com.metamx.common

Class StreamUtils

java.lang.Object

com.metamx.common.StreamUtils

public class StreamUtils
extends Object

Constructor Summary

Constructors

Constructor and Description
StreamUtils()

Method Summary

Methods

Modifier and Type	Method and Description
static long	copyAndClose(InputStream is, OutputStream os) Copy from `is` to `os` and close the streams regardless of the result.
static long	copyToFileAndClose(InputStream is, File file) Copy from an input stream to a file (and buffer it) and close the input stream.
static long	copyToFileAndClose(InputStream is, File file, long timeout) Copy bytes from `is` to `file` but timeout if the copy takes too long.
static long	copyWithTimeout(InputStream is, OutputStream os, long timeout) Copy from the input stream to the output stream and tries to exit if the copy exceeds the timeout.
static long	retryCopy(com.google.common.io.ByteSource byteSource, com.google.common.io.ByteSink byteSink, com.google.common.base.Predicate<Throwable> shouldRetry, int maxAttempts) Retry copy attempts from input stream to output stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StreamUtils

public StreamUtils()

Method Detail

copyToFileAndClose

public static long copyToFileAndClose(InputStream is,
                      File file)
                               throws IOException

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`

Parameters:

is - The input stream to copy bytes from. `is` is closed regardless of the copy result.

file - The file to copy bytes to. Any parent directories are automatically created.

Returns:

The count of bytes written to the file

Throws:

IOException

copyToFileAndClose

public static long copyToFileAndClose(InputStream is,
                      File file,
                      long timeout)
                               throws IOException,
                                      TimeoutException

Copy bytes from `is` to `file` but timeout if the copy takes too long. The timeout is best effort and not guaranteed. Specifically, `is.read` will not be interrupted.

Parameters:

is - The `InputStream` to copy bytes from. It is closed regardless of copy results.

file - The `File` to copy bytes to

timeout - The timeout (in ms) of the copy.

Returns:

The size of bytes written to `file`

Throws:

IOException

TimeoutException - If `timeout` is exceeded

copyAndClose

public static long copyAndClose(InputStream is,
                OutputStream os)
                         throws IOException

Copy from `is` to `os` and close the streams regardless of the result.

Parameters:

is - The `InputStream` to copy results from. It is closed

os - The `OutputStream` to copy results to. It is closed

Returns:

The count of bytes written to `os`

Throws:

IOException

copyWithTimeout

public static long copyWithTimeout(InputStream is,
                   OutputStream os,
                   long timeout)
                            throws IOException,
                                   TimeoutException

Copy from the input stream to the output stream and tries to exit if the copy exceeds the timeout. The timeout is best effort. Specifically, `is.read` will not be interrupted.

Parameters:

is - The input stream to read bytes from.

os - The output stream to write bytes to.

timeout - The timeout (in ms) for the copy operation

Returns:

The total size of bytes written to `os`

Throws:

IOException

TimeoutException - If `tiemout` is exceeded

retryCopy

public static long retryCopy(com.google.common.io.ByteSource byteSource,
             com.google.common.io.ByteSink byteSink,
             com.google.common.base.Predicate<Throwable> shouldRetry,
             int maxAttempts)

Retry copy attempts from input stream to output stream. Does *not* check to make sure data was intact during the transfer

Parameters:

byteSource - Supplier for input streams to copy from. The stream is closed on every retry.

byteSink - Supplier for output streams. The stream is closed on every retry.

shouldRetry - Predicate to determine if the throwable is recoverable for a retry

maxAttempts - Maximum number of retries before failing