Java tutorial
/** * The contents of this file are subject to the license and copyright * detailed in the LICENSE and NOTICE files at the root of the source * tree and available online at * * http://www.dspace.org/license/ */ package org.dspace.app.oai; import java.io.BufferedInputStream; import java.io.InputStream; import java.io.IOException; import java.sql.SQLException; import java.util.Date; import java.util.Properties; import org.apache.commons.codec.binary.Base64; import org.apache.log4j.Logger; import org.dspace.app.didl.UUIDFactory; import org.dspace.content.Bitstream; import org.dspace.content.Bundle; import org.dspace.content.Item; import org.dspace.core.ConfigurationManager; import org.dspace.core.Context; import org.dspace.search.HarvestedItemInfo; import org.dspace.storage.bitstore.BitstreamStorageManager; import ORG.oclc.oai.server.crosswalk.Crosswalk; import ORG.oclc.oai.server.verb.CannotDisseminateFormatException; import ORG.oclc.oai.server.verb.ServerVerb; /** * DSpace Item DIDL crosswalk. * * Development of this code was part of the aDORe repository project * by the Research Library of the Los Alamos National Laboratory. * * @author Henry Jerez * @author Los Alamos National Laboratory */ public class DIDLCrosswalk extends Crosswalk { private static final Logger log = Logger.getLogger(DIDLCrosswalk.class); /** default value if no oai.didl.maxresponse property is defined */ public static final int MAXRESPONSE_INLINE_BITSTREAM = 0; /** another crosswalk that will be used to generate the metadata section */ private Crosswalk metadataCrosswalk; public DIDLCrosswalk(Properties properties) { super("urn:mpeg:mpeg21:2002:02-DIDL-NS http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-21_schema_files/did/didl.xsd "); // FIXME this should be injected from the configuration... // but it is better than duplicate the OAIDCCrosswalk code! metadataCrosswalk = new OAIDCCrosswalk(properties); } public boolean isAvailableFor(Object nativeItem) { // We have DC for everything return true; } public String createMetadata(Object nativeItem) throws CannotDisseminateFormatException { Item item = ((HarvestedItemInfo) nativeItem).item; StringBuffer metadata = new StringBuffer(); String itemhandle = item.getHandle(); String strMaxSize = ConfigurationManager.getProperty("oai", "didl.maxresponse"); int maxsize = MAXRESPONSE_INLINE_BITSTREAM; if (strMaxSize != null) { maxsize = Integer.parseInt(strMaxSize); } String currdate = ServerVerb.createResponseDate(new Date()); metadata.append("<didl:DIDL ").append(" xmlns:didl=\"urn:mpeg:mpeg21:2002:02-DIDL-NS\" ") .append(" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" ") .append("xsi:schemaLocation=\"urn:mpeg:mpeg21:2002:02-DIDL-NS http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-21_schema_files/did/didl.xsd \">") .append("<didl:DIDLInfo>") .append("<dcterms:created xmlns:dcterms=\"http://purl.org/dc/terms/\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://purl.org/dc/terms/ \">") .append(currdate).append("</dcterms:created> </didl:DIDLInfo>").append("<didl:Item id=\"") .append("uuid-" + UUIDFactory.generateUUID().toString() + "\">"); metadata.append("<didl:Descriptor>").append("<didl:Statement mimeType=\"application/xml; charset=utf-8\">") .append("<dii:Identifier xmlns:dii=\"urn:mpeg:mpeg21:2002:01-DII-NS\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"urn:mpeg:mpeg21:2002:01-DII-NS http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-21_schema_files/dii/dii.xsd\">") .append("urn:hdl:").append(itemhandle).append("</dii:Identifier>").append("</didl:Statement>") .append("</didl:Descriptor>"); metadata.append("<didl:Descriptor>").append("<didl:Statement mimeType=\"application/xml; charset=utf-8\">"); // delegate the metadata section to another crosswalk metadata.append(metadataCrosswalk.createMetadata(nativeItem)); metadata.append("</didl:Statement>").append("</didl:Descriptor>"); /**putfirst item here**/ //**CYCLE HERE!!!!**// try { Bundle[] bundles = item.getBundles("ORIGINAL"); if (bundles.length != 0) { /**cycle bundles**/ for (int i = 0; i < bundles.length; i++) { int flag = 0; Bitstream[] bitstreams = bundles[i].getBitstreams(); /**cycle bitstreams**/ for (int k = 0; k < bitstreams.length; k++) { // Skip internal types if (!bitstreams[k].getFormat().isInternal()) { if (flag == 0) { flag = 1; } metadata.append("<didl:Component id=" + "\"uuid-" + UUIDFactory.generateUUID().toString() + "\">"); if (bitstreams[k].getSize() > maxsize) { metadata.append( "<didl:Resource ref=\"" + ConfigurationManager.getProperty("dspace.url") + "/bitstream/" + itemhandle + "/" + bitstreams[k].getSequenceID() + "/" + bitstreams[k].getName()); metadata.append("\" mimeType=\""); metadata.append(bitstreams[k].getFormat().getMIMEType()); metadata.append("\">"); metadata.append("</didl:Resource>"); } else { try { metadata.append("<didl:Resource mimeType=\""); metadata.append(bitstreams[k].getFormat().getMIMEType()); metadata.append("\" encoding=\"base64\">"); /* * Assume that size of in-line bitstreams will always be * smaller than MAXINT bytes */ int intSize = (int) bitstreams[k].getSize(); byte[] buffer = new byte[intSize]; Context contextl = new Context(); InputStream is = BitstreamStorageManager.retrieve(contextl, bitstreams[k].getID()); BufferedInputStream bis = new BufferedInputStream(is); try { bis.read(buffer); } finally { if (bis != null) { try { bis.close(); } catch (IOException ioe) { } } if (is != null) { try { is.close(); } catch (IOException ioe) { } } } contextl.complete(); String encoding = new String(Base64.encodeBase64(buffer), "ASCII"); metadata.append(encoding); } catch (Exception ex) { log.error("Error creating resource didl", ex); metadata.append("<didl:Resource ref=\"") .append(ConfigurationManager.getProperty("dspace.url")) .append("/bitstream/").append(itemhandle).append("/") .append(bitstreams[k].getSequenceID()).append("/") .append(bitstreams[k].getName()); metadata.append("\" mimeType=\""); metadata.append(bitstreams[k].getFormat().getMIMEType()); metadata.append("\">"); } metadata.append("</didl:Resource>"); } metadata.append("</didl:Component>"); } /*end bitstream cycle*/ } /*end bundle cycle*/ } } } catch (SQLException sqle) { System.err.println("Caught exception:" + sqle.getCause()); log.error("Database error", sqle); } //**END CYCLE HERE **// metadata.append("</didl:Item>").append("</didl:DIDL>"); return metadata.toString(); } }