/**
* This file is part of the JCROM project.
* Copyright (C) 2008-2014 - All rights reserved.
* Authors: Olafur Gauti Gudmundsson, Nicolas Dos Santos
*
* Licensed 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.jcrom.util.io;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
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.StringWriter;
import java.io.Writer;
/**
* General IO stream manipulation utilities.
*
* <p>This class provides static utility methods for input/output operations.</p>
*/
public final class IOUtils {
/**
* 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
StringWriter buf = new StringWriter(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;
private IOUtils() {
}
/**
* Unconditionally close an <code>InputStream</code>.
* <p>
* Equivalent to {@link InputStream#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
* <p>
* Example code:
* <pre>
* 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);
* }
* </pre>
*
* @param input the InputStream to close, may be null or already closed
*/
public static void closeQuietly(InputStream input) {
closeQuietly((Closeable) input);
}
/**
* Unconditionally close a <code>Closeable</code>.
* <p>
* Equivalent to {@link Closeable#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
* <p>
* Example code:
* <pre>
* Closeable closeable = null;
* try {
* closeable = new FileReader("foo.txt");
* // process closeable
* closeable.close();
* } catch (Exception e) {
* // error handling
* } finally {
* IOUtils.closeQuietly(closeable);
* }
* </pre>
*
* @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
}
}
/**
* Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> 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 <code>InputStream</code> as a <code>byte[]</code>.
* Use this method instead of <code>toByteArray(InputStream)</code>
* when <code>InputStream</code> size is known.
* <b>NOTE:</b> 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 <code>InputStream</code> to read from
* @param size the size of <code>InputStream</code>
* @return the requested byte array
* @throws IOException if an I/O error occurs or <code>InputStream</code> 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 <code>InputStream</code> as a <code>byte[]</code>.
* Use this method instead of <code>toByteArray(InputStream)</code>
* when <code>InputStream</code> size is known
* @param input the <code>InputStream</code> to read from
* @param size the size of <code>InputStream</code>
* @return the requested byte array
* @throws IOException if an I/O error occurs or <code>InputStream</code> 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 an <code>InputStream</code> as a String
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from
* @param encoding the encoding to use, null means platform default
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
*/
public static String toString(InputStream input, String encoding) throws IOException {
StringWriter sw = new StringWriter();
copy(input, sw, encoding);
return sw.toString();
}
/**
* Copy bytes from an <code>InputStream</code> to an
* <code>OutputStream</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* Large streams (over 2GB) will return a bytes copied value of
* <code>-1</code> after the copy has completed since the correct
* number of bytes cannot be returned as an int. For large streams
* use the <code>copyLarge(InputStream, OutputStream)</code> method.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>OutputStream</code> 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) <code>InputStream</code> to an
* <code>OutputStream</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>OutputStream</code> 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 <code>InputStream</code> to chars on a
* <code>Writer</code> using the default character encoding of the platform.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* This method uses {@link InputStreamReader}.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>Writer</code> 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 <code>InputStream</code> to chars on a
* <code>Writer</code> using the specified character encoding.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link InputStreamReader}.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>Writer</code> 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 chars from a <code>Reader</code> to a <code>Writer</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
* <p>
* Large streams (over 2GB) will return a chars copied value of
* <code>-1</code> after the copy has completed since the correct
* number of chars cannot be returned as an int. For large streams
* use the <code>copyLarge(Reader, Writer)</code> method.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>Writer</code> 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) <code>Reader</code> to a <code>Writer</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>Writer</code> 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 <code>Reader</code> to bytes on an
* <code>OutputStream</code> using the default character encoding of the
* platform, and calling flush.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
* <p>
* Due to the implementation of OutputStreamWriter, this method performs a
* flush.
* <p>
* This method uses {@link OutputStreamWriter}.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>OutputStream</code> 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();
}
}