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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 spark.utils;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
/**
* 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 Niall Pemberton
* @author Sandy McArthur
* @version $Id: IOUtils.java 481854 2006-12-03 18:30:07Z scolebourne $
*
* Code copied from apache commons io source. Changes made (mostly removal of methods) by Per Wendel.
*/
public final class IOUtils {
/**
* The system line separator string.
*/
public static final String LINE_SEPARATOR;
static {
// avoid security issues
StringWriter buf = new StringWriter(4); // NOSONAR
PrintWriter out = new PrintWriter(buf);
out.println();
LINE_SEPARATOR = buf.toString();
}
/**
* The default buffer size to use.
*/
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
private IOUtils() {
}
// 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 {
StringWriter sw = new StringWriter();
copy(input, sw);
return sw.toString();
}
/**
* Get the contents of an InputStream as a ByteArray
*
* This method buffers the input internally, so there is no need to use a
* BufferedInputStream.
*
* @param input
* the InputStream to read from
* @return the 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 os = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
for (int n = input.read(buf); n != -1; n = input.read(buf)) {
os.write(buf, 0, n);
}
return os.toByteArray();
}
/**
* 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); // NOSONAR
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
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @throws ArithmeticException if the character count is too large
* @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;
}
}