Java tutorial
package org.apache.maven.indexer.examples; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. */ import org.apache.lucene.document.Document; import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.MultiFields; import org.apache.lucene.search.BooleanClause.Occur; import org.apache.lucene.search.BooleanQuery; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.util.Bits; import org.apache.maven.index.ArtifactInfo; import org.apache.maven.index.ArtifactInfoFilter; import org.apache.maven.index.ArtifactInfoGroup; import org.apache.maven.index.Field; import org.apache.maven.index.FlatSearchRequest; import org.apache.maven.index.FlatSearchResponse; import org.apache.maven.index.GroupedSearchRequest; import org.apache.maven.index.GroupedSearchResponse; import org.apache.maven.index.Grouping; import org.apache.maven.index.Indexer; import org.apache.maven.index.IteratorSearchRequest; import org.apache.maven.index.IteratorSearchResponse; import org.apache.maven.index.MAVEN; import org.apache.maven.index.context.IndexCreator; import org.apache.maven.index.context.IndexUtils; import org.apache.maven.index.context.IndexingContext; import org.apache.maven.index.expr.SourcedSearchExpression; import org.apache.maven.index.expr.UserInputSearchExpression; import org.apache.maven.index.search.grouping.GAGrouping; import org.apache.maven.index.updater.IndexUpdateRequest; import org.apache.maven.index.updater.IndexUpdateResult; import org.apache.maven.index.updater.IndexUpdater; import org.apache.maven.index.updater.ResourceFetcher; import org.apache.maven.index.updater.WagonHelper; import org.apache.maven.wagon.Wagon; import org.apache.maven.wagon.events.TransferEvent; import org.apache.maven.wagon.events.TransferListener; import org.apache.maven.wagon.observers.AbstractTransferListener; import org.codehaus.plexus.DefaultContainerConfiguration; import org.codehaus.plexus.DefaultPlexusContainer; import org.codehaus.plexus.PlexusConstants; import org.codehaus.plexus.PlexusContainer; import org.codehaus.plexus.PlexusContainerException; import org.codehaus.plexus.component.repository.exception.ComponentLookupException; import org.codehaus.plexus.util.StringUtils; import org.eclipse.aether.util.version.GenericVersionScheme; import org.eclipse.aether.version.InvalidVersionSpecificationException; import org.eclipse.aether.version.Version; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.Date; import java.util.List; import java.util.Map; /** * Collection of some use cases. */ public class BasicUsageExample { public static void main(String[] args) throws Exception { final BasicUsageExample basicUsageExample = new BasicUsageExample(); basicUsageExample.perform(); } // == private final PlexusContainer plexusContainer; private final Indexer indexer; private final IndexUpdater indexUpdater; private final Wagon httpWagon; private IndexingContext centralContext; public BasicUsageExample() throws PlexusContainerException, ComponentLookupException { // here we create Plexus container, the Maven default IoC container // Plexus falls outside of MI scope, just accept the fact that // MI is a Plexus component ;) // If needed more info, ask on Maven Users list or Plexus Users list // google is your friend! final DefaultContainerConfiguration config = new DefaultContainerConfiguration(); config.setClassPathScanning(PlexusConstants.SCANNING_INDEX); this.plexusContainer = new DefaultPlexusContainer(config); // lookup the indexer components from plexus this.indexer = plexusContainer.lookup(Indexer.class); this.indexUpdater = plexusContainer.lookup(IndexUpdater.class); // lookup wagon used to remotely fetch index this.httpWagon = plexusContainer.lookup(Wagon.class, "http"); } public void perform() throws IOException, ComponentLookupException, InvalidVersionSpecificationException { // Files where local cache is (if any) and Lucene Index should be located File centralLocalCache = new File("target/central-cache"); File centralIndexDir = new File("target/central-index"); // Creators we want to use (search for fields it defines) List<IndexCreator> indexers = new ArrayList<>(); indexers.add(plexusContainer.lookup(IndexCreator.class, "min")); indexers.add(plexusContainer.lookup(IndexCreator.class, "jarContent")); indexers.add(plexusContainer.lookup(IndexCreator.class, "maven-plugin")); // Create context for central repository index centralContext = indexer.createIndexingContext("central-context", "central", centralLocalCache, centralIndexDir, "http://repo1.maven.org/maven2", null, true, true, indexers); // Update the index (incremental update will happen if this is not 1st run and files are not deleted) // This whole block below should not be executed on every app start, but rather controlled by some configuration // since this block will always emit at least one HTTP GET. Central indexes are updated once a week, but // other index sources might have different index publishing frequency. // Preferred frequency is once a week. if (true) { System.out.println("Updating Index..."); System.out.println("This might take a while on first run, so please be patient!"); // Create ResourceFetcher implementation to be used with IndexUpdateRequest // Here, we use Wagon based one as shorthand, but all we need is a ResourceFetcher implementation TransferListener listener = new AbstractTransferListener() { public void transferStarted(TransferEvent transferEvent) { System.out.print(" Downloading " + transferEvent.getResource().getName()); } public void transferProgress(TransferEvent transferEvent, byte[] buffer, int length) { } public void transferCompleted(TransferEvent transferEvent) { System.out.println(" - Done"); } }; ResourceFetcher resourceFetcher = new WagonHelper.WagonFetcher(httpWagon, listener, null, null); Date centralContextCurrentTimestamp = centralContext.getTimestamp(); IndexUpdateRequest updateRequest = new IndexUpdateRequest(centralContext, resourceFetcher); IndexUpdateResult updateResult = indexUpdater.fetchAndUpdateIndex(updateRequest); if (updateResult.isFullUpdate()) { System.out.println("Full update happened!"); } else if (updateResult.getTimestamp().equals(centralContextCurrentTimestamp)) { System.out.println("No update needed, index is up to date!"); } else { System.out.println("Incremental update happened, change covered " + centralContextCurrentTimestamp + " - " + updateResult.getTimestamp() + " period."); } System.out.println(); } System.out.println(); System.out.println("Using index"); System.out.println("==========="); System.out.println(); // ==== // Case: // dump all the GAVs // NOTE: will not actually execute do this below, is too long to do (Central is HUGE), but is here as code // example if (false) { final IndexSearcher searcher = centralContext.acquireIndexSearcher(); try { final IndexReader ir = searcher.getIndexReader(); Bits liveDocs = MultiFields.getLiveDocs(ir); for (int i = 0; i < ir.maxDoc(); i++) { if (liveDocs == null || liveDocs.get(i)) { final Document doc = ir.document(i); final ArtifactInfo ai = IndexUtils.constructArtifactInfo(doc, centralContext); System.out.println(ai.getGroupId() + ":" + ai.getArtifactId() + ":" + ai.getVersion() + ":" + ai.getClassifier() + " (sha1=" + ai.getSha1() + ")"); } } } finally { centralContext.releaseIndexSearcher(searcher); } } // ==== // Case: // Search for all GAVs with known G and A and having version greater than V final GenericVersionScheme versionScheme = new GenericVersionScheme(); final String versionString = "1.5.0"; final Version version = versionScheme.parseVersion(versionString); // construct the query for known GA final Query groupIdQ = indexer.constructQuery(MAVEN.GROUP_ID, new SourcedSearchExpression("org.sonatype.nexus")); final Query artifactIdQ = indexer.constructQuery(MAVEN.ARTIFACT_ID, new SourcedSearchExpression("nexus-api")); final BooleanQuery query = new BooleanQuery(); query.add(groupIdQ, Occur.MUST); query.add(artifactIdQ, Occur.MUST); // we want "jar" artifacts only query.add(indexer.constructQuery(MAVEN.PACKAGING, new SourcedSearchExpression("jar")), Occur.MUST); // we want main artifacts only (no classifier) // Note: this below is unfinished API, needs fixing query.add(indexer.constructQuery(MAVEN.CLASSIFIER, new SourcedSearchExpression(Field.NOT_PRESENT)), Occur.MUST_NOT); // construct the filter to express "V greater than" final ArtifactInfoFilter versionFilter = new ArtifactInfoFilter() { public boolean accepts(final IndexingContext ctx, final ArtifactInfo ai) { try { final Version aiV = versionScheme.parseVersion(ai.getVersion()); // Use ">=" if you are INCLUSIVE return aiV.compareTo(version) > 0; } catch (InvalidVersionSpecificationException e) { // do something here? be safe and include? return true; } } }; System.out.println( "Searching for all GAVs with G=org.sonatype.nexus and nexus-api and having V greater than 1.5.0"); final IteratorSearchRequest request = new IteratorSearchRequest(query, Collections.singletonList(centralContext), versionFilter); final IteratorSearchResponse response = indexer.searchIterator(request); for (ArtifactInfo ai : response) { System.out.println(ai.toString()); } // Case: // Use index // Searching for some artifact Query gidQ = indexer.constructQuery(MAVEN.GROUP_ID, new SourcedSearchExpression("org.apache.maven.indexer")); Query aidQ = indexer.constructQuery(MAVEN.ARTIFACT_ID, new SourcedSearchExpression("indexer-artifact")); BooleanQuery bq = new BooleanQuery(); bq.add(gidQ, Occur.MUST); bq.add(aidQ, Occur.MUST); searchAndDump(indexer, "all artifacts under GA org.apache.maven.indexer:indexer-artifact", bq); // Searching for some main artifact bq = new BooleanQuery(); bq.add(gidQ, Occur.MUST); bq.add(aidQ, Occur.MUST); // bq.add( nexusIndexer.constructQuery( MAVEN.CLASSIFIER, new SourcedSearchExpression( "*" ) ), Occur.MUST_NOT // ); searchAndDump(indexer, "main artifacts under GA org.apache.maven.indexer:indexer-artifact", bq); // doing sha1 search searchAndDump(indexer, "SHA1 7ab67e6b20e5332a7fb4fdf2f019aec4275846c2", indexer.constructQuery(MAVEN.SHA1, new SourcedSearchExpression("7ab67e6b20e5332a7fb4fdf2f019aec4275846c2"))); searchAndDump(indexer, "SHA1 7ab67e6b20 (partial hash)", indexer.constructQuery(MAVEN.SHA1, new UserInputSearchExpression("7ab67e6b20"))); // doing classname search (incomplete classname) searchAndDump(indexer, "classname DefaultNexusIndexer (note: Central does not publish classes in the index)", indexer.constructQuery(MAVEN.CLASSNAMES, new UserInputSearchExpression("DefaultNexusIndexer"))); // doing search for all "canonical" maven plugins latest versions bq = new BooleanQuery(); bq.add(indexer.constructQuery(MAVEN.PACKAGING, new SourcedSearchExpression("maven-plugin")), Occur.MUST); bq.add(indexer.constructQuery(MAVEN.GROUP_ID, new SourcedSearchExpression("org.apache.maven.plugins")), Occur.MUST); searchGroupedAndDump(indexer, "all \"canonical\" maven plugins", bq, new GAGrouping()); // doing search for all archetypes latest versions searchGroupedAndDump(indexer, "all maven archetypes (latest versions)", indexer.constructQuery(MAVEN.PACKAGING, new SourcedSearchExpression("maven-archetype")), new GAGrouping()); // close cleanly indexer.closeIndexingContext(centralContext, false); } public void searchAndDump(Indexer nexusIndexer, String descr, Query q) throws IOException { System.out.println("Searching for " + descr); FlatSearchResponse response = nexusIndexer.searchFlat(new FlatSearchRequest(q, centralContext)); for (ArtifactInfo ai : response.getResults()) { System.out.println(ai.toString()); } System.out.println("------"); System.out.println("Total: " + response.getTotalHitsCount()); System.out.println(); } private static final int MAX_WIDTH = 60; public void searchGroupedAndDump(Indexer nexusIndexer, String descr, Query q, Grouping g) throws IOException { System.out.println("Searching for " + descr); GroupedSearchResponse response = nexusIndexer.searchGrouped(new GroupedSearchRequest(q, g, centralContext)); for (Map.Entry<String, ArtifactInfoGroup> entry : response.getResults().entrySet()) { ArtifactInfo ai = entry.getValue().getArtifactInfos().iterator().next(); System.out.println("* Entry " + ai); System.out.println(" Latest version: " + ai.getVersion()); System.out.println(StringUtils.isBlank(ai.getDescription()) ? "No description in plugin's POM." : StringUtils.abbreviate(ai.getDescription(), MAX_WIDTH)); System.out.println(); } System.out.println("------"); System.out.println("Total record hits: " + response.getTotalHitsCount()); System.out.println(); } }