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
This commit is contained in:
Avik Sengupta 2003-03-18 18:58:43 +00:00
parent fb495e66a7
commit 3048751bca

View File

@ -0,0 +1,100 @@
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);
}
}