Constructor Detail

• POIFSFileSystem

  public POIFSFileSystem()

  Constructor, intended for writing

• POIFSFileSystem

  public POIFSFileSystem(java.io.InputStream stream)
                  throws java.io.IOException

  Create a POIFSFileSystem from an InputStream. Normally the stream is read until EOF. The stream is always closed.

  Some streams are usable after reaching EOF (typically those that return true for markSupported()). In the unlikely case that the caller has such a stream and needs to use it after this constructor completes, a work around is to wrap the stream in order to trap the close() call. A convenience method ( createNonClosingInputStream()) has been provided for this purpose:

   InputStream wrappedStream = POIFSFileSystem.createNonClosingInputStream(is);
   HSSFWorkbook wb = new HSSFWorkbook(wrappedStream);
   is.reset();
   doSomethingElse(is);
   

  Note also the special case of ByteArrayInputStream for which the close() method does nothing.

   ByteArrayInputStream bais = ...
   HSSFWorkbook wb = new HSSFWorkbook(bais); // calls bais.close() !
   bais.reset(); // no problem
   doSomethingElse(bais);
   

  Parameters:

  stream - the InputStream from which to read the data

  Throws:

  java.io.IOException - on errors reading, or on invalid data

• POIFSFileSystem

  public POIFSFileSystem(java.io.File file,
                 boolean readOnly)
                  throws java.io.IOException

  Creates a POIFSFileSystem from a File. This uses less memory than creating from an InputStream.

  Note that with this constructor, you will need to call NPOIFSFileSystem.close() when you're done to have the underlying file closed, as the file is kept open during normal operation to read the data out.

  Parameters:

  readOnly - whether the POIFileSystem will only be used in read-only mode

  file - the File from which to read the data

  Throws:

  java.io.IOException - on errors reading, or on invalid data

• POIFSFileSystem

  public POIFSFileSystem(java.io.File file)
                  throws java.io.IOException

  Creates a POIFSFileSystem from a File. This uses less memory than creating from an InputStream. The File will be opened read-only

  Note that with this constructor, you will need to call NPOIFSFileSystem.close() when you're done to have the underlying file closed, as the file is kept open during normal operation to read the data out.

  Parameters:

  file - the File from which to read the data

  Throws:

  java.io.IOException - on errors reading, or on invalid data

Method Detail

• createNonClosingInputStream

  public static java.io.InputStream createNonClosingInputStream(java.io.InputStream is)

  Convenience method for clients that want to avoid the auto-close behaviour of the constructor.

• hasPOIFSHeader

  public static boolean hasPOIFSHeader(java.io.InputStream inp)
                                throws java.io.IOException

  Checks that the supplied InputStream (which MUST support mark and reset, or be a PushbackInputStream) has a POIFS (OLE2) header at the start of it. If your InputStream does not support mark / reset, then wrap it in a PushBackInputStream, then be sure to always use that, and not the original!

  Parameters:

  inp - An InputStream which supports either mark/reset, or is a PushbackInputStream

  Throws:

  java.io.IOException

• hasPOIFSHeader

  public static boolean hasPOIFSHeader(byte[] header8Bytes)

  Checks if the supplied first 8 bytes of a stream / file has a POIFS (OLE2) header.

• create

  public static POIFSFileSystem create(java.io.File file)
                                throws java.io.IOException

  Creates a new POIFSFileSystem in a new File. Use POIFSFileSystem(File) to open an existing File, this should only be used to create a new empty filesystem.

  Parameters:

  file - The file to create and open

  Returns:

  The created and opened POIFSFileSystem

  Throws:

  java.io.IOException

• main

  public static void main(java.lang.String[] args)
                   throws java.io.IOException

  read in a file and write it back out again

  Parameters:

  args - names of the files; arg[ 0 ] is the input file, arg[ 1 ] is the output file

  Throws:

  java.io.IOException