @param data the StringBuffer to write, null ignored
* @param output the OutputStream 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
* @deprecated replaced by write(CharSequence, OutputStream, String)
*/
@Deprecated
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));
}
}
}
// copy from InputStream
//-----------------------------------------------------------------------
/**
* Copy bytes from an InputStream to an
* OutputStream.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* Large streams (over 2GB) will return a bytes copied value of
* -1 after the copy has completed since the correct
* number of bytes cannot be returned as an int. For large streams
* use the copyLarge(InputStream, OutputStream) method.
*
* @param input the InputStream to read from
* @param output the OutputStream 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) InputStream to an
* OutputStream.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input the InputStream to read from
* @param output the OutputStream 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 InputStream to chars on a
* Writer using the default character encoding of the platform.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* This method uses {@link InputStreamReader}.
*
* @param input the InputStream to read from
* @param output the Writer 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, UTF_8);
copy(in, output);
}
/**
* Copy bytes from an InputStream to chars on a
* Writer using the specified character encoding.
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* Character encoding names can be found at
* IANA.
*
* This method uses {@link InputStreamReader}.
*
* @param input the InputStream to read from
* @param output the Writer 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 Reader to a Writer.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* Large streams (over 2GB) will return a chars copied value of
* -1 after the copy has completed since the correct
* number of chars cannot be returned as an int. For large streams
* use the copyLarge(Reader, Writer) method.
*
* @param input the Reader to read from
* @param output the Writer 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) Reader to a Writer.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* @param input the Reader to read from
* @param output the Writer 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 Reader to bytes on an
* OutputStream using the default character encoding of the
* platform, and calling flush.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* Due to the implementation of OutputStreamWriter, this method performs a
* flush.
*
* This method uses {@link OutputStreamWriter}.
*
* @param input the Reader to read from
* @param output the OutputStream 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, UTF_8);
copy(input, out);
// XXX Unless anyone is planning on rewriting OutputStreamWriter, we
// have to flush here.
out.flush();
}
/**
* Copy chars from a Reader to bytes on an
* OutputStream using the specified character encoding, and
* calling flush.
*
* This method buffers the input internally, so there is no need to use a
* BufferedReader.
*
* Character encoding names can be found at
* IANA.
*
* Due to the implementation of OutputStreamWriter, this method performs a
* flush.
*
* This method uses {@link OutputStreamWriter}.
*
* @param input the Reader to read from
* @param output the OutputStream 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.
*
* This method buffers the input internally using
* BufferedInputStream 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.
*
* This method buffers the input internally using
* BufferedReader 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);
}
/**
* Reads bytes from an input stream.
* This implementation guarantees that it will read as many bytes
* as possible before giving up; this may not always be the case for
* subclasses of {@link InputStream}.
*
* @param input where to read input from
* @param buffer destination
* @param offset initial offset into buffer
* @param length length to read, must be >= 0
* @return actual length read; may be less than requested if EOF was reached
* @throws IOException if a read error occurs
* @since 2.2
*/
public static int read(final InputStream input, final byte[] buffer, final int offset, final int length)
throws IOException {
if (length < 0) {
throw new IllegalArgumentException("Length must not be negative: " + length);
}
int remaining = length;
while (remaining > 0) {
final int location = length - remaining;
final int count = input.read(buffer, offset + location, remaining);
if (count == -1) { // EOF
break;
}
remaining -= count;
}
return length - remaining;
}
/**
* Skips bytes from an input byte stream.
* This implementation guarantees that it will read as many bytes
* as possible before giving up; this may not always be the case for
* skip() implementations in subclasses of {@link InputStream}.
*
* Note that the implementation uses {@link InputStream#read(byte[], int, int)} rather
* than delegating to {@link InputStream#skip(long)}.
* This means that the method may be considerably less efficient than using the actual skip implementation,
* this is done to guarantee that the correct number of bytes are skipped.
*
*
* @param input byte stream to skip
* @param toSkip number of bytes to skip.
* @return number of bytes actually skipped.
* @throws IOException if there is a problem reading the file
* @throws IllegalArgumentException if toSkip is negative
* @see InputStream#skip(long)
* @see IO-203 - Add skipFully() method for InputStreams
*/
public static long skip(final InputStream input, final long toSkip) throws IOException {
if (toSkip < 0) {
throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
}
/*
* N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
* is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
* size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
*/
if (SKIP_BYTE_BUFFER == null) {
SKIP_BYTE_BUFFER = new byte[SKIP_BUFFER_SIZE];
}
long remain = toSkip;
while (remain > 0) {
// See https://issues.apache.org/jira/browse/IO-203 for why we use read() rather than delegating to skip()
final long n = input.read(SKIP_BYTE_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
if (n < 0) { // EOF
break;
}
remain -= n;
}
return toSkip - remain;
}
public static long skip(final InputStream input, final long toSkip, byte[] buffer) throws IOException {
if (toSkip < 0) {
throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
}
/*
* N.B. no need to synchronize this because: - we don't care if the buffer is created multiple times (the data
* is ignored) - we always use the same size buffer, so if it it is recreated it will still be OK (if the buffer
* size were variable, we would need to synch. to ensure some other thread did not create a smaller one)
*/
long remain = toSkip;
while (remain > 0) {
// See https://issues.apache.org/jira/browse/IO-203 for why we use read() rather than delegating to skip()
final long n = input.read(buffer, 0, (int) Math.min(remain, buffer.length));
if (n < 0) { // EOF
break;
}
remain -= n;
}
return toSkip - remain;
}
}