Package io.goobi.viewer.model.export.bagit

Class BagItWriter

java.lang.Object

io.goobi.viewer.model.export.bagit.BagItWriter

public final class BagItWriter
extends Object

Minimal, dependency-free writer for BagIt bags, serialized as a ZIP.

The caller assembles the payload into <bagRoot>/data/… (arbitrary sub-directory structure) and then calls writeZippedBag(Path, Path, Map, Integer). This class then:

1. writes bagit.txt (version + encoding declaration),
2. computes a SHA-512 digest for every payload file and writes manifest-sha512.txt,
3. writes bag-info.txt (the supplied metadata plus a computed Payload-Oxum and Bag-Size),
4. writes tagmanifest-sha512.txt over the tag files,
5. serializes the whole bag into a ZIP whose single top-level directory is the bag name.

All file I/O is streamed, so bags containing large binary media are handled without loading files into memory. Payload checksums are computed in a single pass while reading each file.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ALGORITHM	Checksum algorithm used for both the payload manifest and the tag manifest.
static final String	BAGIT_VERSION	BagIt version declared in bagit.txt.

Method Summary

Modifier and Type	Method	Description
static void	writeZippedBag(Path bagRoot, Path targetZip, Map<String,String> bagInfo, Integer compressionLevel)	Finalizes the bag rooted at bagRoot (which must already contain a populated data/ directory) by writing its tag files and manifests, then serializes it into targetZip.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BAGIT_VERSION

public static final String BAGIT_VERSION

BagIt version declared in bagit.txt.

See Also:

• Constant Field Values

ALGORITHM

public static final String ALGORITHM

Checksum algorithm used for both the payload manifest and the tag manifest.

See Also:

• Constant Field Values

Method Details

writeZippedBag

public static void writeZippedBag(Path bagRoot,
 Path targetZip,
 Map<String,String> bagInfo,
 Integer compressionLevel)
                           throws IOException

Finalizes the bag rooted at bagRoot (which must already contain a populated data/ directory) by writing its tag files and manifests, then serializes it into targetZip.

Parameters:

bagRoot - the bag root directory containing a data/ payload sub-directory

targetZip - the ZIP file to create (parent directories must exist)

bagInfo - ordered metadata entries for bag-info.txt (e.g. Source-Organization, External-Description); may be null

compressionLevel - ZIP compression level 0-9, or null for the default; use a low value for already-compressed media payloads

Throws:

IOException - on any I/O error