org.codehaus.plexus.util.IOUtil Maven / Gradle / Ivy
package org.codehaus.plexus.util;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.codehaus.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache Turbine" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "Apache",
* "Apache Turbine", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
*
* This class provides static utility methods for input/output operations, particularly buffered copying between sources
* (InputStream, Reader, String and byte[]) and destinations
* (OutputStream, Writer, String and byte[]).
*
*
* Unless otherwise noted, these copy methods do not flush or close the streams. Often, doing so
* would require making non-portable assumptions about the streams' origin and further use. This means that both
* streams' close() methods must be called after copying. if one omits this step, then the stream resources
* (sockets, file descriptors) are released when the associated Stream is garbage-collected. It is not a good idea to
* rely on this mechanism. For a good overview of the distinction between "memory management" and "resource management",
* see this UnixReview article
*
*
* For each copy method, a variant is provided that allows the caller to specify the buffer size (the
* default is 4k). As the buffer size can have a fairly large impact on speed, this may be worth tweaking. Often "large
* buffer -> faster" does not hold, even for large data transfers.
*
*
* For byte-to-char methods, a copy variant allows the encoding to be selected (otherwise the platform
* default is used).
*
*
* The copy methods use an internal buffer when copying. It is therefore advisable not to
* deliberately wrap the stream arguments to the copy methods in Buffered* streams. For
* example, don't do the following:
*
* copy( new BufferedInputStream( in ), new BufferedOutputStream( out ) );
*
* The rationale is as follows:
*
*
* Imagine that an InputStream's read() is a very expensive operation, which would usually suggest wrapping in a
* BufferedInputStream. The BufferedInputStream works by issuing infrequent
* {@link java.io.InputStream#read(byte[] b, int off, int len)} requests on the underlying InputStream, to fill an
* internal buffer, from which further read requests can inexpensively get their data (until the buffer
* runs out).
*
*
* However, the copy methods do the same thing, keeping an internal buffer, populated by
* {@link InputStream#read(byte[] b, int off, int len)} requests. Having two buffers (or three if the destination stream
* is also buffered) is pointless, and the unnecessary buffer management hurts performance slightly (about 3%, according
* to some simple experiments).
*
*
* @author Peter Donald
* @author Jeff Turner
*
* @since 4.0
*/
/*
* Behold, intrepid explorers; a map of this class: Method Input Output Dependency ------ ----- ------ ------- 1 copy
* InputStream OutputStream (primitive) 2 copy Reader Writer (primitive) 3 copy InputStream Writer 2 4 toString
* InputStream String 3 5 toByteArray InputStream byte[] 1 6 copy Reader OutputStream 2 7 toString Reader String 2 8
* toByteArray Reader byte[] 6 9 copy String OutputStream 2 10 copy String Writer (trivial) 11 toByteArray String byte[]
* 9 12 copy byte[] Writer 3 13 toString byte[] String 12 14 copy byte[] OutputStream (trivial) Note that only the first
* two methods shuffle bytes; the rest use these two, or (if possible) copy using native Java copy methods. As there are
* method variants to specify buffer size and encoding, each row may correspond to up to 4 methods.
*/
public final class IOUtil extends BaseIOUtil {
private static final int DEFAULT_BUFFER_SIZE = 1024 * 16;
/**
* Private constructor to prevent instantiation.
*/
private IOUtil() {}
///////////////////////////////////////////////////////////////
// Core copy methods
///////////////////////////////////////////////////////////////
/**
* Copy bytes from an InputStream to an OutputStream.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final InputStream input, final OutputStream output) throws IOException {
BaseIOUtil.copy(input, output);
}
/**
* Copy bytes from an InputStream to an OutputStream.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final InputStream input, final OutputStream output, final int bufferSize)
throws IOException {
final byte[] buffer = new byte[bufferSize];
int n = 0;
while (0 <= (n = input.read(buffer))) {
output.write(buffer, 0, n);
}
}
/**
* Copy chars from a Reader to a Writer.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final Reader input, final Writer output) throws IOException {
BaseIOUtil.copy(input, output);
}
/**
* Copy chars from a Reader to a Writer.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final Reader input, final Writer output, final int bufferSize) throws IOException {
final char[] buffer = new char[bufferSize];
int n = 0;
while (0 <= (n = input.read(buffer))) {
output.write(buffer, 0, n);
}
output.flush();
}
///////////////////////////////////////////////////////////////
// Derived copy methods
// InputStream -> *
///////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////
// InputStream -> Writer
/**
* Copy and convert bytes from an InputStream to chars on a Writer. The platform's default
* encoding is used for the byte-to-char conversion.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final InputStream input, final Writer output) throws IOException {
copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Copy and convert bytes from an InputStream to chars on a Writer. The platform's default
* encoding is used for the byte-to-char conversion.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final InputStream input, final Writer output, final int bufferSize) throws IOException {
final InputStreamReader in = new InputStreamReader(input);
copy(in, output, bufferSize);
}
/**
* Copy and convert bytes from an InputStream to chars on a Writer, using the specified
* encoding.
* @param input to convert
* @param output the result
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @throws IOException io issue
*/
public static void copy(final InputStream input, final Writer output, final String encoding) throws IOException {
final InputStreamReader in = new InputStreamReader(input, encoding);
copy(in, output);
}
/**
* Copy and convert bytes from an InputStream to chars on a Writer, using the specified
* encoding.
* @param input to convert
* @param output the result
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final InputStream input, final Writer output, final String encoding, final int bufferSize)
throws IOException {
final InputStreamReader in = new InputStreamReader(input, encoding);
copy(in, output, bufferSize);
}
///////////////////////////////////////////////////////////////
// InputStream -> String
/**
* @return Get the contents of an InputStream as a String. The platform's default encoding is used for the
* byte-to-char conversion.
* @param input to convert
* @throws IOException io issue
*/
public static String toString(final InputStream input) throws IOException {
return toString(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of an InputStream as a String. The platform's default encoding is used for the
* byte-to-char conversion.
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static String toString(final InputStream input, final int bufferSize) throws IOException {
final StringWriter sw = new StringWriter();
copy(input, sw, bufferSize);
return sw.toString();
}
/**
* @return Get the contents of an InputStream as a String.
* @param input to convert
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @throws IOException io issue
*/
public static String toString(final InputStream input, final String encoding) throws IOException {
return toString(input, encoding, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of an InputStream as a String.
* @param input to convert
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static String toString(final InputStream input, final String encoding, final int bufferSize)
throws IOException {
final StringWriter sw = new StringWriter();
copy(input, sw, encoding, bufferSize);
return sw.toString();
}
///////////////////////////////////////////////////////////////
// InputStream -> byte[]
/**
* @return Get the contents of an InputStream as a byte[].
* @param input to convert
* @throws IOException io issue
*/
public static byte[] toByteArray(final InputStream input) throws IOException {
return toByteArray(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of an InputStream as a byte[].
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static byte[] toByteArray(final InputStream input, final int bufferSize) throws IOException {
final ByteArrayOutputStream output = new ByteArrayOutputStream();
copy(input, output, bufferSize);
return output.toByteArray();
}
///////////////////////////////////////////////////////////////
// Derived copy methods
// Reader -> *
///////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////
// Reader -> OutputStream
/**
* Serialize chars from a Reader to bytes on an OutputStream, and flush the
* OutputStream.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final Reader input, final OutputStream output) throws IOException {
copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Serialize chars from a Reader to bytes on an OutputStream, and flush the
* OutputStream.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final Reader input, final OutputStream output, final int bufferSize) throws IOException {
final OutputStreamWriter out = new OutputStreamWriter(output);
copy(input, out, bufferSize);
// NOTE: Unless anyone is planning on rewriting OutputStreamWriter, we have to flush
// here.
out.flush();
}
///////////////////////////////////////////////////////////////
// Reader -> String
/**
* @return Get the contents of a Reader as a String.
* @param input to convert
* @throws IOException io issue
*/
public static String toString(final Reader input) throws IOException {
return toString(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of a Reader as a String.
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static String toString(final Reader input, final int bufferSize) throws IOException {
final StringWriter sw = new StringWriter();
copy(input, sw, bufferSize);
return sw.toString();
}
///////////////////////////////////////////////////////////////
// Reader -> byte[]
/**
* @return Get the contents of a Reader as a byte[].
* @param input to convert
* @throws IOException io issue
*/
public static byte[] toByteArray(final Reader input) throws IOException {
return toByteArray(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of a Reader as a byte[].
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static byte[] toByteArray(final Reader input, final int bufferSize) throws IOException {
ByteArrayOutputStream output = new ByteArrayOutputStream();
copy(input, output, bufferSize);
return output.toByteArray();
}
///////////////////////////////////////////////////////////////
// Derived copy methods
// String -> *
///////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////
// String -> OutputStream
/**
* Serialize chars from a String to bytes on an OutputStream, and flush the
* OutputStream.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final String input, final OutputStream output) throws IOException {
copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Serialize chars from a String to bytes on an OutputStream, and flush the
* OutputStream.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final String input, final OutputStream output, final int bufferSize) throws IOException {
final StringReader in = new StringReader(input);
final OutputStreamWriter out = new OutputStreamWriter(output);
copy(in, out, bufferSize);
// NOTE: Unless anyone is planning on rewriting OutputStreamWriter, we have to flush
// here.
out.flush();
}
///////////////////////////////////////////////////////////////
// String -> Writer
/**
* Copy chars from a String to a Writer.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final String input, final Writer output) throws IOException {
output.write(input);
}
/**
* Copy bytes from an InputStream to an OutputStream, with buffering. This is equivalent
* to passing a {@link java.io.BufferedInputStream} and {@link java.io.BufferedOutputStream} to
* {@link #copy(InputStream, OutputStream)}, and flushing the output stream afterwards. The streams are not closed
* after the copy.
* @param input to convert
* @param output the result
* @deprecated Buffering streams is actively harmful! See the class description as to why. Use
* {@link #copy(InputStream, OutputStream)} instead.
* @throws IOException io issue
*/
@Deprecated
public static void bufferedCopy(final InputStream input, final OutputStream output) throws IOException {
final BufferedInputStream in = new BufferedInputStream(input);
final BufferedOutputStream out = new BufferedOutputStream(output);
copy(in, out);
out.flush();
}
///////////////////////////////////////////////////////////////
// String -> byte[]
/**
* @return Get the contents of a String as a byte[].
* @param input to convert
* @throws IOException io issue
*/
public static byte[] toByteArray(final String input) throws IOException {
return toByteArray(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of a String as a byte[].
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static byte[] toByteArray(final String input, final int bufferSize) throws IOException {
ByteArrayOutputStream output = new ByteArrayOutputStream();
copy(input, output, bufferSize);
return output.toByteArray();
}
///////////////////////////////////////////////////////////////
// Derived copy methods
// byte[] -> *
///////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////
// byte[] -> Writer
/**
* Copy and convert bytes from a byte[] to chars on a Writer. The platform's default
* encoding is used for the byte-to-char conversion.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final byte[] input, final Writer output) throws IOException {
copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Copy and convert bytes from a byte[] to chars on a Writer. The platform's default
* encoding is used for the byte-to-char conversion.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final byte[] input, final Writer output, final int bufferSize) throws IOException {
final ByteArrayInputStream in = new ByteArrayInputStream(input);
copy(in, output, bufferSize);
}
/**
* Copy and convert bytes from a byte[] to chars on a Writer, using the specified
* encoding.
* @param input to convert
* @param output the result
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @throws IOException io issue
*/
public static void copy(final byte[] input, final Writer output, final String encoding) throws IOException {
final ByteArrayInputStream in = new ByteArrayInputStream(input);
copy(in, output, encoding);
}
/**
* Copy and convert bytes from a byte[] to chars on a Writer, using the specified
* encoding.
* @param input to convert
* @param output the result
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final byte[] input, final Writer output, final String encoding, final int bufferSize)
throws IOException {
final ByteArrayInputStream in = new ByteArrayInputStream(input);
copy(in, output, encoding, bufferSize);
}
///////////////////////////////////////////////////////////////
// byte[] -> String
/**
* @return Get the contents of a byte[] as a String. The platform's default encoding is used for the
* byte-to-char conversion.
* @param input to convert
* @throws IOException io issue
*/
public static String toString(final byte[] input) throws IOException {
return toString(input, DEFAULT_BUFFER_SIZE);
}
/**
* @return Get the contents of a byte[] as a String. The platform's default encoding is used for the
* byte-to-char conversion.
* @param input to convert
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static String toString(final byte[] input, final int bufferSize) throws IOException {
final StringWriter sw = new StringWriter();
copy(input, sw, bufferSize);
return sw.toString();
}
/**
* @return Get the contents of a byte[] as a String.
* @param input to convert
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @throws IOException io issue
*/
public static String toString(final byte[] input, final String encoding) throws IOException {
return toString(input, encoding, DEFAULT_BUFFER_SIZE);
}
/**
* @return the contents of a byte[] as a String.
* @param input to convert
* @param encoding The name of a supported character encoding. See the
* IANA Charset Registry for a list of valid
* encoding types.
* @param bufferSize Size of internal buffer to use.
*
* @throws IOException io issue
*/
public static String toString(final byte[] input, final String encoding, final int bufferSize) throws IOException {
final StringWriter sw = new StringWriter();
copy(input, sw, encoding, bufferSize);
return sw.toString();
}
///////////////////////////////////////////////////////////////
// byte[] -> OutputStream
/**
* Copy bytes from a byte[] to an OutputStream.
* @param input to convert
* @param output the result
* @throws IOException io issue
*/
public static void copy(final byte[] input, final OutputStream output) throws IOException {
copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Copy bytes from a byte[] to an OutputStream.
* @param input to convert
* @param output the result
* @param bufferSize Size of internal buffer to use.
* @throws IOException io issue
*/
public static void copy(final byte[] input, final OutputStream output, final int bufferSize) throws IOException {
output.write(input);
}
/**
* Compare the contents of two Streams to determine if they are equal or not.
*
* @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 IOException io issue
*/
public static boolean contentEquals(final InputStream input1, final InputStream input2) throws IOException {
final InputStream bufferedInput1 = new BufferedInputStream(input1);
final InputStream bufferedInput2 = new BufferedInputStream(input2);
int ch = bufferedInput1.read();
while (0 <= ch) {
final int ch2 = bufferedInput2.read();
if (ch != ch2) {
return false;
}
ch = bufferedInput1.read();
}
final int ch2 = bufferedInput2.read();
if (0 <= ch2) {
return false;
} else {
return true;
}
}
// ----------------------------------------------------------------------
// closeXXX()
// ----------------------------------------------------------------------
/**
* Closes the input stream. The input stream can be null and any IOException's will be swallowed.
*
* @param inputStream The stream to close.
* @deprecated use try-with-resources instead
*/
@Deprecated
public static void close(InputStream inputStream) {
if (inputStream == null) {
return;
}
try {
inputStream.close();
} catch (IOException ex) {
// ignore
}
}
/**
* Closes a channel. Channel can be null and any IOException's will be swallowed.
*
* @param channel The stream to close.
* @deprecated use try-with-resources instead
*/
@Deprecated
public static void close(Channel channel) {
if (channel == null) {
return;
}
try {
channel.close();
} catch (IOException ex) {
// ignore
}
}
/**
* Closes the output stream. The output stream can be null and any IOException's will be swallowed.
*
* @param outputStream The stream to close.
* @deprecated use try-with-resources instead
*/
@Deprecated
public static void close(OutputStream outputStream) {
if (outputStream == null) {
return;
}
try {
outputStream.close();
} catch (IOException ex) {
// ignore
}
}
/**
* Closes the reader. The reader can be null and any IOException's will be swallowed.
*
* @param reader The reader to close.
* @deprecated use try-with-resources instead
*/
@Deprecated
public static void close(Reader reader) {
if (reader == null) {
return;
}
try {
reader.close();
} catch (IOException ex) {
// ignore
}
}
/**
* Closes the writer. The writer can be null and any IOException's will be swallowed.
*
* @param writer The writer to close.
* @deprecated use try-with-resources instead
*/
@Deprecated
public static void close(Writer writer) {
if (writer == null) {
return;
}
try {
writer.close();
} catch (IOException ex) {
// ignore
}
}
}
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