com.qcloud.cos.utils.IOUtils Maven / Gradle / Ivy
/*
* Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.
* According to cos feature, we modify some class，comment, field name, etc.
*/
package com.qcloud.cos.utils;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.qcloud.cos.internal.Releasable;
/**
* Utilities for IO operations.
*/
public enum IOUtils {
;
private static final int BUFFER_SIZE = 1024 * 4;
private static final Logger defaultLog = LoggerFactory.getLogger(IOUtils.class);
/**
* Reads and returns the rest of the given input stream as a byte array. Caller is responsible
* for closing the given input stream.
*/
public static byte[] toByteArray(InputStream is) throws IOException {
ByteArrayOutputStream output = new ByteArrayOutputStream();
try {
byte[] b = new byte[BUFFER_SIZE];
int n = 0;
while ((n = is.read(b)) != -1) {
output.write(b, 0, n);
}
return output.toByteArray();
} finally {
output.close();
}
}
/**
* Reads and returns the rest of the given input stream as a string. Caller is responsible for
* closing the given input stream.
*/
public static String toString(InputStream is) throws IOException {
return new String(toByteArray(is), StringUtils.UTF8);
}
/**
* Closes the given Closeable quietly.
*
* @param is the given closeable
* @param log logger used to log any failure should the close fail
*/
public static void closeQuietly(Closeable is, Logger log) {
if (is != null) {
try {
is.close();
} catch (IOException ex) {
Logger logger = log == null ? defaultLog : log;
if (logger.isDebugEnabled())
logger.debug("Ignore failure in closing the Closeable", ex);
}
}
}
/**
* Releases the given {@link Closeable} especially if it was an instance of {@link Releasable}.
*
* For example, the creation of a ResettableInputStream would entail physically
* opening a file. If the opened file is meant to be closed only (in a finally block) by the
* very same code block that created it, then it is necessary that the release method must not
* be called while the execution is made in other stack frames.
*
* In such case, as other stack frames may inadvertently or indirectly call the close method of
* the stream, the creator of the stream would need to explicitly disable the accidental closing
* via ResettableInputStream#disableClose(), so that the release method becomes the
* only way to truly close the opened file.
*/
public static void release(Closeable is, Logger log) {
closeQuietly(is, log);
if (is instanceof Releasable) {
Releasable r = (Releasable) is;
r.release();
}
}
/**
* Copies all bytes from the given input stream to the given output stream. Caller is
* responsible for closing the streams.
*
* @throws IOException if there is any IO exception during read or write.
*/
public static long copy(InputStream in, OutputStream out) throws IOException {
byte[] buf = new byte[BUFFER_SIZE];
long count = 0;
int n = 0;
while ((n = in.read(buf)) > -1) {
out.write(buf, 0, n);
count += n;
}
return count;
}
/**
* Read all remaining data in the stream.
*
* @param in InputStream to read.
*/
public static void drainInputStream(InputStream in) {
try {
while (in.read() != -1) {
// Do nothing.
}
} catch (IOException ignored) {
// Stream may be self closed by HTTP client so we ignore any failures.
}
}
}