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.drill.exec.util; import org.apache.drill.shaded.guava.com.google.common.base.Strings; import org.apache.drill.shaded.guava.com.google.common.io.Files; import org.apache.commons.io.FileUtils; import org.apache.drill.exec.ExecTest; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.junit.BeforeClass; import java.io.File; import java.io.IOException; import java.util.Arrays; /** * Base test class for file system util classes that will during test initialization * setup file system connection and create directories and files needed for unit tests. */ public class FileSystemUtilTestBase { /* Directory and file structure created during test initialization: ../a ../a/f.txt ../a/.f.txt ../a/_f.txt ../a/aa ../a/aa/f.txt ../a/aa/.f.txt ../a/aa/_f.txt ../b ../b/f.txt ../b/.f.txt ../b/_f.txt ../.a ../.a/f.txt ../_a ../_a/f.txt */ protected static FileSystem fs; protected static Path base; @BeforeClass public static void setup() throws IOException { // initialize file system fs = ExecTest.getLocalFileSystem(); // create temporary directory with sub-folders and files final File tempDir = Files.createTempDir(); Runtime.getRuntime().addShutdownHook(new Thread(() -> FileUtils.deleteQuietly(tempDir))); base = new Path(tempDir.toURI().getPath()); createDefaultStructure(fs, base, "a", 2); createDefaultStructure(fs, base, "b", 1); // create hidden directory with file Path hiddenDirectory = new Path(base, ".a"); fs.mkdirs(hiddenDirectory); fs.createNewFile(new Path(hiddenDirectory, "f.txt")); // create underscore directory with file Path underscoreDirectory = new Path(base, "_a"); fs.mkdirs(underscoreDirectory); fs.createNewFile(new Path(underscoreDirectory, "f.txt")); } private static void createDefaultStructure(FileSystem fs, Path base, String name, int nesting) throws IOException { Path newBase = base; for (int i = 1; i <= nesting; i++) { Path path = new Path(newBase, Strings.repeat(name, i)); fs.mkdirs(path); for (String fileName : Arrays.asList("f.txt", ".f.txt", "_f.txt")) { fs.createNewFile(new Path(path, fileName)); } newBase = path; } } }