Win a copy of Re-engineering Legacy Software this week in the Refactoring forum
or Docker in Action in the Cloud/Virtualization forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

Question about PipedOUtputStream / PipedInputStream

 
Anna Smalska
Greenhorn
Posts: 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello,
Using pipedoutputstream and pipedinputstream is the best way of converting outputstream into inputstream, but I have got question about a pice of code, does it make sense?



I am not sure if I can just return 'in' like this, and it will still work. Could somebody say if this is ok? Thank you.
 
James Sabre
Ranch Hand
Posts: 781
Java Netbeans IDE Ubuntu
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Of course it should be InputStream and not inputstream but the general approach is sound.
 
Rob Spoor
Sheriff
Pie
Posts: 20495
54
Chrome Eclipse IDE Java Windows
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Your code will probably suffer from the biggest flaw in PipedInputStream / PipedOutputStream. From the Javadoc of PipedInputStream:
A pipe is said to be broken if a thread that was providing data bytes to the connected piped output stream is no longer alive.

That means that you are going to need to keep that thread alive until you close the input stream.

I have one simple way of solving this, using a helper class:
The thread will now block until either interrupted or until the returned InputStream is closed, thereby keeping it alive long enough to not cause a broken pipe. The only way a broken pipe can now occur is either the wait being interrupted, or the reading (main?) thread ending before all output is processed.
 
Masa Saito
Greenhorn
Posts: 14
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Anna Smalska wrote:Hello,
Using pipedoutputstream and pipedinputstream is the best way of converting outputstream into inputstream,

What do you mean by this? What do you want to do?
I can almost guarantee you want to use ByteArrayOutputStream / ByteArrayInputStream. Pipes are rarely used.
 
Rob Spoor
Sheriff
Pie
Posts: 20495
54
Chrome Eclipse IDE Java Windows
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The disadvantage of using those is that you'll need to store the entire byte[] into memory.
 
Masa Saito
Greenhorn
Posts: 14
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Rob Prime wrote:The disadvantage of using those is that you'll need to store the entire byte[] into memory.

That is an interesting technique.
At the least, I'd test about buffering the streams and messing around with the buffer sizes.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic