Java tutorial
/* * Copyright 2014 Johns Hopkins University * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.dataconservancy.packaging.tool.impl; import java.io.File; import java.io.IOException; import java.net.URI; import java.net.URISyntaxException; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.http.client.utils.URIBuilder; import org.dataconservancy.packaging.tool.api.PackageDescriptionCreator; import org.dataconservancy.packaging.tool.api.PackageDescriptionCreatorException; import org.dataconservancy.packaging.tool.impl.rules.FileContext; import org.dataconservancy.packaging.tool.impl.rules.FileContextImpl; import org.dataconservancy.packaging.tool.impl.rules.Mapping; import org.dataconservancy.packaging.tool.impl.rules.Rule; import org.dataconservancy.packaging.tool.impl.rules.RuleImpl; import org.dataconservancy.packaging.tool.model.PackageArtifact; import org.dataconservancy.packaging.tool.model.PackageDescription; import org.dataconservancy.packaging.tool.model.PackageRelationship; import org.dataconservancy.packaging.tool.model.description.Action; import org.dataconservancy.packaging.tool.model.description.RuleSpec; import org.dataconservancy.packaging.tool.model.description.RulesSpec; public class GeneralPackageDescriptionCreator implements PackageDescriptionCreator { private final List<Rule> rules = new ArrayList<>(); private Set<String> visitedFiles = new HashSet<>(); public GeneralPackageDescriptionCreator(RulesSpec rulesSpec) { for (RuleSpec ruleSpec : rulesSpec.getRule()) { rules.add(new RuleImpl(ruleSpec)); } } @Override public PackageDescription createPackageDescription(String packageOntologyIdentifier, File directoryTreeRoot) throws PackageDescriptionCreatorException { if (directoryTreeRoot == null) { throw new PackageDescriptionCreatorException("The provided directory is null."); } else if (!directoryTreeRoot.exists()) { throw new PackageDescriptionCreatorException( "The directory specified by file path \'" + directoryTreeRoot.getPath() + "\' does not exist"); } else if (!directoryTreeRoot.canRead()) { throw new PackageDescriptionCreatorException("The specified directory cannot be read."); } if (packageOntologyIdentifier == null) { throw new PackageDescriptionCreatorException("The package ontology specification must not be null."); } visitedFiles.clear(); /* * make sure we have a clear file Set before we * start */ PackageDescription desc = new PackageDescription(); Map<String, PackageArtifact> artifacts = new HashMap<>(); visitFile(new FileContextImpl(directoryTreeRoot, directoryTreeRoot, false), artifacts); desc.setPackageArtifacts(new HashSet<>(artifacts.values())); desc.setRootArtifactRef(directoryTreeRoot.toURI().toString()); desc.setPackageOntologyIdentifier(packageOntologyIdentifier); return desc; } private void visitFile(FileContext cxt, Map<String, PackageArtifact> artifacts) throws PackageDescriptionCreatorException { try { String path = cxt.getFile().getCanonicalPath(); if (visitedFiles.contains(path)) { if (Files.isSymbolicLink(cxt.getFile().toPath())) { throw new PackageDescriptionCreatorException("Symbolic link cycle detected", "Fix offending symbolic link at " + cxt.getFile().toString() + ", which points to " + path); } else { throw new PackageDescriptionCreatorException("Symbolic link cycle detected", "There is a symbolic link under " + cxt.getRoot().toString() + " which points to " + path + ". Find the link and remove it."); } } else { visitedFiles.add(path); } } catch (IOException e) { throw new PackageDescriptionCreatorException("Error determining canonical path of " + cxt.getFile(), e); } try { for (Rule rule : rules) { if (rule.select(cxt)) { if (Action.EXCLUDE.equals(rule.getAction())) { cxt.setIgnored(true); continue; } else if (Action.INCLUDE.equals(rule.getAction())) { populate(cxt, rule, artifacts); } break; } } } catch (Exception e) { throw new PackageDescriptionCreatorException( "Error applying package description generation rules to pathname " + cxt.getFile().toString() + ": \n" + e.getMessage(), e); } if (cxt.getFile().isDirectory()) { for (File child : cxt.getFile().listFiles()) { //To support the cancelling of package description creation we check here to see if the thread has been interrupted. if (Thread.currentThread().isInterrupted()) { break; } visitFile(new FileContextImpl(child, cxt.getRoot(), cxt.isIgnored()), artifacts); } } } /* * Create PakageArtifact from the file, populate PackageDescription with it */ private void populate(FileContext cxt, Rule rule, Map<String, PackageArtifact> artifacts) { List<Mapping> mappings = rule.getMappings(cxt); for (Mapping mapping : mappings) { /* We are using file URI as artifact IDs, unless multiple mappings */ URIBuilder urib = new URIBuilder(cxt.getFile().toURI()); //String id = cxt.getFile().toURI().toString(); /* * If multiple mappings implicated by this file, then make sure * they're differentiated */ if (mappings.size() > 1) { String specifier = mapping.getSpecifier(); if (specifier != null) { urib.setFragment(specifier); } } URI uri = null; try { uri = urib.build(); } catch (URISyntaxException e) { } String id = uri.toString(); PackageArtifact artifact = new PackageArtifact(); artifacts.put(id, artifact); artifact.setId(id); artifact.setIgnored(cxt.isIgnored()); //we need to relativize against the content root if one exists, not the supplied root artifact dir if (cxt.getRoot().getParentFile() != null) { Path rootPath = Paths.get(cxt.getRoot().getParentFile().getPath()); Path filePath = Paths.get(cxt.getFile().getPath()); artifact.setArtifactRef(String.valueOf(rootPath.relativize(filePath))); } else { Path filePath = Paths.get(cxt.getFile().getPath()); artifact.setArtifactRef(String.valueOf(filePath)); } if (uri.getFragment() != null) { artifact.getArtifactRef().setFragment(uri.getFragment()); } /* * if file is a normal file, set the isByteStream flag to true on * PackageArtifact */ if (cxt.getFile().isFile()) { artifact.setByteStream(true); } artifact.setType(mapping.getType().getValue()); if (mapping.getType().isByteStream() != null) { artifact.setByteStream(mapping.getType().isByteStream()); } else { artifact.setByteStream(cxt.getFile().isFile()); } for (Map.Entry<String, List<String>> entry : mapping.getProperties().entrySet()) { Set<String> valueSet = new HashSet<>(entry.getValue()); artifact.setSimplePropertyValues(entry.getKey(), valueSet); } /* * Since we use file URI as artifact IDs (with optional specifier as * URI fragment), we just need to use the relationship's target * file's URI as the relationship target, and we're done!. */ List<PackageRelationship> rels = new ArrayList<>(); for (Map.Entry<String, Set<URI>> rel : mapping.getRelationships().entrySet()) { Set<String> relTargets = new HashSet<>(); for (URI target : rel.getValue()) { relTargets.add(target.toString()); } rels.add(new PackageRelationship(rel.getKey(), true, relTargets)); } artifact.setRelationships(rels); } } }