alex.mojaki.s3upload

Class MultiPartOutputStream

java.lang.Object

java.io.OutputStream

alex.mojaki.s3upload.MultiPartOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class MultiPartOutputStream
extends OutputStream

An OutputStream which packages data written to it into discrete StreamParts which can be obtained in a separate thread via iteration and uploaded to S3.

A single MultiPartOutputStream is allocated a range of part numbers it can assign to the StreamParts it produces, which is determined at construction.

Creating a StreamPart is triggered when checkSize() is called and the stream holds enough data, so be sure to call this regularly when writing data. It's also essential to call close() when finished so that it can create the final StreamPart and consumers can finish.

Field Summary

Fields

Modifier and Type	Field and Description
static int	S3_MIN_PART_SIZE

Constructor Summary

Constructors

Constructor and Description
MultiPartOutputStream(int partNumberStart, int partNumberEnd, int partSize, BlockingQueue<alex.mojaki.s3upload.StreamPart> queue) Creates a new stream that will produce parts of the given size with part numbers in the given range.

Method Summary

Modifier and Type	Method and Description
void	checkSize() Checks if the stream currently contains enough data to create a new part.
void	close() Packages any remaining data into a StreamPart and signals to the StreamTransferManager that there are no more parts afterwards.
String	toString()
void	write(byte[] b)
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.io.OutputStream

flush

Methods inherited from class java.lang.Object

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

Field Detail

S3_MIN_PART_SIZE

public static final int S3_MIN_PART_SIZE

See Also:

Constant Field Values

Constructor Detail

MultiPartOutputStream

public MultiPartOutputStream(int partNumberStart,
                             int partNumberEnd,
                             int partSize,
                             BlockingQueue<alex.mojaki.s3upload.StreamPart> queue)

Creates a new stream that will produce parts of the given size with part numbers in the given range.

Parameters:

partNumberStart - the part number of the first part the stream will produce. Minimum 1.

partNumberEnd - 1 more than the last part number that the parts are allowed to have. Maximum 10 001.

partSize - the minimum size in bytes of parts to be produced.

queue - where stream parts are put on production.

Method Detail

checkSize

public void checkSize()
               throws InterruptedException

Checks if the stream currently contains enough data to create a new part.

Internally this puts the part on a queue, which if full will cause this method to block and potentially throw an InterruptedException, in which case retrying is acceptable.

Throws:

InterruptedException

write

public void write(int b)

Specified by:

write in class OutputStream

write

public void write(byte[] b,
                  int off,
                  int len)

Overrides:

write in class OutputStream

write

public void write(byte[] b)

Overrides:

write in class OutputStream

close

public void close()

Packages any remaining data into a StreamPart and signals to the StreamTransferManager that there are no more parts afterwards. You cannot write to the stream after it has been closed.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

toString

public String toString()

Overrides:

toString in class Object