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Item Importer and Exporter

DSpace has a set of command line tools for importing and exporting items in batches, using the DSpace simple archive format. The tools are not terribly robust, but are useful and are easily modified. They also give a good demonstration of how to implement your own item importer if desiredSimple Archive Format. Apart from the offered functionality, these tools serve as a prime example for users who aim to implement their own item importer.

DSpace Simple Archive Format

The basic concept behind the DSpace's simple archive format Simple Archive Format is to create an archive, which is directory full of items, with a subdirectory per item. Each item directory contains a file for the item's descriptive metadata, and the files that make up the item.

Code Block

archive_directory/
    item_000/
        dublin_core.xml         -- qualified Dublin Core metadata for metadata fields belonging to the dc schema
        metadata_[prefix].xml   -- metadata in another schema, the prefix is the name of the schema as registered with the metadata registry
        contents                -- text file containing one line per filename
        file_1.doc              -- files to be added as bitstreams to the item
        file_2.pdf
    item_001/
        dublin_core.xml
        contents
        file_1.png
        ...

...

  • <element> - the Dublin Core element
  • <qualifier> - the element's qualifier

  • <language>- (optional)ISO language code for element

    Code Block
    
<dublin_core>
    <dcvalue element="title" qualifier="none">A Tale of Two Cities</dcvalue>
    <dcvalue element="date" qualifier="issued">1990</dcvalue>
    <dcvalue element="title" qualifier="alternatealternative" language="fr">J'aime les Printemps</dcvalue>
</dublin_core>

    (Note the optional language tag attribute which notifies the system that the optional title is in French.)

Every metadata field used, must be registered via the metadata registry of the DSpace instance first.

The contents file simply enumerates, one file per line, the bitstream file names. See the following example:

Code Block

file_1.doc
        file_2.pdf
        license

...

  1. Create a separate file for the other schema named metadata_[prefix].xml, where the [prefix] is replaced with the schema's prefix.
  2. Inside the xml file use the dame Dublin Core syntax, but on the <dublin_core> element include the attribute schema=[prefix].

  3. Here is an example for ETD metadata, which would be in the file metadata_etd.xml:

    Code Block
    <?xml version="1.0" encoding="UTF-8"?>
<dublin_core schema="etd">
     <dcvalue element="degree" qualifier="department">Computer Science</dcvalue>
     <dcvalue element="degree" qualifier="level">Masters</dcvalue>
     <dcvalue element="degree" qualifier="grantor">Texas A & M</dcvalue>
</dublin_core>

...

Code Block
[dspace]/bin/dspace import -e joe@user.com -d -m mapfile

In long form:

Code Block
[dspace]/bin/dspace import --eperson=joe@user.com --delete --mapfile mapfile

...

The item exporter can export a single item or a collection of items, and creates a DSpace simple archive according to the aforementioned format for each item to be exported. The items are exported in a sequential order in which they are retrieved from the database. As a consequence, the sequence numbers of the item subdirectories (item_000, item_001) are not related to DSpace handle or item id's.

Command used:

[dspace]/bin/dspace export

Java class:

org.dspace.app.itemexport.ItemExport

Arguments short and (long) forms:

Description

-t or --type

Type of export. COLLECTION will inform the program you want the whole collection. ITEM will be only the specific item. (You will actually key in the keywords in all caps. See examples below.)

-i or --id

The ID or Handle of the Collection or Item to export.

-d or --dest

The destination of where you want the file of items to be placed. You place the path if necessary.

-n or --number

Sequence number to begin export the items with. Whatever number you give, this will be the name of the first directory created for your export. The layout of the export is the same as you would set your layout for an Import.

-m or --migrate

Export the item/collection for migration. This will remove the handle and metadata that will be re-created in the new instance of DSpace.

-h or --help

Brief Help.

...

Using the -m argument will export the item/collection and also perform the migration step. It will perform the same process that the next section Transferring Items Between DSpace Instances performsor Copying Content Between Repositories performs. We recommend that the next section to be read in conjunction with this flag being used.