Java tutorial
/* See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * Esri Inc. 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. */ package com.esri.gpt.server.assertion.index; import com.esri.gpt.catalog.lucene.LuceneIndexAdapter; import com.esri.gpt.framework.context.RequestContext; import com.esri.gpt.server.assertion.components.AsnContext; import java.io.File; import java.io.IOException; import java.util.HashMap; import java.util.Map; import java.util.logging.Level; import java.util.logging.Logger; import org.apache.lucene.analysis.Analyzer; import org.apache.lucene.index.CorruptIndexException; import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.store.Directory; import org.apache.lucene.store.FSDirectory; import org.apache.lucene.store.LockObtainFailedException; import org.apache.lucene.store.NativeFSLockFactory; /** * Base class for an adapter that handles read/write operations against a * Lucene index of assertions. */ public class AsnBaseIndexAdapter { /** class variables ========================================================= */ /** The Logger. */ private static Logger LOGGER = Logger.getLogger(AsnBaseIndexAdapter.class.getName()); /** Hold NativeFSLockFactory objects statically within the JVM */ private static final Map<String, NativeFSLockFactory> NATIVEFSLOCKFACTORIES = new HashMap<String, NativeFSLockFactory>(); /** instance variables ====================================================== */ private AsnIndexReference indexReference; /** constructors ============================================================ */ /** Default constructor */ public AsnBaseIndexAdapter() { } /** properties ============================================================== */ /** * Gets the configuration reference for the index. * @return the index configuration reference */ public AsnIndexReference getIndexReference() { return this.indexReference; } /** * Sets the configuration reference for the index. * @param indexReference index configuration reference */ public void setIndexReference(AsnIndexReference indexReference) { this.indexReference = indexReference; } /** methods ================================================================= */ /** * Closes an index reader. * @param reader the reader to close */ public void closeReader(IndexReader reader) { if (reader != null) { try { reader.close(); } catch (IOException e) { LOGGER.log(Level.SEVERE, "IndexReader failed to close.", e); } } } /** * Closes an index searcher. * @param searcher the searcher to close */ public void closeSearcher(IndexSearcher searcher) { if (searcher != null) { try { searcher.close(); } catch (IOException e) { LOGGER.log(Level.SEVERE, "IndexSearcher failed to close.", e); } } } /** * Closes an index writer. * @param writer the writer to close */ public void closeWriter(IndexWriter writer) { if (writer != null) { try { writer.close(); } catch (CorruptIndexException e) { LOGGER.log(Level.SEVERE, "IndexWriter failed to close.", e); } catch (IOException e) { LOGGER.log(Level.SEVERE, "IndexWriter failed to close.", e); } } } /** * Configures the adapter from an index configuration reference. * @param indexReference index configuration reference */ public void configure(AsnIndexReference indexReference) { this.setIndexReference(indexReference); } /** * Gets the Lucene Directory assoctated with the index. * @return the directory * @throws IOException if an I/O exception occurs */ protected Directory getDirectory() throws IOException { File fDir = new File(this.getIndexReference().getIndexLocation()); NativeFSLockFactory nativeLockFactory = this.getNativeLockFactory(); if (nativeLockFactory != null) { return FSDirectory.open(fDir, nativeLockFactory); } else { return FSDirectory.open(fDir); } } /** * Gets the native lock factory if it has been configured for use. * @return the native lock factory (null if not configured for use) * @throws IOException if an I/O exception occurs */ protected synchronized NativeFSLockFactory getNativeLockFactory() throws IOException { NativeFSLockFactory factory = null; if (this.getIndexReference().getUseNativeFSLockFactory()) { File dir = new File(this.getIndexReference().getIndexLocation()); String path = dir.getCanonicalPath(); synchronized (NATIVEFSLOCKFACTORIES) { factory = NATIVEFSLOCKFACTORIES.get(path); if (factory == null) { factory = new NativeFSLockFactory(dir); NATIVEFSLOCKFACTORIES.put(path, factory); } } } return factory; } /** * Makes an index reader. * <br/>The reader must be closed following use. * @return the reader * @throws CorruptIndexException if the index is corrupt * @throws IOException if an I/O exception occurs */ public IndexReader makeIndexReader() throws CorruptIndexException, IOException { IndexReader reader = IndexReader.open(this.getDirectory(), true); return reader; } /** * Makes an index writer. * <br/>The writer must be closed following use. * @param analyzer the analyzer * @return the writer * @throws CorruptIndexException if the index is corrupt * @throws LockObtainFailedException if a write lock cannot be obtained * @throws IOException if an I/O exception occurs */ public IndexWriter makeIndexWriter(Analyzer analyzer) throws CorruptIndexException, LockObtainFailedException, IOException { IndexWriter.MaxFieldLength mfl = IndexWriter.MaxFieldLength.UNLIMITED; return new IndexWriter(this.getDirectory(), analyzer, mfl); } /** * Instantiates a new analyzer. * @param context the assertion operation context * @return the analyzer */ public Analyzer newAnalyzer(AsnContext context) { RequestContext rc = null; try { LuceneIndexAdapter adapter = null; if ((context != null) && (context.getRequestContext() != null)) { adapter = new LuceneIndexAdapter(context.getRequestContext()); } else { rc = RequestContext.extract(null); adapter = new LuceneIndexAdapter(rc); } return adapter.newAnalyzer(); } finally { if (rc != null) rc.getConnectionBroker().closeAll(); } } /** * Optimizes the index. * @throws CorruptIndexException if the index is corrupt * @throws LockObtainFailedException if a write lock cannot be obtained * @throws IOException if an I/O exception occurs */ public void optimize() throws CorruptIndexException, LockObtainFailedException, IOException { IndexWriter writer = null; try { writer = this.makeIndexWriter(this.newAnalyzer(null)); writer.optimize(); } finally { this.closeWriter(writer); } } /** * Opens and closes a writer. * <br/>This ensures that a directory folder structure exists. * @throws CorruptIndexException if the index is corrupt * @throws LockObtainFailedException if a write lock cannot be obtained * @throws IOException if an I/O exception occurs */ public void touch() throws CorruptIndexException, LockObtainFailedException, IOException { IndexWriter writer = null; try { writer = this.makeIndexWriter(this.newAnalyzer(null)); } finally { closeWriter(writer); } } }