POIFSFileSystem (Keikai Spreadsheet Build 5.0.0 API)

java.lang.Object
- org.zkoss.poi.poifs.filesystem.POIFSFileSystem

All Implemented Interfaces:

POIFSViewable
```
public class POIFSFileSystem
extends Object
implements POIFSViewable
```
This is the main class of the POIFS system; it manages the entire life cycle of the filesystem.

Author:

Marc Johnson (mjohnson at apache dot org)

Constructor Summary

Constructors
Constructor and Description

POIFSFileSystem()
Constructor, intended for writing

POIFSFileSystem(InputStream stream)
Create a POIFSFileSystem from an InputStream.

Constructors
Constructor and Description
`POIFSFileSystem()` Constructor, intended for writing
`POIFSFileSystem(InputStream stream)` Create a POIFSFileSystem from an `InputStream`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`DirectoryEntry`	`createDirectory(String name)` create a new DirectoryEntry in the root directory
`DocumentEntry`	`createDocument(InputStream stream, String name)` Create a new document to be added to the root directory
`DocumentEntry`	`createDocument(String name, int size, POIFSWriterListener writer)` create a new DocumentEntry in the root entry; the data will be provided later
`DocumentInputStream`	`createDocumentInputStream(String documentName)` open a document in the root entry's list of entries
`static InputStream`	`createNonClosingInputStream(InputStream is)` Convenience method for clients that want to avoid the auto-close behaviour of the constructor.
`int`	`getBigBlockSize()`
`POIFSBigBlockSize`	`getBigBlockSizeDetails()`
`DirectoryNode`	`getRoot()` get the root entry
`String`	`getShortDescription()` Provides a short description of the object, to be used when a POIFSViewable object has not provided its contents.
`Object[]`	`getViewableArray()` Get an array of objects, some of which may implement POIFSViewable
`Iterator`	`getViewableIterator()` Get an Iterator of objects, some of which may implement POIFSViewable
`static boolean`	`hasPOIFSHeader(InputStream inp)` 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.
`static void`	`main(String[] args)` read in a file and write it back out again
`boolean`	`preferArray()` Give viewers a hint as to whether to call getViewableArray or getViewableIterator
`void`	`writeFilesystem(OutputStream stream)` Write the filesystem out

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - POIFSFileSystem
```
public POIFSFileSystem()
```
    Constructor, intended for writing
  - POIFSFileSystem
```
public POIFSFileSystem(InputStream stream)
                throws 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:
    
    IOException - on errors reading, or on invalid data
- Method Detail
  - createNonClosingInputStream
```
public static InputStream createNonClosingInputStream(InputStream is)
```
    Convenience method for clients that want to avoid the auto-close behaviour of the constructor.
  - hasPOIFSHeader
```
public static boolean hasPOIFSHeader(InputStream inp)
                              throws 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:
    
    IOException
  - createDocument
```
public DocumentEntry createDocument(InputStream stream,
                                    String name)
                             throws IOException
```
    Create a new document to be added to the root directory
    
    Parameters:
    
    stream - the InputStream from which the document's data will be obtained
    
    name - the name of the new POIFSDocument
    
    Returns:
    
    the new DocumentEntry
    
    Throws:
    
    IOException - on error creating the new POIFSDocument
  - createDocument
```
public DocumentEntry createDocument(String name,
                                    int size,
                                    POIFSWriterListener writer)
                             throws IOException
```
    create a new DocumentEntry in the root entry; the data will be provided later
    
    Parameters:
    
    name - the name of the new DocumentEntry
    
    size - the size of the new DocumentEntry
    
    writer - the writer of the new DocumentEntry
    
    Returns:
    
    the new DocumentEntry
    
    Throws:
    
    IOException
  - createDirectory
```
public DirectoryEntry createDirectory(String name)
                               throws IOException
```
    create a new DirectoryEntry in the root directory
    
    Parameters:
    
    name - the name of the new DirectoryEntry
    
    Returns:
    
    the new DirectoryEntry
    
    Throws:
    
    IOException - on name duplication
  - writeFilesystem
```
public void writeFilesystem(OutputStream stream)
                     throws IOException
```
    Write the filesystem out
    
    Parameters:
    
    stream - the OutputStream to which the filesystem will be written
    
    Throws:
    
    IOException - thrown on errors writing to the stream
  - main
```
public static void main(String[] args)
                 throws 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:
    
    IOException
  - getRoot
```
public DirectoryNode getRoot()
```
    get the root entry
    
    Returns:
    
    the root entry
  - createDocumentInputStream
```
public DocumentInputStream createDocumentInputStream(String documentName)
                                              throws IOException
```
    open a document in the root entry's list of entries
    
    Parameters:
    
    documentName - the name of the document to be opened
    
    Returns:
    
    a newly opened DocumentInputStream
    
    Throws:
    
    IOException - if the document does not exist or the name is that of a DirectoryEntry
  - getViewableArray
```
public Object[] getViewableArray()
```
    Get an array of objects, some of which may implement POIFSViewable
    
    Specified by:
    
    getViewableArray in interface POIFSViewable
    
    Returns:
    
    an array of Object; may not be null, but may be empty
  - getViewableIterator
```
public Iterator getViewableIterator()
```
    Get an Iterator of objects, some of which may implement POIFSViewable
    
    Specified by:
    
    getViewableIterator in interface POIFSViewable
    
    Returns:
    
    an Iterator; may not be null, but may have an empty back end store
  - preferArray
```
public boolean preferArray()
```
    Give viewers a hint as to whether to call getViewableArray or getViewableIterator
    
    Specified by:
    
    preferArray in interface POIFSViewable
    
    Returns:
    
    true if a viewer should call getViewableArray, false if a viewer should call getViewableIterator
  - getShortDescription
```
public String getShortDescription()
```
    Provides a short description of the object, to be used when a POIFSViewable object has not provided its contents.
    
    Specified by:
    
    getShortDescription in interface POIFSViewable
    
    Returns:
    
    short description
  - getBigBlockSize
```
public int getBigBlockSize()
```
    Returns:
    
    The Big Block size, normally 512 bytes, sometimes 4096 bytes
  - getBigBlockSizeDetails
```
public POIFSBigBlockSize getBigBlockSizeDetails()
```
    Returns:
    
    The Big Block size, normally 512 bytes, sometimes 4096 bytes

Class POIFSFileSystem

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

POIFSFileSystem

POIFSFileSystem

Method Detail

createNonClosingInputStream

hasPOIFSHeader

createDocument

createDocument

createDirectory

writeFilesystem

main

getRoot

createDocumentInputStream

getViewableArray

getViewableIterator

preferArray

getShortDescription

getBigBlockSize

getBigBlockSizeDetails