org.apache.commons.io.IOUtils 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 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.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayWriter;
import java.io.Closeable;
import java.io.EOFException;
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.Writer;
import java.net.Socket;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.commons.io.output.StringBuilderWriter;
/**
* 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 Sandy McArthur
* @version $Id: IOUtils.java 1091653 2011-04-13 05:22:45Z ggregory $
*/
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
StringBuilderWriter buf = new StringBuilderWriter(4);
PrintWriter out = new PrintWriter(buf);
out.println();
LINE_SEPARATOR = buf.toString();
out.close();
}
/**
* The default buffer size to use for
* {@link #copyLarge(InputStream, OutputStream)}
* and
* {@link #copyLarge(Reader, Writer)}
*/
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
/**
* The default buffer size to use for the skip() methods.
*/
private static final int SKIP_BUFFER_SIZE = 2048;
// Allocated in the skip method if necessary.
private static char[] SKIP_CHAR_BUFFER;
private static byte[] SKIP_BYTE_BUFFER;
/**
* 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.
*
* Example code:
*
* char[] data = new char[1024];
* Reader in = null;
* try {
* in = new FileReader("foo.txt");
* in.read(data);
* in.close(); //close errors are handled
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(in);
* }
*
*
* @param input the Reader to close, may be null or already closed
*/
public static void closeQuietly(Reader input) {
closeQuietly((Closeable)input);
}
/**
* Unconditionally close a Writer.
*
* Equivalent to {@link Writer#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* Example code:
*
* Writer out = null;
* try {
* out = new StringWriter();
* out.write("Hello World");
* out.close(); //close errors are handled
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(out);
* }
*
*
* @param output the Writer to close, may be null or already closed
*/
public static void closeQuietly(Writer output) {
closeQuietly((Closeable)output);
}
/**
* Unconditionally close an InputStream.
*
* Equivalent to {@link InputStream#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* Example code:
*
* byte[] data = new byte[1024];
* InputStream in = null;
* try {
* in = new FileInputStream("foo.txt");
* in.read(data);
* in.close(); //close errors are handled
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(in);
* }
*
*
* @param input the InputStream to close, may be null or already closed
*/
public static void closeQuietly(InputStream input) {
closeQuietly((Closeable)input);
}
/**
* Unconditionally close an OutputStream.
*
* Equivalent to {@link OutputStream#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* Example code:
*
* byte[] data = "Hello, World".getBytes();
*
* OutputStream out = null;
* try {
* out = new FileOutputStream("foo.txt");
* out.write(data);
* out.close(); //close errors are handled
* } catch (IOException e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(out);
* }
*
*
* @param output the OutputStream to close, may be null or already closed
*/
public static void closeQuietly(OutputStream output) {
closeQuietly((Closeable)output);
}
/**
* Unconditionally close a Closeable.
*
* Equivalent to {@link Closeable#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* Example code:
*
* Closeable closeable = null;
* try {
* closeable = new FileReader("foo.txt");
* // process closeable
* closeable.close();
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(closeable);
* }
*
*
* @param closeable the object to close, may be null or already closed
* @since Commons IO 2.0
*/
public static void closeQuietly(Closeable closeable) {
try {
if (closeable != null) {
closeable.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Unconditionally close a Socket.
*
* Equivalent to {@link Socket#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* Example code:
*
* Socket socket = null;
* try {
* socket = new Socket("http://www.foo.com/", 80);
* // process socket
* socket.close();
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(socket);
* }
*
*
* @param sock the Socket to close, may be null or already closed
* @since Commons IO 2.0
*/
public static void closeQuietly(Socket sock){
if (sock != null){
try {
sock.close();
} catch (IOException ioe) {
// ignored
}
}
}
/**
* Fetches entire contents of an InputStream and represent
* same data as result InputStream.
*
* This method is useful where,
*
* - Source InputStream is slow.
* - It has network resources associated, so we cannot keep it open for
* long time.
* - It has network timeout associated.
*
* It can be used in favor of {@link #toByteArray(InputStream)}, since it
* avoids unnecessary allocation and copy of byte[].
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input Stream to be fully buffered.
* @return A fully buffered stream.
* @throws IOException if an I/O error occurs
* @since Commons IO 2.0
*/
public static InputStream toBufferedInputStream(InputStream input) throws IOException {
return ByteArrayOutputStream.toBufferedInputStream(input);
}
// 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 contents of an InputStream as a byte[].
* Use this method instead of toByteArray(InputStream)
* when InputStream size is known.
* NOTE: the method checks that the length can safely be cast to an int without truncation
* before using {@link IOUtils#toByteArray(java.io.InputStream, int)} to read into the byte array.
* (Arrays can have no more than Integer.MAX_VALUE entries anyway)
*
* @param input the InputStream to read from
* @param size the size of InputStream
* @return the requested byte array
* @throws IOException if an I/O error occurs or InputStream size differ from parameter size
* @throws IllegalArgumentException if size is less than zero or size is greater than Integer.MAX_VALUE
* @see IOUtils#toByteArray(java.io.InputStream, int)
* @since Commons IO 2.1
*/
public static byte[] toByteArray(InputStream input, long size) throws IOException {
if(size > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Size cannot be greater than Integer max value: " + size);
}
return toByteArray(input, (int) size);
}
/**
* Get the contents of an InputStream as a byte[].
* Use this method instead of toByteArray(InputStream)
* when InputStream size is known
* @param input the InputStream to read from
* @param size the size of InputStream
* @return the requested byte array
* @throws IOException if an I/O error occurs or InputStream size differ from parameter size
* @throws IllegalArgumentException if size is less than zero
* @since Commons IO 2.1
*/
public static byte[] toByteArray(InputStream input, int size) throws IOException {
if(size < 0) {
throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
}
if(size == 0) {
return new byte[0];
}
byte[] data = new byte[size];
int offset = 0;
int readed;
while(offset < size && (readed = input.read(data, offset, (size - offset))) != -1) {
offset += readed;
}
if(offset != size) {
throw new IOException("Unexpected readed size. current: " + offset + ", excepted: " + size);
}
return data;
}
/**
* 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();
}
// 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 {
return toString(input, null);
}
/**
* 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 {
StringBuilderWriter sw = new StringBuilderWriter();
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 {
StringBuilderWriter sw = new StringBuilderWriter();
copy(input, sw);
return sw.toString();
}
/**
* Gets the contents at the given URI.
*
* @param uri
* The URI source.
* @return The contents of the URL as a String.
* @throws IOException if an I/O exception occurs.
* @since 2.1.
*/
public static String toString(URI uri) throws IOException {
return toString(uri, null);
}
/**
* Gets the contents at the given URI.
*
* @param uri
* The URI source.
* @param encoding
* The encoding name for the URL contents.
* @return The contents of the URL as a String.
* @throws IOException if an I/O exception occurs.
* @since 2.1.
*/
public static String toString(URI uri, String encoding) throws IOException {
return toString(uri.toURL(), encoding);
}
/**
* Gets the contents at the given URL.
*
* @param url
* The URL source.
* @return The contents of the URL as a String.
* @throws IOException if an I/O exception occurs.
* @since 2.1.
*/
public static String toString(URL url) throws IOException {
return toString(url, null);
}
/**
* Gets the contents at the given URL.
*
* @param url
* The URL source.
* @param encoding
* The encoding name for the URL contents.
* @return The contents of the URL as a String.
* @throws IOException if an I/O exception occurs.
* @since 2.1.
*/
public static String toString(URL url, String encoding) throws IOException {
InputStream inputStream = url.openStream();
try {
return toString(inputStream, encoding);
} finally {
inputStream.close();
}
}
/**
* 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);
}
/**
* 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 (encoding == null) {
return new String(input);
} 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);
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;
}
// lineIterator
//-----------------------------------------------------------------------
/**
* Return an Iterator for the lines in a Reader.
*
* LineIterator holds a reference to the open
* Reader specified here. When you have finished with the
* iterator you should close the reader to free internal resources.
* This can be done by closing the reader directly, or by calling
* {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
*
* The recommended usage pattern is:
*
* try {
* LineIterator it = IOUtils.lineIterator(reader);
* while (it.hasNext()) {
* String line = it.nextLine();
* /// do something with line
* }
* } finally {
* IOUtils.closeQuietly(reader);
* }
*
*
* @param reader the Reader to read from, not null
* @return an Iterator of the lines in the reader, never null
* @throws IllegalArgumentException if the reader is null
* @since Commons IO 1.2
*/
public static LineIterator lineIterator(Reader reader) {
return new LineIterator(reader);
}
/**
* Return an Iterator for the lines in an InputStream, using
* the character encoding specified (or default encoding if null).
*
* LineIterator holds a reference to the open
* InputStream specified here. When you have finished with
* the iterator you should close the stream to free internal resources.
* This can be done by closing the stream directly, or by calling
* {@link LineIterator#close()} or {@link LineIterator#closeQuietly(LineIterator)}.
*
* The recommended usage pattern is:
*
* try {
* LineIterator it = IOUtils.lineIterator(stream, "UTF-8");
* while (it.hasNext()) {
* String line = it.nextLine();
* /// do something with line
* }
* } finally {
* IOUtils.closeQuietly(stream);
* }
*
*
* @param input the InputStream to read from, not null
* @param encoding the encoding to use, null means platform default
* @return an Iterator of the lines in the reader, never null
* @throws IllegalArgumentException if the input is null
* @throws IOException if an I/O error occurs, such as if the encoding is invalid
* @since Commons IO 1.2
*/
public static LineIterator lineIterator(InputStream input, String encoding)
throws IOException {
Reader reader = null;
if (encoding == null) {
reader = new InputStreamReader(input);
} else {
reader = new InputStreamReader(input, encoding);
}
return new LineIterator(reader);
}
//-----------------------------------------------------------------------
/**
* 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 Commons 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 Commons 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();
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();
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));
}
}
/**
* 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());
}
}
/**
* 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());
}
}
/**
* 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());
}
}
/**
* 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));
}
}
}
// writeLines
//-----------------------------------------------------------------------
/**
* Writes the toString() value of each item in a collection to
* an OutputStream 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 OutputStream to write to, not null, not closed
* @throws NullPointerException if the output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
OutputStream output) throws IOException {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Object line : lines) {
if (line != null) {
output.write(line.toString().getBytes());
}
output.write(lineEnding.getBytes());
}
}
/**
* Writes the toString() value of each item in a collection to
* an OutputStream line by line, using the specified character
* encoding and the specified line ending.
*
* Character encoding names can be found at
* IANA.
*
* @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 OutputStream to write to, not null, not closed
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if the output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
OutputStream output, String encoding) throws IOException {
if (encoding == null) {
writeLines(lines, lineEnding, output);
} else {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Object line : lines) {
if (line != null) {
output.write(line.toString().getBytes(encoding));
}
output.write(lineEnding.getBytes(encoding));
}
}
}
/**
* Writes the toString() value of each item in a collection to
* a Writer 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 Writer to write to, not null, not closed
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
Writer writer) throws IOException {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Object line : lines) {
if (line != null) {
writer.write(line.toString());
}
writer.write(lineEnding);
}
}
// 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, or -1 if > Integer.MAX_VALUE
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @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);
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, or -1 if > Integer.MAX_VALUE
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @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);
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);
}
/**
* Skip 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
* subclasses of {@link Reader}.
*
* @param input byte stream to skip
* @param toSkip number of bytes to skip.
* @return number of bytes actually skipped.
*
* @see InputStream#skip(long)
*
* @throws IOException if there is a problem reading the file
* @throws IllegalArgumentException if toSkip is negative
* @since Commons IO 2.0
*/
public static long skip(InputStream input, 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) {
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;
}
/**
* Skip characters from an input character stream.
* This implementation guarantees that it will read as many characters
* as possible before giving up; this may not always be the case for
* subclasses of {@link Reader}.
*
* @param input character stream to skip
* @param toSkip number of characters to skip.
* @return number of characters actually skipped.
*
* @see Reader#skip(long)
*
* @throws IOException if there is a problem reading the file
* @throws IllegalArgumentException if toSkip is negative
* @since Commons IO 2.0
*/
public static long skip(Reader input, 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_CHAR_BUFFER == null){
SKIP_CHAR_BUFFER = new char[SKIP_BUFFER_SIZE];
}
long remain=toSkip;
while(remain > 0) {
long n = input.read(SKIP_CHAR_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
if (n < 0) { // EOF
break;
}
remain -= n;
}
return toSkip - remain;
}
/**
* Skip the requested number of bytes or fail if there are not enough left.
*
* This allows for the possibility that {@link InputStream#skip(long)} may
* not skip as many bytes as requested (most likely because of reaching EOF).
*
* @param input stream to skip
* @param toSkip the number of bytes to skip
* @see InputStream#skip(long)
*
* @throws IOException if there is a problem reading the file
* @throws IllegalArgumentException if toSkip is negative
* @throws EOFException if the number of bytes skipped was incorrect
* @since Commons IO 2.0
*/
public static void skipFully(InputStream input, long toSkip) throws IOException {
if (toSkip < 0){
throw new IllegalArgumentException("Bytes to skip must not be negative: "+toSkip);
}
long skipped = skip(input, toSkip);
if (skipped != toSkip) {
throw new EOFException("Bytes to skip: "+toSkip+" actual: "+skipped);
}
}
/**
* Skip the requested number of characters or fail if there are not enough left.
*
* This allows for the possibility that {@link Reader#skip(long)} may
* not skip as many characters as requested (most likely because of reaching EOF).
*
* @param input stream to skip
* @param toSkip the number of characters to skip
* @see Reader#skip(long)
*
* @throws IOException if there is a problem reading the file
* @throws IllegalArgumentException if toSkip is negative
* @throws EOFException if the number of characters skipped was incorrect
* @since Commons IO 2.0
*/
public static void skipFully(Reader input, long toSkip) throws IOException {
long skipped = skip(input, toSkip);
if (skipped != toSkip) {
throw new EOFException("Bytes to skip: "+toSkip+" actual: "+skipped);
}
}
}