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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.
*/
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/** Utility class for working with streams.
*/
public final class Streams {
/**
* Default buffer size for use in
* {@link #copy(InputStream, OutputStream, boolean)}.
*/
private static final int DEFAULT_BUFFER_SIZE = 8192;
/**
* Copies the contents of the given {@link InputStream}
* to the given {@link OutputStream}. Shortcut for
* <pre>
* copy(pInputStream, pOutputStream, new byte[8192]);
* </pre>
* @param pInputStream The input stream, which is being read.
* It is guaranteed, that {@link InputStream#close()} is called
* on the stream.
* @param pOutputStream The output stream, to which data should
* be written. May be null, in which case the input streams
* contents are simply discarded.
* @param pClose True guarantees, that {@link OutputStream#close()}
* is called on the stream. False indicates, that only
* {@link OutputStream#flush()} should be called finally.
*
* @return Number of bytes, which have been copied.
* @throws IOException An I/O error occurred.
*/
public static long copy(InputStream pInputStream,
OutputStream pOutputStream, boolean pClose)
throws IOException {
return copy(pInputStream, pOutputStream, pClose,
new byte[DEFAULT_BUFFER_SIZE]);
}
/**
* Copies the contents of the given {@link InputStream}
* to the given {@link OutputStream}.
* @param pIn The input stream, which is being read.
* It is guaranteed, that {@link InputStream#close()} is called
* on the stream.
* @param pOut The output stream, to which data should
* be written. May be null, in which case the input streams
* contents are simply discarded.
* @param pClose True guarantees, that {@link OutputStream#close()}
* is called on the stream. False indicates, that only
* {@link OutputStream#flush()} should be called finally.
* @param pBuffer Temporary buffer, which is to be used for
* copying data.
* @return Number of bytes, which have been copied.
* @throws IOException An I/O error occurred.
*/
public static long copy(InputStream pIn,
OutputStream pOut, boolean pClose,
byte[] pBuffer)
throws IOException {
OutputStream out = pOut;
InputStream in = pIn;
try {
long total = 0;
for (;;) {
int res = in.read(pBuffer);
if (res == -1) {
break;
}
if (res > 0) {
total += res;
if (out != null) {
out.write(pBuffer, 0, res);
}
}
}
if (out != null) {
if (pClose) {
out.close();
} else {
out.flush();
}
out = null;
}
in.close();
in = null;
return total;
} finally {
if (in != null) {
try {
in.close();
} catch (Throwable t) {
/* Ignore me */
}
}
if (pClose && out != null) {
try {
out.close();
} catch (Throwable t) {
/* Ignore me */
}
}
}
}
/**
* This convenience method allows to read a
* {@link org.apache.commons.fileupload.FileItemStream}'s
* content into a string. The platform's default character encoding
* is used for converting bytes into characters.
* @param pStream The input stream to read.
* @see #asString(InputStream, String)
* @return The streams contents, as a string.
* @throws IOException An I/O error occurred.
*/
public static String asString(InputStream pStream) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
copy(pStream, baos, true);
return baos.toString();
}
/**
* This convenience method allows to read a
* {@link org.apache.commons.fileupload.FileItemStream}'s
* content into a string, using the given character encoding.
* @param pStream The input stream to read.
* @param pEncoding The character encoding, typically "UTF-8".
* @see #asString(InputStream)
* @return The streams contents, as a string.
* @throws IOException An I/O error occurred.
*/
public static String asString(InputStream pStream, String pEncoding)
throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
copy(pStream, baos, true);
return baos.toString(pEncoding);
}
}
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