Java tutorial
/** * The contents of this file are subject to the license and copyright * detailed in the LICENSE file at the root of the source * tree and available online at * * https://github.com/keeps/roda */ package org.roda.core.plugins.misc; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.stream.Stream; import org.apache.commons.io.FilenameUtils; import org.roda.core.storage.fs.FSUtils; import org.roda_project.commons_ip.model.AIP; import org.roda_project.commons_ip.model.IPContentType; import org.roda_project.commons_ip.model.IPDescriptiveMetadata; import org.roda_project.commons_ip.model.IPFile; import org.roda_project.commons_ip.model.IPMetadata; import org.roda_project.commons_ip.model.IPRepresentation; import org.roda_project.commons_ip.model.MetadataType; import org.roda_project.commons_ip.model.ParseException; import org.roda_project.commons_ip.model.RepresentationContentType; import org.roda_project.commons_ip.model.RepresentationStatus; import org.roda_project.commons_ip.model.impl.AIPWrap; import org.roda_project.commons_ip.model.impl.BasicAIP; import org.roda_project.commons_ip.utils.IPException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; /** * {@link AIP} implementation that can read a RODA AIP from a folder. * * @author Rui Castro (rui.castro@gmail.com) */ final class RodaFolderAIP extends AIPWrap { /** * Logger. */ private static final Logger LOGGER = LoggerFactory.getLogger(RodaFolderAIP.class); /** * Constant string "id". */ private static final String ID = "id"; /** * Constant string "type". */ private static final String TYPE = "type"; /** * Constant string "version". */ private static final String VERSION = "version"; /** * Constant string "representations". */ private static final String REPRESENTATIONS = "representations"; /** * Constant string "metadata". */ private static final String METADATA = "metadata"; /** * Constant string "descriptive". */ private static final String DESCRIPTIVE = "descriptive"; /** * Constant string "descriptiveMetadata". */ private static final String DESCRIPTIVE_METADATA = "descriptiveMetadata"; /** * Constant string "preservation". */ private static final String PRESERVATION = "preservation"; /** * Constant string "other". */ private static final String OTHER = "other"; /** * Constant string "schemas". */ private static final String SCHEMAS = "schemas"; /** * Constant string "documentation". */ private static final String DOCUMENTATION = "documentation"; /** * Constant string "submission". */ private static final String SUBMISSION = "submission"; /** * Constructor. * * @param aip * the {@link AIP} to wrap. * @param path * AIP path. */ private RodaFolderAIP(final AIP aip, final Path path) { super(aip); setBasePath(path); } /** * Reads a {@link RodaFolderAIP} from the given folder. * * @param source * the source folder. * @return a {@link RodaFolderAIP}. * @throws ParseException * if some error occurs. */ static AIP parse(final Path source) throws ParseException { return new RodaFolderAIP(new BasicAIP(), source).read(); } /** * Read the AIP. * * @return the {@link AIP}. * @throws ParseException * if some error occurred. */ private AIP read() throws ParseException { try { final ObjectMapper mapper = new ObjectMapper(); final JsonNode json = mapper.readTree(getBasePath().resolve("aip.json").toFile()); this.setId(getBasePath().getFileName().toString()); if (json.has("parentId")) { this.setAncestors(Collections.singletonList(json.get("parentId").asText())); } this.setContentType(new IPContentType(json.get(TYPE).asText())); this.setState(json.get("state").asText()); final Path mdPath = getBasePath().resolve(METADATA); readJsonDescriptiveMDs(this, json); findAndAddPreservationMDs(this::addPreservationMetadata); findAndAddOtherMDs(mdPath.resolve(OTHER), this::addOtherMetadata); findIPFiles(getBasePath().resolve(SCHEMAS)).forEach(this::addSchema); findIPFiles(getBasePath().resolve(DOCUMENTATION)).forEach(this::addDocumentation); findIPFiles(getBasePath().resolve(SUBMISSION)).forEach(this::addSubmission); readRepresentations(this, json); return this; } catch (final IOException | IPException e) { LOGGER.debug("Error reading aip.json", e); throw new ParseException("Error reading aip.json", e); } } /** * Read {@link IPRepresentation} and update the {@link AIP}. * * @param aip * the {@link AIP}. * @param json * the JSON node. * @throws IPException * if some error occurs. * @throws IOException * if some I/O error occurs. */ private void readRepresentations(final AIP aip, final JsonNode json) throws IPException, IOException { if (json.has(REPRESENTATIONS)) { final Iterator<JsonNode> iterator = json.get(REPRESENTATIONS).elements(); while (iterator.hasNext()) { aip.addRepresentation(readRepresentation(iterator.next())); } } } /** * Read {@link IPRepresentation}. * * @param json * the JSON node. * @return the {@link IPRepresentation}. * @throws IOException * if some I/O error occurs. * @throws IPException * if some error occured. */ private IPRepresentation readRepresentation(final JsonNode json) throws IOException, IPException { final IPRepresentation rep = new IPRepresentation(json.get(ID).asText()); rep.setStatus(json.get("original").asBoolean() ? RepresentationStatus.getORIGINAL() : RepresentationStatus.getOTHER()); rep.setContentType(new RepresentationContentType(json.get(TYPE).asText())); final Path repPath = getBasePath().resolve(REPRESENTATIONS).resolve(rep.getRepresentationID()); final Path mdPath = repPath.resolve(METADATA); findIPFiles(repPath.resolve("data")).forEach(rep::addFile); findDescriptiveMDs(mdPath.resolve(DESCRIPTIVE)).forEach(rep::addDescriptiveMetadata); findPreservationMDs(mdPath.resolve(PRESERVATION)).forEach(rep::addPreservationMetadata); findAndAddOtherMDs(mdPath.resolve(OTHER), rep::addOtherMetadata); // TODO: ask for example of representation agents findIPFiles(repPath.resolve(SCHEMAS)).forEach(rep::addDocumentation); findIPFiles(repPath.resolve(DOCUMENTATION)).forEach(rep::addDocumentation); return rep; } /** * Read {@link IPDescriptiveMetadata} records from <code>aip.json</code> * "descriptiveMetadata" field and update the {@link AIP}. * * @param aip * the {@link AIP}. * @param json * the JSON node. * @throws IPException * if some error occurs. */ private void readJsonDescriptiveMDs(final AIP aip, final JsonNode json) throws IPException { if (json.has(DESCRIPTIVE_METADATA)) { final Iterator<JsonNode> iterator = json.get(DESCRIPTIVE_METADATA).elements(); while (iterator.hasNext()) { aip.addDescriptiveMetadata(readJsonDescriptionMD(iterator.next())); } } } /** * Read {@link IPDescriptiveMetadata} from a {@link JsonNode}. * * @param json * the JSON node. * @return the {@link IPDescriptiveMetadata}. */ private IPDescriptiveMetadata readJsonDescriptionMD(final JsonNode json) { final String id = json.get(ID).asText(); final String version = json.has(VERSION) ? json.get(VERSION).asText() : null; return new IPDescriptiveMetadata(id, new IPFile(getBasePath().resolve(METADATA).resolve(DESCRIPTIVE).resolve(id)), new MetadataType(json.get(TYPE).asText()), version); } /** * Find preservation metadata files and adds them to {@link AIP}. * * @param mdSetter * the {@link IPMetadataSetter}. * @throws IOException * if some I/O error occurs. * @throws IPException * if some other error occurs. */ private void findAndAddPreservationMDs(final IPMetadataSetter mdSetter) throws IOException, IPException { for (IPMetadata md : findPreservationMDs(getBasePath().resolve(METADATA).resolve(PRESERVATION))) { mdSetter.addMetadata(md); } } /** * Find other metadata files and for each one calls * {@link IPMetadataSetter#addMetadata(IPMetadata)}. * * @param omdPath * the {@link Path} to other metadata files. * @param mdSetter * the {@link IPMetadataSetter}. * @throws IOException * if some I/O error occurs. * @throws IPException * if some other error occurs. */ private void findAndAddOtherMDs(final Path omdPath, final IPMetadataSetter mdSetter) throws IOException, IPException { if (FSUtils.isDirectory(omdPath)) { final Iterator<Path> paths = Files.list(omdPath).iterator(); while (paths.hasNext()) { final Path mdPath = paths.next(); if (FSUtils.isDirectory(mdPath)) { for (IPMetadata md : findMDs(mdPath, MetadataType.OTHER().setOtherType(mdPath.getFileName().toString()))) { mdSetter.addMetadata(md); } } if (FSUtils.isFile(mdPath)) { for (IPMetadata md : findMDs(mdPath, MetadataType.OTHER())) { mdSetter.addMetadata(md); } } } } } /** * Find {@link IPDescriptiveMetadata}s in the given {@link Path}. * * @param dmdPath * the {@link Path}. * @return the {@link List <IPDescriptiveMetadata>}. * @throws IOException * if some I/O error occurs. */ private List<IPDescriptiveMetadata> findDescriptiveMDs(final Path dmdPath) throws IOException { final List<IPDescriptiveMetadata> list = new ArrayList<>(); if (FSUtils.isDirectory(dmdPath)) { try (Stream<Path> paths = Files.walk(dmdPath)) { paths.forEach(filePath -> { if (FSUtils.isFile(filePath)) { list.add(new IPDescriptiveMetadata( FilenameUtils.removeExtension(filePath.getFileName().toString()), new IPFile(filePath), MetadataType.OTHER(), null)); } }); } } return list; } /** * Find {@link IPMetadata}s in the given {@link Path}. * * @param mdPath * the {@link Path}. * @return the {@link List<IPMetadata>}. * @throws IOException * if some I/O error occurs. */ private List<IPMetadata> findPreservationMDs(final Path mdPath) throws IOException { return findMDs(mdPath, new MetadataType(MetadataType.MetadataTypeEnum.PREMIS)); } /** * Find {@link IPMetadata}s in the given {@link Path}. * * @param mdPath * the {@link Path}. * @param mdType * the {@link MetadataType}. * @return the {@link List<IPMetadata>}. * @throws IOException * if some I/O error occurs. */ private List<IPMetadata> findMDs(final Path mdPath, final MetadataType mdType) throws IOException { final List<IPMetadata> list = new ArrayList<>(); if (FSUtils.isDirectory(mdPath)) { try (Stream<Path> paths = Files.walk(mdPath)) { paths.forEach(filePath -> { if (FSUtils.isFile(filePath)) { list.add(new IPMetadata(FilenameUtils.removeExtension(filePath.getFileName().toString()), new IPFile(filePath), mdType)); } }); } } return list; } /** * Find {@link IPFile}s in the given {@link Path}. * * @param filesPath * the {@link Path}. * @return the {@link List<IPFile>}. * @throws IOException * if some I/O error occurs. */ private List<IPFile> findIPFiles(final Path filesPath) throws IOException { final List<IPFile> list = new ArrayList<>(); if (FSUtils.isDirectory(filesPath)) { try (Stream<Path> paths = Files.walk(filesPath)) { paths.forEach(filePath -> { if (FSUtils.isFile(filePath)) { list.add(new IPFile(filePath)); } }); } } return list; } /** * {@link IPMetadata} setter interface. Implementations of this interface * should add the {@link IPMetadata} records to themselves. */ @FunctionalInterface interface IPMetadataSetter { /** * Add the specified metadata. * * @param md * the {@link IPMetadata}. * @throws IPException * if some error occurred. */ void addMetadata(IPMetadata md) throws IPException; } }