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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.feilong.lib.io;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.Collection;
import com.feilong.lib.io.output.StringBuilderWriter;
/**
* General IO stream manipulation utilities.
*
* This class provides static utility methods for input/output operations.
*
* - [Deprecated] 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.
*
* The various copy methods all delegate the actual copying to one of the following methods:
*
* - {@link #copyLarge(InputStream, OutputStream, byte[])}
* - {@link #copyLarge(Reader, Writer, char[])}
*
* For example, {@link #copy(InputStream, OutputStream)} calls {@link #copyLarge(InputStream, OutputStream)}
* which calls {@link #copy(InputStream, OutputStream, int)} which creates the buffer and calls
* {@link #copyLarge(InputStream, OutputStream, byte[])}.
*
* Applications can re-use buffers by using the underlying methods directly.
* This may improve performance for applications that need to do a lot of copying.
*
* 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.
*
*/
public class IOUtils{
// NOTE: This class is focused on InputStream, OutputStream, Reader and
// Writer. Each method should take at least one of these as a parameter,
// or return one of them.
/**
* Represents the end-of-file (or stream).
*
* @since 2.5 (made public)
*/
public static final int EOF = -1;
/**
* The Unix directory separator character.
*/
public static final char DIR_SEPARATOR_UNIX = '/';
/**
* 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
try (final StringBuilderWriter buf = new StringBuilderWriter(4); final PrintWriter out = new PrintWriter(buf)){
out.println();
LINE_SEPARATOR = buf.toString();
}
}
/**
* The default buffer size ({@value}) to use for
* {@link #copyLarge(InputStream, OutputStream)}
* and
* {@link #copyLarge(Reader, Writer)}
*/
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
//-----------------------------------------------------------------------
/**
* Gets 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{
try (final ByteArrayOutputStream output = new ByteArrayOutputStream()){
copy(input, output);
return output.toByteArray();
}
}
/**
* Copies 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 1.1
*/
public static int copy(final InputStream input,final OutputStream output) throws IOException{
final long count = copyLarge(input, output);
if (count > Integer.MAX_VALUE){
return -1;
}
return (int) count;
}
/**
* Copies 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.
*
* The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
*
* @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 1.3
*/
public static long copyLarge(final InputStream input,final OutputStream output) throws IOException{
return copy(input, output, DEFAULT_BUFFER_SIZE);
}
/**
* Copies bytes from an InputStream to an OutputStream using an internal buffer of the
* given size.
*
* 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
* @param bufferSize
* the bufferSize used to copy from the input to the output
* @return the number of bytes copied
* @throws NullPointerException
* if the input or output is null
* @throws IOException
* if an I/O error occurs
* @since 2.5
*/
public static long copy(final InputStream input,final OutputStream output,final int bufferSize) throws IOException{
return copyLarge(input, output, new byte[bufferSize]);
}
/**
* Copies bytes from a large (over 2GB) InputStream to an
* OutputStream.
*
* This method uses the provided buffer, so there is no need to use a
* BufferedInputStream.
*
*
* @param input
* the InputStream to read from
* @param output
* the OutputStream to write to
* @param buffer
* the buffer to use for the copy
* @return the number of bytes copied
* @throws NullPointerException
* if the input or output is null
* @throws IOException
* if an I/O error occurs
* @since 2.2
*/
public static long copyLarge(final InputStream input,final OutputStream output,final byte[] buffer) throws IOException{
long count = 0;
int n;
while (EOF != (n = input.read(buffer))){
output.write(buffer, 0, n);
count += n;
}
return count;
}
/**
* Returns the given reader if it is a {@link BufferedReader}, otherwise creates a BufferedReader from the given
* reader.
*
* @param reader
* the reader to wrap or return (not null)
* @return the given reader or a new {@link BufferedReader} for the given reader
* @throws NullPointerException
* if the input parameter is null
* @since 2.2
*/
public static BufferedReader toBufferedReader(final Reader reader){
return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader);
}
// read toByteArray
//-----------------------------------------------------------------------
/**
* Gets 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 2.1
*/
public static byte[] toByteArray(final InputStream input,final 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];
}
final byte[] data = new byte[size];
int offset = 0;
int read;
while (offset < size && (read = input.read(data, offset, size - offset)) != EOF){
offset += read;
}
if (offset != size){
throw new IOException("Unexpected read size. current: " + offset + ", expected: " + size);
}
return data;
}
// read toString
/**
* Gets 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{
try (final StringBuilderWriter sw = new StringBuilderWriter()){
copy(input, sw);
return sw.toString();
}
}
/**
* Copies 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 1.1
*/
public static int copy(final Reader input,final Writer output) throws IOException{
final long count = copyLarge(input, output);
if (count > Integer.MAX_VALUE){
return -1;
}
return (int) count;
}
/**
* Copies 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.
*
* The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
*
* @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 1.3
*/
public static long copyLarge(final Reader input,final Writer output) throws IOException{
return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
}
/**
* Copies chars from a large (over 2GB) Reader to a Writer.
*
* This method uses the provided buffer, so there is no need to use a
* BufferedReader.
*
*
* @param input
* the Reader to read from
* @param output
* the Writer to write to
* @param buffer
* the buffer to be used for the copy
* @return the number of characters copied
* @throws NullPointerException
* if the input or output is null
* @throws IOException
* if an I/O error occurs
* @since 2.2
*/
public static long copyLarge(final Reader input,final Writer output,final char[] buffer) throws IOException{
long count = 0;
int n;
while (EOF != (n = input.read(buffer))){
output.write(buffer, 0, n);
count += n;
}
return count;
}
// readLines
//-----------------------------------------------------------------------
/**
* Writes bytes from a byte[] to chars on a Writer
* using the specified character encoding.
*
* 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 2.3
*/
public static void write(final byte[] data,final Writer output,final Charset encoding) throws IOException{
if (data != null){
output.write(new String(data, Charsets.toCharset(encoding)));
}
}
// write String
//-----------------------------------------------------------------------
/**
* Writes chars from a String to bytes on an
* OutputStream using the specified character encoding.
*
* 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 2.3
*/
public static void write(final String data,final OutputStream output,final Charset encoding) throws IOException{
if (data != null){
output.write(data.getBytes(Charsets.toCharset(encoding)));
}
}
// writeLines
//-----------------------------------------------------------------------
/**
* 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.
*
* @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 2.3
*/
public static void writeLines(final Collection lines,String lineEnding,final OutputStream output,final Charset encoding)
throws IOException{
if (lines == null){
return;
}
if (lineEnding == null){
lineEnding = LINE_SEPARATOR;
}
final Charset cs = Charsets.toCharset(encoding);
for (final Object line : lines){
if (line != null){
output.write(line.toString().getBytes(cs));
}
output.write(lineEnding.getBytes(cs));
}
}
/**
* 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
* @throws java.nio.charset.UnsupportedCharsetException
* thrown instead of {@link java.io
* .UnsupportedEncodingException} in version 2.2 if the
* encoding is not supported.
* @since 1.1
*/
public static void writeLines(final Collection lines,final String lineEnding,final OutputStream output,final String encoding)
throws IOException{
writeLines(lines, lineEnding, output, Charsets.toCharset(encoding));
}
// copy from InputStream
}