org.apache.poi.hpsf.examples.CopyCompare Maven / Gradle / Ivy
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package org.apache.poi.hpsf.examples;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.Map;
import org.apache.poi.hpsf.DocumentSummaryInformation;
import org.apache.poi.hpsf.HPSFRuntimeException;
import org.apache.poi.hpsf.MarkUnsupportedException;
import org.apache.poi.hpsf.NoPropertySetStreamException;
import org.apache.poi.hpsf.PropertySet;
import org.apache.poi.hpsf.PropertySetFactory;
import org.apache.poi.hpsf.SummaryInformation;
import org.apache.poi.hpsf.UnexpectedPropertySetTypeException;
import org.apache.poi.hpsf.WritingNotSupportedException;
import org.apache.poi.poifs.eventfilesystem.POIFSReader;
import org.apache.poi.poifs.eventfilesystem.POIFSReaderEvent;
import org.apache.poi.poifs.eventfilesystem.POIFSReaderListener;
import org.apache.poi.poifs.filesystem.DirectoryEntry;
import org.apache.poi.poifs.filesystem.DocumentInputStream;
import org.apache.poi.poifs.filesystem.EntryUtils;
import org.apache.poi.poifs.filesystem.POIFSDocumentPath;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import org.apache.poi.util.TempFile;
/**
* This class copies a POI file system to a new file and compares the copy
* with the original.
*
*
Property set streams are copied logically, i.e. the application
* establishes a {@link org.apache.poi.hpsf.PropertySet} of an original property
* set, creates a {@link org.apache.poi.hpsf.PropertySet} and writes the
* {@link org.apache.poi.hpsf.PropertySet} to the destination POI file
* system. - Streams which are no property set streams are copied bit by
* bit.
*
*
The comparison of the POI file systems is done logically. That means that
* the two disk files containing the POI file systems do not need to be
* exactly identical. However, both POI file systems must contain the same
* files, and most of these files must be bitwise identical. Property set
* streams, however, are compared logically: they must have the same sections
* with the same attributes, and the sections must contain the same properties.
* Details like the ordering of the properties do not matter.
*/
public final class CopyCompare {
private CopyCompare() {}
/**
* Runs the example program. The application expects one or two arguments:
*
*
* - The first argument is the disk file name of the POI filesystem to copy.
* - The second argument is optional. If it is given, it is the name of
* a disk file the copy of the POI filesystem will be written to. If it is
* not given, the copy will be written to a temporary file which will be
* deleted at the end of the program.
*
*
* @param args Command-line arguments.
* @throws IOException if any I/O exception occurs.
* @throws UnsupportedEncodingException if a character encoding is not
* supported.
*/
public static void main(final String[] args)
throws UnsupportedEncodingException, IOException {
String originalFileName = null;
String copyFileName = null;
/* Check the command-line arguments. */
if (args.length == 1) {
originalFileName = args[0];
File f = TempFile.createTempFile("CopyOfPOIFileSystem-", ".ole2");
f.deleteOnExit();
copyFileName = f.getAbsolutePath();
} else if (args.length == 2) {
originalFileName = args[0];
copyFileName = args[1];
} else {
System.err.println("Usage: " + CopyCompare.class.getName() +
"originPOIFS [copyPOIFS]");
System.exit(1);
}
/* Read the origin POIFS using the eventing API. The real work is done
* in the class CopyFile which is registered here as a POIFSReader. */
final POIFSReader r = new POIFSReader();
final CopyFile cf = new CopyFile(copyFileName);
r.registerListener(cf);
r.setNotifyEmptyDirectories(true);
r.read(new File(originalFileName));
/* Write the new POIFS to disk. */
cf.close();
/* Read all documents from the original POI file system and compare them
* with the equivalent document from the copy. */
try (POIFSFileSystem opfs = new POIFSFileSystem(new File(originalFileName));
POIFSFileSystem cpfs = new POIFSFileSystem(new File(copyFileName))) {
final DirectoryEntry oRoot = opfs.getRoot();
final DirectoryEntry cRoot = cpfs.getRoot();
System.out.println(EntryUtils.areDirectoriesIdentical(oRoot, cRoot) ? "Equal" : "Not equal");
}
}
/**
* This class does all the work. Its method {@link
* #processPOIFSReaderEvent(POIFSReaderEvent)} is called for each file in
* the original POI file system. Except for property set streams it copies
* everything unmodified to the destination POI filesystem. Property set
* streams are copied by creating a new {@link PropertySet} from the
* original property set by using the {@link
* PropertySet#PropertySet(PropertySet)} constructor.
*/
static class CopyFile implements POIFSReaderListener {
private String dstName;
private OutputStream out;
private POIFSFileSystem poiFs;
/**
* The constructor of a {@link CopyFile} instance creates the target
* POIFS. It also stores the name of the file the POIFS will be written
* to once it is complete.
*
* @param dstName The name of the disk file the destination POIFS is to
* be written to.
*/
CopyFile(final String dstName) {
this.dstName = dstName;
poiFs = new POIFSFileSystem();
}
/**
* The method is called by POI's eventing API for each file in the
* origin POIFS.
*/
@Override
public void processPOIFSReaderEvent(final POIFSReaderEvent event) {
/* The following declarations are shortcuts for accessing the
* "event" object. */
final POIFSDocumentPath path = event.getPath();
final String name = event.getName();
final DocumentInputStream stream = event.getStream();
Throwable t = null;
try {
/* Find out whether the current document is a property set
* stream or not. */
if (stream != null && PropertySet.isPropertySetStream(stream)) {
/* Yes, the current document is a property set stream.
* Let's create a PropertySet instance from it. */
PropertySet ps = null;
try {
ps = PropertySetFactory.create(stream);
} catch (NoPropertySetStreamException ex) {
/* This exception will not be thrown because we already
* checked above. */
}
/* Copy the property set to the destination POI file
* system. */
copy(poiFs, path, name, ps);
} else {
/* No, the current document is not a property set stream. We
* copy it unmodified to the destination POIFS. */
copy(poiFs, path, name, stream);
}
} catch (MarkUnsupportedException | WritingNotSupportedException | IOException ex) {
t = ex;
}
/* According to the definition of the processPOIFSReaderEvent method
* we cannot pass checked exceptions to the caller. The following
* lines check whether a checked exception occurred and throws an
* unchecked exception. The message of that exception is that of
* the underlying checked exception. */
if (t != null) {
throw new HPSFRuntimeException("Could not read file \"" + path + "/" + name, t);
}
}
/**
* Writes a {@link PropertySet} to a POI filesystem.
*
* @param poiFs The POI filesystem to write to.
* @param path The file's path in the POI filesystem.
* @param name The file's name in the POI filesystem.
* @param ps The property set to write.
*/
public void copy(final POIFSFileSystem poiFs,
final POIFSDocumentPath path,
final String name,
final PropertySet ps)
throws WritingNotSupportedException, IOException {
final DirectoryEntry de = getPath(poiFs, path);
final PropertySet mps;
try {
if (ps instanceof DocumentSummaryInformation) {
mps = new DocumentSummaryInformation(ps);
} else if (ps instanceof SummaryInformation) {
mps = new SummaryInformation(ps);
} else {
mps = new PropertySet(ps);
}
} catch (UnexpectedPropertySetTypeException e) {
throw new IOException(e);
}
de.createDocument(name, mps.toInputStream());
}
/**
* Copies the bytes from a {@link DocumentInputStream} to a new
* stream in a POI filesystem.
*
* @param poiFs The POI filesystem to write to.
* @param path The source document's path.
* @param name The source document's name.
* @param stream The stream containing the source document.
*/
public void copy(final POIFSFileSystem poiFs,
final POIFSDocumentPath path,
final String name,
final DocumentInputStream stream)
throws IOException {
// create the directories to the document
final DirectoryEntry de = getPath(poiFs, path);
// check the parameters after the directories have been created
if (stream == null || name == null) {
// Empty directory
return;
}
final ByteArrayOutputStream out = new ByteArrayOutputStream();
int c;
while ((c = stream.read()) != -1) {
out.write(c);
}
stream.close();
out.close();
final InputStream in =
new ByteArrayInputStream(out.toByteArray());
de.createDocument(name, in);
}
/**
* Writes the POI file system to a disk file.
*/
public void close() throws IOException {
out = new FileOutputStream(dstName);
poiFs.writeFilesystem(out);
out.close();
}
/**
* Contains the directory paths that have already been created in the
* output POI filesystem and maps them to their corresponding
* {@link org.apache.poi.poifs.filesystem.DirectoryNode}s.
*/
private final Map paths = new HashMap<>();
/**
* Ensures that the directory hierarchy for a document in a POI
* fileystem is in place. When a document is to be created somewhere in
* a POI filesystem its directory must be created first. This method
* creates all directories between the POI filesystem root and the
* directory the document should belong to which do not yet exist.
*
*
Unfortunately POI does not offer a simple method to interrogate
* the POIFS whether a certain child node (file or directory) exists in
* a directory. However, since we always start with an empty POIFS which
* contains the root directory only and since each directory in the
* POIFS is created by this method we can maintain the POIFS's directory
* hierarchy ourselves: The {@link DirectoryEntry} of each directory
* created is stored in a {@link Map}. The directories' path names map
* to the corresponding {@link DirectoryEntry} instances.
*
* @param poiFs The POI filesystem the directory hierarchy is created
* in, if needed.
* @param path The document's path. This method creates those directory
* components of this hierarchy which do not yet exist.
* @return The directory entry of the document path's parent. The caller
* should use this {@link DirectoryEntry} to create documents in it.
*/
public DirectoryEntry getPath(final POIFSFileSystem poiFs,
final POIFSDocumentPath path) {
try {
/* Check whether this directory has already been created. */
final String s = path.toString();
DirectoryEntry de = paths.get(s);
if (de != null)
/* Yes: return the corresponding DirectoryEntry. */
return de;
/* No: We have to create the directory - or return the root's
* DirectoryEntry. */
int l = path.length();
if (l == 0) {
/* Get the root directory. It does not have to be created
* since it always exists in a POIFS. */
de = poiFs.getRoot();
} else {
/* Create a subordinate directory. The first step is to
* ensure that the parent directory exists: */
de = getPath(poiFs, path.getParent());
/* Now create the target directory: */
de = de.createDirectory(path.getComponent
(path.length() - 1));
}
paths.put(s, de);
return de;
} catch (IOException ex) {
/* This exception will be thrown if the directory already
* exists. However, since we have full control about directory
* creation we can ensure that this will never happen. */
throw new RuntimeException(ex);
}
}
}
}