cvs commit: jakarta-poi/src/java/org/apache/poi/util BlockingInputStream.java

[av...@apache.org]

avik        2003/03/18 10:58:44

  Added:       src/java/org/apache/poi/util BlockingInputStream.java
  Log:
  Added new class per bug 13478, to read data from low performance input streams.
  Patch submitted by Jens Gerhard - thanks.
  
  Revision  Changes    Path
  1.1                  jakarta-poi/src/java/org/apache/poi/util/BlockingInputStream.java
  
  Index: BlockingInputStream.java
  ===================================================================
  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);
        }
  }