Java tutorial
/* * 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. */ package org.apache.jackrabbit.oak.plugins.index.lucene.directory; import java.io.File; import java.io.IOException; import org.apache.commons.io.FileUtils; import static com.google.common.base.Preconditions.checkState; import static org.apache.jackrabbit.oak.plugins.index.lucene.directory.IndexRootDirectory.INDEX_METADATA_FILE_NAME; public final class LocalIndexDir implements Comparable<LocalIndexDir> { final File dir; final IndexMeta indexMeta; public LocalIndexDir(File dir) throws IOException { this.dir = dir.getCanonicalFile(); File indexDetails = new File(dir, IndexRootDirectory.INDEX_METADATA_FILE_NAME); checkState(isIndexDir(dir), "No file [%s] found in dir [%s]", INDEX_METADATA_FILE_NAME, dir.getAbsolutePath()); this.indexMeta = new IndexMeta(indexDetails); } public long size() { return FileUtils.sizeOfDirectory(dir); } public boolean isEmpty() { String[] listing = dir.list(); //If some IO error occurs listing would be null //In such a case better to return false if (listing == null) { return false; } //If the dir only has the meta file then it would be //considered as empty return listing.length == 1; } public String getJcrPath() { return indexMeta.indexPath; } public String getFSPath() { return dir.getAbsolutePath(); } @Override public int compareTo(LocalIndexDir o) { return indexMeta.compareTo(o.indexMeta); } @Override public String toString() { return String.format("%s (%s)", dir.getAbsolutePath(), indexMeta); } static boolean isIndexDir(File file) { File indexDetails = new File(file, IndexRootDirectory.INDEX_METADATA_FILE_NAME); return indexDetails.exists(); } }