3780fdfe16
git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@352260 13f79535-47bb-0310-9956-ffa450edef68
623 lines
18 KiB
HTML
623 lines
18 KiB
HTML
<html>
|
|
<head>
|
|
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
|
|
<meta content="text/html; charset=ISO-8859-1">
|
|
<title>HPSF HOW-TO</title>
|
|
<style type="text/css">
|
|
body { background-color: white; font-size: normal; color: black ; }
|
|
a { color: #525d76; }
|
|
a.black { color: #000000;}
|
|
table {border-width: 0; width: 100%}
|
|
table.centered {text-align: center}
|
|
table.title {text-align: center; width: 80%}
|
|
img{border-width: 0;}
|
|
span.s1 {font-family: Helvetica, Arial, sans-serif; font-weight: bold; color: #000000; }
|
|
span.s1_white { font-family: Helvetica, Arial, sans-serif; font-weight: bold; color: #ffffff; }
|
|
span.title {font-family: Helvetica, Arial, sans-serif; font-weight: bold; color: #000000; }
|
|
span.c1 {color: #000000; font-family: Helvetica, Arial, sans-serif}
|
|
tr.left {text-align: left}
|
|
hr { width: 100%; size: 2}
|
|
</style>
|
|
</head>
|
|
<body>
|
|
<table width="100%" cellspacing="0" cellpadding="0" border="0">
|
|
<tr>
|
|
<td valign="top" align="left"><a href="http://jakarta.apache.org/index.html"><img hspace="0" vspace="0" border="0" src="images/jakarta-logo.gif"></a></td><td width="100%" valign="top" align="left" bgcolor="#ffffff"><img hspace="0" vspace="0" border="0" align="right" src="images/header.gif"></td>
|
|
</tr>
|
|
<tr>
|
|
<td colspan="2" bgcolor="#525d76"><span class="c1"><a class="black" href="http://www.apache.org/">www.apache.org ></a><a class="black" href="http://jakarta.apache.org/">jakarta.apache.org ></a><a href="http://jakarta.apache.org/poi/" class="black">jakarta.apache.org/poi</a></span></td>
|
|
</tr>
|
|
<tr>
|
|
<td height="8"></td>
|
|
</tr>
|
|
</table>
|
|
<table border="0" cellpadding="0" cellspacing="0" width="100%">
|
|
<tr>
|
|
<td width="1%">
|
|
<br>
|
|
</td><td nowrap="1" valign="top" width="14%">
|
|
<br>
|
|
<span class="s1">Navigation</span>
|
|
<br>
|
|
<a class="s1" href="../index.html">Main</a>
|
|
<br>
|
|
<br>
|
|
<span class="s1">HPSF</span>
|
|
<br>
|
|
<a class="s1" href="index.html">Overview</a>
|
|
<br>
|
|
<a class="s1" href="how-to.html">How To</a>
|
|
<br>
|
|
<a class="s1" href="internals.html">Internals</a>
|
|
<br>
|
|
<a class="s1" href="todo.html">To Do</a>
|
|
<br>
|
|
</td><td width="1%">
|
|
<br>
|
|
</td><td align="left" valign="top" width="*">
|
|
<title>HPSF HOW-TO</title>
|
|
<table width="100%" align="center" class="centered">
|
|
<tbody>
|
|
<tr>
|
|
<td align="center">
|
|
<table border="0" cellpadding="1" cellspacing="0" class="title">
|
|
<tbody>
|
|
<tr>
|
|
<td bgcolor="#525d76">
|
|
<table width="100%" border="0" cellpadding="2" cellspacing="0" class="centered">
|
|
<tbody>
|
|
<tr>
|
|
<td bgcolor="#f3dd61"><span class="title">HPSF HOW-TO</span></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<font size="-2" color="#000000">
|
|
<p>
|
|
<a href="mailto:"></a>
|
|
</p>
|
|
</font>
|
|
<div align="right">
|
|
<table cellspacing="0" cellpadding="2" border="0" width="100%">
|
|
<tr>
|
|
<td bgcolor="#525D76"><font color="#ffffff" size="+1"><font face="Arial,sans-serif"><b>How To Use the HPSF APIs</b></font></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td>
|
|
<br>
|
|
|
|
|
|
<p align="justify">This HOW-TO is organized in three section. You should read them
|
|
sequentially because the later sections build upon the earlier ones.</p>
|
|
|
|
|
|
<ol>
|
|
|
|
<li>
|
|
|
|
<p align="justify">The <a href="#sec1">first section</a> explains how to read
|
|
the most important standard properties of a Microsoft Office
|
|
document. Standard properties are things like title, author, creation
|
|
date etc. It is quite likely that you will find here what you need and
|
|
don't have to read the other sections.</p>
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
<p align="justify">The <a href="#sec2">second section</a> goes a small step
|
|
further and focusses on reading additional standard properties. It also
|
|
talks about exceptions that may be thrown when dealing with HPSF and
|
|
shows how you can read properties of embedded objects.</p>
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
<p align="justify">The <a href="#sec3">third section</a> tells how to read
|
|
non-standard properties. Non-standard properties are application-specific
|
|
name/value/type triples.</p>
|
|
|
|
</li>
|
|
|
|
</ol>
|
|
|
|
|
|
<anchor id="sec1"></anchor>
|
|
|
|
<div align="right">
|
|
<table cellspacing="0" cellpadding="2" border="0" width="99%">
|
|
<tr>
|
|
<td bgcolor="#525D76"><font color="#ffffff" size="+0"><font face="Arial,sans-serif"><b>Reading Standard Properties</b></font></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td>
|
|
<br>
|
|
|
|
|
|
<note>This section explains how to read
|
|
the most important standard properties of a Microsoft Office
|
|
document. Standard properties are things like title, author, creation
|
|
date etc. Chances are that you will find here what you need and
|
|
don't have to read the other sections.</note>
|
|
|
|
|
|
<p align="justify">The first thing you should understand is that properties are stored in
|
|
separate documents inside the POI filesystem. (If you don't know what a
|
|
POI filesystem is, read its <a href="../poifs/index.html">documentation</a>.) A document in a POI
|
|
filesystem is also called a <em>stream</em>.</p>
|
|
|
|
|
|
<p align="justify">The following example shows how to read a POI filesystem's
|
|
"title" property. Reading other properties is similar. Consider the API
|
|
documentation of <code>org.apache.poi.hpsf.SummaryInformation</code>.</p>
|
|
|
|
|
|
<p align="justify">The standard properties this section focusses on can be
|
|
found in a document called <em>\005SummaryInformation</em> in the root of
|
|
the POI filesystem. The notation <em>\005</em> in the document's name
|
|
means the character with the decimal value of 5. In order to read the
|
|
title, an application has to perform the following steps:</p>
|
|
|
|
|
|
<ol>
|
|
|
|
<li>
|
|
|
|
<p align="justify">Open the document <em>\005SummaryInformation</em> located in the root
|
|
of the POI filesystem.</p>
|
|
|
|
</li>
|
|
|
|
<li>
|
|
|
|
<p align="justify">Create an instance of the class
|
|
<code>SummaryInformation</code> from that
|
|
document.</p>
|
|
|
|
</li>
|
|
|
|
<li>
|
|
|
|
<p align="justify">Call the <code>SummaryInformation</code> instance's
|
|
<code>getTitle()</code> method.</p>
|
|
|
|
</li>
|
|
|
|
</ol>
|
|
|
|
|
|
<p align="justify">Sounds easy, doesn't it? Here are the steps in detail.</p>
|
|
|
|
|
|
|
|
<div align="right">
|
|
<table cellspacing="0" cellpadding="2" border="0" width="98%">
|
|
<tr>
|
|
<td bgcolor="#525D76"><font color="#ffffff" size="-1"><font face="Arial,sans-serif"><b>Open the document \005SummaryInformation in the root of the POI filesystem</b></font></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td>
|
|
<br>
|
|
|
|
|
|
<p align="justify">An application that wants to open a document in a POI filesystem
|
|
(POIFS) proceeds as shown by the following code fragment. (The full
|
|
source code of the sample application is available in the
|
|
<em>examples</em> section of the POI source tree as
|
|
<em>ReadTitle.java</em>.)</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>
|
|
import java.io.*;
|
|
import org.apache.poi.hpsf.*;
|
|
import org.apache.poi.poifs.eventfilesystem.*;
|
|
|
|
// ...
|
|
|
|
public static void main(String[] args)
|
|
throws IOException
|
|
{
|
|
final String filename = args[0];
|
|
POIFSReader r = new POIFSReader();
|
|
r.registerListener(new MyPOIFSReaderListener(),
|
|
"\005SummaryInformation");
|
|
r.read(new FileInputStream(filename));
|
|
}</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">The first interesting statement is</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>POIFSReader r = new POIFSReader();</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">It creates a
|
|
<code>org.apache.poi.poifs.eventfilesystem.POIFSReader</code> instance
|
|
which we shall need to read the POI filesystem. Before the application
|
|
actually opens the POI filesystem we have to tell the
|
|
<code>POIFSReader</code> which documents we are interested in. In this
|
|
case the application should do something with the document
|
|
<em>\005SummaryInformation</em>.</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>
|
|
r.registerListener(new MyPOIFSReaderListener(),
|
|
"\005SummaryInformation");</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">This method call registers a
|
|
<code>org.apache.poi.poifs.eventfilesystem.POIFSReaderListener</code>
|
|
with the <code>POIFSReader</code>. The <code>POIFSReaderListener</code>
|
|
interface specifies the method <code>processPOIFSReaderEvent</code>
|
|
which processes a document. The class
|
|
<code>MyPOIFSReaderListener</code> implements the
|
|
<code>POIFSReaderListener</code> and thus the
|
|
<code>processPOIFSReaderEvent</code> method. The eventing POI filesystem
|
|
calls this method when it finds the <em>\005SummaryInformation</em>
|
|
document. In the sample application <code>MyPOIFSReaderListener</code> is
|
|
a static class in the <em>ReadTitle.java</em> source file.)</p>
|
|
|
|
|
|
<p align="justify">Now everything is prepared and reading the POI filesystem can
|
|
start:</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>r.read(new FileInputStream(filename));</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">The following source code fragment shows the
|
|
<code>MyPOIFSReaderListener</code> class and how it retrieves the
|
|
title.</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>
|
|
static class MyPOIFSReaderListener implements POIFSReaderListener
|
|
{
|
|
public void processPOIFSReaderEvent(POIFSReaderEvent e)
|
|
{
|
|
SummaryInformation si = null;
|
|
try
|
|
{
|
|
si = (SummaryInformation)
|
|
PropertySetFactory.create(e.getStream());
|
|
}
|
|
catch (Exception ex)
|
|
{
|
|
throw new RuntimeException
|
|
("Property set stream \"" +
|
|
event.getPath() + event.getName() + "\": " + ex);
|
|
}
|
|
final String title = si.getTitle();
|
|
if (title != null)
|
|
System.out.println("Title: \"" + title + "\"");
|
|
else
|
|
System.out.println("Document has no title.");
|
|
}
|
|
}
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">The line</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>SummaryInformation si = null;</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">declares a <code>SummaryInformation</code> variable and initializes it
|
|
with <code>null</code>. We need an instance of this class to access the
|
|
title. The instance is created in a <code>try</code> block:</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>si = (SummaryInformation)
|
|
PropertySetFactory.create(e.getStream());</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">The expression <code>e.getStream()</code> returns the input stream
|
|
containing the bytes of the property set stream named
|
|
<em>\005SummaryInformation</em>. This stream is passed into the
|
|
<code>create</code> method of the factory class
|
|
<code>org.apache.poi.hpsf.PropertySetFactory</code> which returns
|
|
a <code>org.apache.poi.hpsf.PropertySet</code> instance. It is more or
|
|
less safe to cast this result to <code>SummaryInformation</code>, a
|
|
convenience class with methods like <code>getTitle()</code>,
|
|
<code>getAuthor()</code> etc.</p>
|
|
|
|
|
|
<p align="justify">The <code>PropertySetFactory.create</code> method may throw all sorts
|
|
of exceptions. We'll deal with them in the next sections. For now we just
|
|
catch all exceptions and throw a <code>RuntimeException</code>
|
|
containing the message text of the origin exception.</p>
|
|
|
|
|
|
<p align="justify">If all goes well, the sample application retrieves the title and prints
|
|
it to the standard output. As you can see you must be prepared for the
|
|
case that the POI filesystem does not have a title.</p>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td>
|
|
<pre>final String title = si.getTitle();
|
|
if (title != null)
|
|
System.out.println("Title: \"" + title + "\"");
|
|
else
|
|
System.out.println("Document has no title.");</pre>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
|
|
<p align="justify">Please note that a Microsoft Office document does not necessarily
|
|
contain the <em>\005SummaryInformation</em> stream. The documents created
|
|
by the Microsoft Office suite have one, as far as I know. However, an
|
|
Excel spreadsheet exported from StarOffice 5.2 won't have a
|
|
<em>\005SummaryInformation</em> stream. In this case the applications
|
|
won't throw an exception but simply does not call the
|
|
<code>processPOIFSReaderEvent</code> method. You have been warned!</p>
|
|
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br>
|
|
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br>
|
|
|
|
|
|
<anchor id="sec2"></anchor>
|
|
|
|
<div align="right">
|
|
<table cellspacing="0" cellpadding="2" border="0" width="99%">
|
|
<tr>
|
|
<td bgcolor="#525D76"><font color="#ffffff" size="+0"><font face="Arial,sans-serif"><b>Additional Standard Properties, Exceptions And Embedded Objects</b></font></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td>
|
|
<br>
|
|
|
|
|
|
<note>This section focusses on reading additional standard properties. It
|
|
also talks about exceptions that may be thrown when dealing with HPSF and
|
|
shows how you can read properties of embedded objects.</note>
|
|
|
|
|
|
<p align="justify">A couple of <em>additional standard properties</em> are not
|
|
contained in the <em>\005SummaryInformation</em> stream explained above,
|
|
for example a document's category or the number of multimedia clips in a
|
|
PowerPoint presentation. Microsoft has invented an additional stream named
|
|
<em>\005DocumentSummaryInformation</em> to hold these properties. With two
|
|
minor exceptions you can proceed exactly as described above to read the
|
|
properties stored in <em>\005DocumentSummaryInformation</em>:</p>
|
|
|
|
|
|
<ul>
|
|
|
|
<li>
|
|
<p align="justify">Instead of <em>\005SummaryInformation</em> use
|
|
<em>\005DocumentSummaryInformation</em> as the stream's name.</p>
|
|
</li>
|
|
|
|
<li>
|
|
<p align="justify">Replace all occurrences of the class
|
|
<code>SummaryInformation</code> by
|
|
<code>DocumentSummaryInformation</code>.</p>
|
|
</li>
|
|
|
|
</ul>
|
|
|
|
|
|
<p align="justify">And of course you cannot call <code>getTitle()</code> because
|
|
<code>DocumentSummaryInformation</code> has different query methods. See
|
|
the API documentation for the details!</p>
|
|
|
|
|
|
<p align="justify">In the previous section the application simply caught all
|
|
<em>exceptions</em> and was in no way interested in any
|
|
details. However, a real application will likely want to know what went
|
|
wrong and act appropriately. Besides any IO exceptions there are three
|
|
HPSF resp. POI specific exceptions you should know about:</p>
|
|
|
|
|
|
<dl>
|
|
|
|
<dt>
|
|
<code>NoPropertySetStreamException</code>:</dt>
|
|
|
|
<dd>
|
|
<p align="justify">This exception is thrown if the application tries to create a
|
|
<code>PropertySet</code> or one of its subclasses
|
|
<code>SummaryInformation</code> and
|
|
<code>DocumentSummaryInformation</code> from a stream that is not a
|
|
property set stream. A faulty property set stream counts as not being a
|
|
property set stream at all. An application should be prepared to deal
|
|
with this case even if opens streams named
|
|
<em>\005SummaryInformation</em> or
|
|
<em>\005DocumentSummaryInformation</em> only. These are just names. A
|
|
stream's name by itself does not ensure that the stream contains the
|
|
expected contents and that this contents is correct.</p>
|
|
</dd>
|
|
|
|
|
|
<dt>
|
|
<code>UnexpectedPropertySetTypeException</code>
|
|
</dt>
|
|
|
|
<dd>
|
|
<p align="justify">This exception is thrown if a certain type of property set is
|
|
expected somewhere (e.g. a <code>SummaryInformation</code> or
|
|
<code>DocumentSummaryInformation</code>) but the provided property
|
|
set is not of that type.</p>
|
|
</dd>
|
|
|
|
|
|
<dt>
|
|
<code>MarkUnsupportedException</code>
|
|
</dt>
|
|
|
|
<dd>
|
|
<p align="justify">This exception is thrown if an input stream that is to be parsed
|
|
into a property set does not support the
|
|
<code>InputStream.mark(int)</code> operation. The POI filesystem uses
|
|
the <code>DocumentInputStream</code> class which does support this
|
|
operation, so you are safe here. However, if you read a property set
|
|
stream from another kind of input stream things may be
|
|
different.</p>
|
|
</dd>
|
|
|
|
</dl>
|
|
|
|
|
|
<p align="justify">Many Microsoft Office documents contain <em>embedded
|
|
objects</em>, for example an Excel sheet on a page in a Word
|
|
document. Embedded objects may have property sets of their own. An
|
|
application can open these property set streams as described above. The
|
|
only difference is that they are not located in the POI filesystem's root
|
|
but in a nested directory instead. Just register a
|
|
<code>POIFSReaderListener</code> for the property set streams you are
|
|
interested in. For example, the <em>POIBrowser</em> application in the
|
|
contrib section tries to open each and every document in a POI filesystem
|
|
as a property set stream. If this operation was successful it displays the
|
|
properties.</p>
|
|
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br>
|
|
|
|
|
|
<anchor id="sec3"></anchor>
|
|
|
|
<div align="right">
|
|
<table cellspacing="0" cellpadding="2" border="0" width="99%">
|
|
<tr>
|
|
<td bgcolor="#525D76"><font color="#ffffff" size="+0"><font face="Arial,sans-serif"><b>Reading Non-Standard Properties</b></font></font></td>
|
|
</tr>
|
|
<tr>
|
|
<td>
|
|
<br>
|
|
|
|
|
|
<note>This section tells how to read
|
|
non-standard properties. Non-standard properties are application-specific
|
|
name/value/type triples.</note>
|
|
|
|
|
|
<div align="center">
|
|
<table cellspacing="2" cellpadding="2" border="1">
|
|
<tr>
|
|
<td bgcolor="#c0c0c0"><font size="-1" color="#023264">Write this section!</font></td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br>
|
|
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
</div>
|
|
<br>
|
|
</td>
|
|
</tr>
|
|
</table>
|
|
<br>
|
|
<table width="100%" border="0" cellspacing="0" cellpadding="0">
|
|
<tbody>
|
|
<tr>
|
|
<td>
|
|
<hr noshade="" size="1">
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td align="center"><i>Copyright © 2002 Apache Software Foundation</i></td>
|
|
</tr>
|
|
<tr>
|
|
<td align="right" width="100%">
|
|
<br>
|
|
</td>
|
|
</tr>
|
|
<tr>
|
|
<td align="right" width="100%"><a href="http://krysalis.org/"><img alt="Krysalis Logo" src="images/krysalis-compatible.jpg"></a><a href="http://xml.apache.org/cocoon/"><img alt="Cocoon Logo" src="images/built-with-cocoon.gif"></a></td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</body>
|
|
</html>
|