itemexport.java

dspace 用j2ee架构的一个数字图书馆.开源程序

    }

    private static void exportItem(Context c, ItemIterator i,
            String destDirName, int seqStart) throws Exception
    {
        int mySequenceNumber = seqStart;

        System.out.println("Beginning export");

        while (i.hasNext())
        {
            System.out.println("Exporting item to " + mySequenceNumber);
            exportItem(c, i.next(), destDirName, mySequenceNumber);
            mySequenceNumber++;
        }
    }

    private static void exportItem(Context c, Item myItem, String destDirName,
            int seqStart) throws Exception
    {
        File destDir = new File(destDirName);

        if (destDir.exists())
        {
            // now create a subdirectory
            File itemDir = new File(destDir + "/" + seqStart);

            System.out.println("Exporting Item " + myItem.getID() + " to "
                    + itemDir);

            if (itemDir.exists())
            {
                throw new Exception("Directory " + destDir + "/" + seqStart
                        + " already exists!");
            }

            if (itemDir.mkdir())
            {
                // make it this far, now start exporting
                writeMetadata(c, myItem, itemDir);
                writeBitstreams(c, myItem, itemDir);
                writeHandle(c, myItem, itemDir);
            }
            else
            {
                throw new Exception("Error, can't make dir " + itemDir);
            }
        }
        else
        {
            throw new Exception("Error, directory " + destDirName
                    + " doesn't exist!");
        }
    }

    /**
     * Discover the different schemas in use and output a seperate metadata
     * XML file for each schema.
     *
     * @param c
     * @param i
     * @param destDir
     * @throws Exception
     */
    private static void writeMetadata(Context c, Item i, File destDir)
            throws Exception
    {
        // Build a list of schemas for the item
        HashMap map = new HashMap();
        DCValue[] dcorevalues = i.getMetadata(Item.ANY, Item.ANY, Item.ANY, Item.ANY);
        for (int ii = 0; ii < dcorevalues.length; ii++)
        {
            map.put(dcorevalues[ii].schema, null);
        }

        // Save each of the schemas into it's own metadata file
        Iterator iterator = map.keySet().iterator();
        while (iterator.hasNext())
        {
            String schema = (String) iterator.next();
            writeMetadata(c, schema, i, destDir);
        }
    }

    // output the item's dublin core into the item directory
    private static void writeMetadata(Context c, String schema, Item i, File destDir)
            throws Exception
    {
        String filename;
        if (schema.equals(MetadataSchema.DC_SCHEMA)) {
            filename = "dublin_core.xml";
        } else {
            filename = "metadata_" + schema + ".xml";
        }
        
        File outFile = new File(destDir, filename);

        System.out.println("Attempting to create file " + outFile);

        if (outFile.createNewFile())
        {
            BufferedOutputStream out = new BufferedOutputStream(
                    new FileOutputStream(outFile));

            DCValue[] dcorevalues = i.getMetadata(schema, Item.ANY, Item.ANY, Item.ANY);

            // XML preamble
            byte[] utf8 = "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n"
                    .getBytes("UTF-8");
            out.write(utf8, 0, utf8.length);

            String dcTag = "<dublin_core schema=\""+schema+"\">\n";
            utf8 = dcTag.getBytes("UTF-8");
            out.write(utf8, 0, utf8.length);

            for (int j = 0; j < dcorevalues.length; j++)
            {
                DCValue dcv = dcorevalues[j];
                String qualifier = dcv.qualifier;

                if (qualifier == null)
                {
                    qualifier = "none";
                }

                utf8 = ("  <dcvalue element=\"" + dcv.element + "\" "
                        + "qualifier=\"" + qualifier + "\">"
                        + Utils.addEntities(dcv.value) + "</dcvalue>\n").getBytes("UTF-8");

                out.write(utf8, 0, utf8.length);
            }

            utf8 = "</dublin_core>\n".getBytes("UTF-8");
            out.write(utf8, 0, utf8.length);

            out.close();
        }
        else
        {
            throw new Exception("Cannot create dublin_core.xml in " + destDir);
        }
    }

    // create the file 'handle' which contains the handle assigned to the item
    private static void writeHandle(Context c, Item i, File destDir)
            throws Exception
    {
        String filename = "handle";

        File outFile = new File(destDir, filename);

        if (outFile.createNewFile())
        {
            PrintWriter out = new PrintWriter(new FileWriter(outFile));

            out.println(i.getHandle());

            // close the contents file
            out.close();
        }
        else
        {
            throw new Exception("Cannot create file " + filename + " in "
                    + destDir);
        }
    }

    /**
     * Create both the bitstreams and the contents file. Any bitstreams that
     * were originally registered will be marked in the contents file as such.
     * However, the export directory will contain actual copies of the content
     * files being exported.
     * 
     * @param c the DSpace context
     * @param i the item being exported
     * @param destDir the item's export directory
     * @throws Exception if there is any problem writing to the export 
     * 		directory
     */
    private static void writeBitstreams(Context c, Item i, File destDir)
            throws Exception
    {
        File outFile = new File(destDir, "contents");

        if (outFile.createNewFile())
        {
            PrintWriter out = new PrintWriter(new FileWriter(outFile));

            Bundle[] bundles = i.getBundles();

            for (int j = 0; j < bundles.length; j++)
            {
                // bundles can have multiple bitstreams now...
                Bitstream[] bitstreams = bundles[j].getBitstreams();

                String bundleName = bundles[j].getName();

                for (int k = 0; k < bitstreams.length; k++)
                {
                    Bitstream b = bitstreams[k];

                    String myName = b.getName();
                    String oldName = myName;
                    int myPrefix = 1; // only used with name conflict

                    InputStream is = b.retrieve();

                    boolean isDone = false; // done when bitstream is finally
                                            // written

                    while (!isDone)
                    {
                        File fout = new File(destDir, myName);

                        if (fout.createNewFile())
                        {
                            FileOutputStream fos = new FileOutputStream(fout);
                            Utils.bufferedCopy(is, fos);
                            // close streams
                            is.close();
                            fos.close();

                            // write the manifest file entry
                            if (b.isRegisteredBitstream()) {
                                out.println("-r -s " + b.getStoreNumber() 
                                		+ " -f " + myName 
										+ "\tbundle:" + bundleName);
                            } else {
                                out.println(myName + "\tbundle:" + bundleName);
                            }

                            isDone = true;
                        }
                        else
                        {
                            myName = myPrefix + "_" + oldName; // keep appending
                                                               // numbers to the
                                                               // filename until
                                                               // unique
                            myPrefix++;
                        }
                    }
                }
            }

            // close the contents file
            out.close();
        }
        else
        {
            throw new Exception("Cannot create contents in " + destDir);
        }
    }
}