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Added new class per bug 13478, to read data from low performance input streams.

Patch submitted by Jens Gerhard - thanks.


git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@353030 13f79535-47bb-0310-9956-ffa450edef68
tags/REL_2_0_PRE1
Avik Sengupta 21 years ago
parent
commit
a50c693053
1 changed files with 100 additions and 0 deletions
  1. 100
    0
      src/java/org/apache/poi/util/BlockingInputStream.java

+ 100
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src/java/org/apache/poi/util/BlockingInputStream.java View File

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package org.apache.poi.util;

import java.io.InputStream;
import java.io.IOException;

/**
* Implementation of a BlockingInputStream to provide data to
* RawDataBlock that expects data in 512 byte chunks. Useful to read
* data from slow (ie, non FileInputStream) sources, for example when
* reading an OLE2 Document over a network.
*
* Possible extentions: add a timeout. Curently a call to read(byte[]) on this
* class is blocking, so use at your own peril if your underlying stream blocks.
*
* @author Jens Gerhard
* @author aviks - documentation cleanups.
*/
public class BlockingInputStream
extends InputStream
{
protected InputStream is;

public BlockingInputStream(InputStream is)
{
this.is = is;
}

public int available()
throws IOException
{
return is.available();
}

public void close()
throws IOException
{
is.close();
}

public void mark(int readLimit)
{
is.mark(readLimit);
}

public boolean markSupported()
{
return is.markSupported();
}

public int read()
throws IOException
{
return is.read();
}
/**
* We had to revert to byte per byte reading to keep
* with slow network connections on one hand, without
* missing the end-of-file.
* This is the only method that does its own thing in this class
* everything else is delegated to aggregated stream.
* THIS IS A BLOCKING BLOCK READ!!!
*/
public int read(byte[] bf)
throws IOException
{
int i = 0;
int b = 4611;
while ( i < bf.length )
{
b = is.read();
if ( b == -1 )
break;
bf[i++] = (byte) b;
}
if ( i == 0 && b == -1 )
return -1;
return i;
}

public int read(byte[] bf, int s, int l)
throws IOException
{
return is.read(bf, s, l);
}

public void reset()
throws IOException
{
is.reset();
}

public long skip(long n)
throws IOException
{
return is.skip(n);
}
}


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