org.apache.druid.java.util.common.StreamUtils Maven / Gradle / Ivy
/*
* 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 org.apache.druid.java.util.common;
import com.google.common.base.Predicate;
import com.google.common.base.Throwables;
import com.google.common.io.ByteSink;
import com.google.common.io.ByteSource;
import com.google.common.io.ByteStreams;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
*/
public class StreamUtils
{
/**
* Copy from an input stream to a file (and buffer it) and close the input stream.
*
* It is highly recommended to use FileUtils.retryCopy whenever possible, and not use a raw `InputStream`
*
* @param is The input stream to copy bytes from. `is` is closed regardless of the copy result.
* @param file The file to copy bytes to. Any parent directories are automatically created.
*
* @return The count of bytes written to the file
*
* @throws IOException
*/
public static long copyToFileAndClose(InputStream is, File file) throws IOException
{
file.getParentFile().mkdirs();
try (OutputStream os = new BufferedOutputStream(new FileOutputStream(file))) {
final long result = ByteStreams.copy(is, os);
// Workarround for http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/759aa847dcaf
os.flush();
return result;
}
finally {
is.close();
}
}
/**
* Copy from `is` to `os` and close the streams regardless of the result.
*
* @param is The `InputStream` to copy results from. It is closed
* @param os The `OutputStream` to copy results to. It is closed
*
* @return The count of bytes written to `os`
*
* @throws IOException
*/
public static long copyAndClose(InputStream is, OutputStream os) throws IOException
{
try {
final long retval = ByteStreams.copy(is, os);
// Workarround for http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/759aa847dcaf
os.flush();
return retval;
}
finally {
is.close();
os.close();
}
}
/**
* Retry copy attempts from input stream to output stream. Does *not* check to make sure data was intact during the transfer
*
* @param byteSource Supplier for input streams to copy from. The stream is closed on every retry.
* @param byteSink Supplier for output streams. The stream is closed on every retry.
* @param shouldRetry Predicate to determine if the throwable is recoverable for a retry
* @param maxAttempts Maximum number of retries before failing
*/
public static long retryCopy(
final ByteSource byteSource,
final ByteSink byteSink,
final Predicate shouldRetry,
final int maxAttempts
)
{
try {
return RetryUtils.retry(
() -> {
try (InputStream inputStream = byteSource.openStream()) {
try (OutputStream outputStream = byteSink.openStream()) {
final long retval = ByteStreams.copy(inputStream, outputStream);
// Workarround for http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/759aa847dcaf
outputStream.flush();
return retval;
}
}
},
shouldRetry,
maxAttempts
);
}
catch (Exception e) {
throw Throwables.propagate(e);
}
}
}