Is InputStream.close() a blocking call in java?

Question

I read from an input stream and in my finally block try to close it by calling in.close(); However the execution of main gets blocked . What is the way out ?

On suggestion , the code I used is ,

if (!processed) {
                System.out.println("in processed");
                byte[] contents = new byte[(int) fileSplit.getLength()];
                Path file = fileSplit.getPath();
                FileSystem fs = file.getFileSystem(conf);
                FSDataInputStream in = null;
                try {
                    in = fs.open(file);
                    IOUtils.readFully(in, contents, 0, contents.length);

                    value.set(contents, 0, contents.length);
                } finally {
                    System.out.println("before close stream");
                    IOUtils.closeStream(in);
                }
                processed = true;
                return true;
            }
            System.out.println("out of processed");
            return false;
        }

similar post ..http://stackoverflow.com/questions/646940/why-does-javas-inputstream-close-block — stinepike, Dec 10 '12 at 06:33
You aren't even using `InputStream` here, and no, `InputStream.close()` does not block. — Brian Roach, Dec 10 '12 at 06:50
@BrianRoach : FSDataInputStream is a type of Input Stream fro Hadoop . — RadAl, Dec 10 '12 at 06:56
Sorry - I meant to say "You're not even using `InputStream.close()` here." You're using an apache library that hides exceptions from you to call it. — Brian Roach, Dec 10 '12 at 06:59
Sorry for the ridiculous question. I cannot find FileSystem.open() method in the docs http://docs.oracle.com/javase/7/docs/api/java/nio/file/FileSystems.html#getFileSystem(java.net.URI) — Bhavik Shah, Dec 10 '12 at 07:22
All operations on all Java streams are blocking, as it says in the Javadoc. — user207421, Dec 10 '12 at 08:49

Evgeniy Dorofeev · Accepted Answer · 2012-12-10T09:40:29.350

-1

java.io.InputStream.close is not blocking, at least API never says that. Compare InputStream.read

 Reads the next byte of data from the input stream. The value byte is
 returned as an <code>int</code> in the range <code>0</code> to
 <code>255</code>. If no byte is available because the end of the stream
 has been reached, the value <code>-1</code> is returned. This method
 blocks until input data is available, the end of the stream is detected,
 or an exception is thrown.

and InputStream.close

  Closes this file input stream and releases any system resources
  associated with the stream.

As for solving your problem I would suggest to use Java 7 Files.readAllBytes and forget about your puzzle.

edited Dec 10 '12 at 09:40

answered Dec 10 '12 at 06:35

Evgeniy Dorofeev

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Cant use Files.readAllBytes because this is a part of an architecture that needs read to be done by defining start and end positions and into a buffer . – RadAl Dec 10 '12 at 06:49
*All* I/O on streams is blocking. – user207421 Dec 10 '12 at 08:51

Is InputStream.close() a blocking call in java?

1 Answers1