org.apache.wicket.util.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.wicket.util.io;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.CharArrayWriter;
import java.io.Closeable;
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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* General IO Stream manipulation.
*
* This class provides static utility methods for input/output operations.
*
* - closeQuietly - these method closes any kind of closeable resource, e.g. an input/output
* stream or reader/writer ignoring nulls and exceptions
*
- toXxx - 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 show 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: Apache Avalon (Excalibur)
*
* @author Peter Donald
* @author Jeff Turner
* @author Matthew Hawthorne
* @author Stephen Colebourne
* @author Gareth Davis
*/
public final class IOUtils
{
private static final Logger log = LoggerFactory.getLogger(IOUtils.class);
// NOTE: This class is focused on InputStream, OutputStream, Reader and
// Writer. Each method should take at least one of these as a parameter.
// NOTE: This class should not depend on any other classes
/**
* 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()
{
}
/**
* Closes a closeable. Guards against null closables.
*
* @param closeable
* closeable to close
* @throws IOException
* when close fails
*/
public static void close(final Closeable closeable) throws IOException
{
if (closeable != null)
{
closeable.close();
}
}
/**
* Unconditionally close a Closeable.
*
* closeables can be input or output streams, reader, writers, and much more.
*
* Equivalent to {@link Closeable#close()}, except any exceptions will be ignored. This is
* typically used in finally blocks.
*
* @param closeable
* the Closeable to close, may be null or already closed
*/
public static void closeQuietly(final Closeable closeable)
{
try
{
close(closeable);
}
catch (IOException e)
{
log.debug("closing resource failed: " + e.getMessage(), e);
}
}
/**
* 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(final 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(final 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 1.1
*/
public static byte[] toByteArray(final Reader input, final String encoding) throws IOException
{
ByteArrayOutputStream output = new ByteArrayOutputStream();
copy(input, output, encoding);
return output.toByteArray();
}
/**
* 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
*/
public static char[] toCharArray(final 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
*/
public static char[] toCharArray(final InputStream is, final 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
*/
public static char[] toCharArray(final Reader input) throws IOException
{
CharArrayWriter sw = new CharArrayWriter();
copy(input, sw);
return sw.toCharArray();
}
/**
* 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(final 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(final InputStream input, final 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(final Reader input) throws IOException
{
StringWriter sw = new StringWriter();
copy(input, sw);
return sw.toString();
}
/**
* 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 1.1
*/
public static void write(final byte[] data, final 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 1.1
*/
public static void write(final byte[] data, final Writer output) throws IOException
{
if (data != null)
{
output.write(new String(data));
}
}
/**
* Writes bytes from a 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 1.1
*/
public static void write(final byte[] data, final Writer output, final String encoding)
throws IOException
{
if (data != null)
{
if (encoding == null)
{
write(data, output);
}
else
{
output.write(new String(data, encoding));
}
}
}
/**
* 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 1.1
*/
public static void write(final char[] data, final 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 1.1
*/
public static void write(final char[] data, final OutputStream output) throws IOException
{
if (data != null)
{
output.write(new String(data).getBytes());
}
}
/**
* Writes chars from a 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 1.1
*/
public static void write(final char[] data, final OutputStream output, final String encoding)
throws IOException
{
if (data != null)
{
if (encoding == null)
{
write(data, output);
}
else
{
output.write(new String(data).getBytes(encoding));
}
}
}
/**
* 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 1.1
*/
public static void write(final String data, final 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 1.1
*/
public static void write(final String data, final OutputStream output) throws IOException
{
if (data != null)
{
output.write(data.getBytes());
}
}
/**
* Writes chars from a 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 1.1
*/
public static void write(final String data, final OutputStream output, final String encoding)
throws IOException
{
if (data != null)
{
if (encoding == null)
{
write(data, output);
}
else
{
output.write(data.getBytes(encoding));
}
}
}
/**
* Writes chars from a AppendingStringBuffer to a Writer.
*
* @param data
* the AppendingStringBuffer 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 1.1
*/
public static void write(final StringBuilder data, final Writer output) throws IOException
{
if (data != null)
{
output.write(data.toString());
}
}
/**
* Writes chars from a AppendingStringBuffer to bytes on an
* OutputStream using the default character encoding of the platform.
*
* This method uses {@link String#getBytes()}.
*
* @param data
* the AppendingStringBuffer 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 1.1
*/
public static void write(final StringBuilder data, final OutputStream output)
throws IOException
{
if (data != null)
{
output.write(data.toString().getBytes());
}
}
/**
* Writes chars from a AppendingStringBuffer 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 AppendingStringBuffer 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 1.1
*/
public static void write(final StringBuilder data, final OutputStream output,
final String encoding) throws IOException
{
if (data != null)
{
if (encoding == null)
{
write(data, output);
}
else
{
output.write(data.toString().getBytes(encoding));
}
}
}
/**
* Copy bytes from an 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 1.1
*/
public static int copy(final InputStream input, final 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;
}
/**
* 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 1.1
*/
public static void copy(final InputStream input, final 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 1.1
*/
public static void copy(final InputStream input, final Writer output, final String encoding)
throws IOException
{
if (encoding == null)
{
copy(input, output);
}
else
{
InputStreamReader in = new InputStreamReader(input, encoding);
copy(in, output);
}
}
/**
* Copy chars from a 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 1.1
*/
public static int copy(final Reader input, final 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;
}
/**
* 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 1.1
*/
public static void copy(final Reader input, final OutputStream output) throws IOException
{
OutputStreamWriter out = new OutputStreamWriter(output);
copy(input, out);
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 1.1
*/
public static void copy(final Reader input, final OutputStream output, final String encoding)
throws IOException
{
if (encoding == null)
{
copy(input, output);
}
else
{
OutputStreamWriter out = new OutputStreamWriter(output, encoding);
copy(input, out);
out.flush();
}
}
/**
* 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 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);
}
}