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.hadoop.fs; import java.io.DataInputStream; import java.io.IOException; import java.io.FileNotFoundException; import java.util.EnumSet; import org.apache.commons.lang.RandomStringUtils; import org.apache.hadoop.fs.Options.CreateOpts; import org.apache.hadoop.fs.Options.CreateOpts.BlockSize; import org.apache.hadoop.io.IOUtils; import org.apache.hadoop.test.GenericTestUtils; import org.junit.Assert; /** * Helper class for unit tests. */ public final class FileContextTestHelper { private static final int DEFAULT_BLOCK_SIZE = 1024; private static final int DEFAULT_NUM_BLOCKS = 2; private final String testRootDir; private String absTestRootDir = null; /** * Create a context with test root relative to the test directory */ public FileContextTestHelper() { this(GenericTestUtils.getRandomizedTestDir().getAbsolutePath()); } /** * Create a context with the given test root */ public FileContextTestHelper(String testRootDir) { this.testRootDir = testRootDir; } public static int getDefaultBlockSize() { return DEFAULT_BLOCK_SIZE; } public static byte[] getFileData(int numOfBlocks, long blockSize) { byte[] data = new byte[(int) (numOfBlocks * blockSize)]; for (int i = 0; i < data.length; i++) { data[i] = (byte) (i % 10); } return data; } public Path getTestRootPath(FileContext fc) { return fc.makeQualified(new Path(testRootDir)); } public Path getTestRootPath(FileContext fc, String pathString) { return fc.makeQualified(new Path(testRootDir, pathString)); } // the getAbsolutexxx method is needed because the root test dir // can be messed up by changing the working dir. public String getAbsoluteTestRootDir(FileContext fc) { if (absTestRootDir == null) { if (new Path(testRootDir).isAbsolute()) { absTestRootDir = testRootDir; } else { absTestRootDir = fc.getWorkingDirectory().toString() + "/" + testRootDir; } } return absTestRootDir; } public Path getAbsoluteTestRootPath(FileContext fc) { return fc.makeQualified(new Path(getAbsoluteTestRootDir(fc))); } public Path getDefaultWorkingDirectory(FileContext fc) { return getTestRootPath(fc, "/user/" + System.getProperty("user.name")) .makeQualified(fc.getDefaultFileSystem().getUri(), fc.getWorkingDirectory()); } /* * Create files with numBlocks blocks each with block size blockSize. */ public static long createFile(FileContext fc, Path path, int numBlocks, CreateOpts... options) throws IOException { BlockSize blockSizeOpt = CreateOpts.getOpt(CreateOpts.BlockSize.class, options); long blockSize = blockSizeOpt != null ? blockSizeOpt.getValue() : DEFAULT_BLOCK_SIZE; FSDataOutputStream out = fc.create(path, EnumSet.of(CreateFlag.CREATE), options); byte[] data = getFileData(numBlocks, blockSize); out.write(data, 0, data.length); out.close(); return data.length; } public static long createFile(FileContext fc, Path path, int numBlocks, int blockSize) throws IOException { return createFile(fc, path, numBlocks, CreateOpts.blockSize(blockSize), CreateOpts.createParent()); } public static long createFile(FileContext fc, Path path) throws IOException { return createFile(fc, path, DEFAULT_NUM_BLOCKS, CreateOpts.createParent()); } public long createFile(FileContext fc, String name) throws IOException { Path path = getTestRootPath(fc, name); return createFile(fc, path); } public long createFileNonRecursive(FileContext fc, String name) throws IOException { Path path = getTestRootPath(fc, name); return createFileNonRecursive(fc, path); } public static long createFileNonRecursive(FileContext fc, Path path) throws IOException { return createFile(fc, path, DEFAULT_NUM_BLOCKS, CreateOpts.donotCreateParent()); } public static void appendToFile(FileContext fc, Path path, int numBlocks, CreateOpts... options) throws IOException { BlockSize blockSizeOpt = CreateOpts.getOpt(CreateOpts.BlockSize.class, options); long blockSize = blockSizeOpt != null ? blockSizeOpt.getValue() : DEFAULT_BLOCK_SIZE; FSDataOutputStream out; out = fc.create(path, EnumSet.of(CreateFlag.APPEND)); byte[] data = getFileData(numBlocks, blockSize); out.write(data, 0, data.length); out.close(); } public static boolean exists(FileContext fc, Path p) throws IOException { return fc.util().exists(p); } public static boolean isFile(FileContext fc, Path p) throws IOException { try { return fc.getFileStatus(p).isFile(); } catch (FileNotFoundException e) { return false; } } public static boolean isDir(FileContext fc, Path p) throws IOException { try { return fc.getFileStatus(p).isDirectory(); } catch (FileNotFoundException e) { return false; } } public static boolean isSymlink(FileContext fc, Path p) throws IOException { try { return fc.getFileLinkStatus(p).isSymlink(); } catch (FileNotFoundException e) { return false; } } public static void writeFile(FileContext fc, Path path, byte b[]) throws IOException { FSDataOutputStream out = fc.create(path, EnumSet.of(CreateFlag.CREATE), CreateOpts.createParent()); out.write(b); out.close(); } public static byte[] readFile(FileContext fc, Path path, int len) throws IOException { DataInputStream dis = fc.open(path); byte[] buffer = new byte[len]; IOUtils.readFully(dis, buffer, 0, len); dis.close(); return buffer; } public FileStatus containsPath(FileContext fc, Path path, FileStatus[] dirList) { return containsPath(getTestRootPath(fc, path.toString()), dirList); } public static FileStatus containsPath(Path path, FileStatus[] dirList) { for (int i = 0; i < dirList.length; i++) { if (path.equals(dirList[i].getPath())) return dirList[i]; } return null; } public FileStatus containsPath(FileContext fc, String path, FileStatus[] dirList) { return containsPath(fc, new Path(path), dirList); } public static enum fileType { isDir, isFile, isSymlink }; public static void checkFileStatus(FileContext aFc, String path, fileType expectedType) throws IOException { FileStatus s = aFc.getFileStatus(new Path(path)); Assert.assertNotNull(s); if (expectedType == fileType.isDir) { Assert.assertTrue(s.isDirectory()); } else if (expectedType == fileType.isFile) { Assert.assertTrue(s.isFile()); } else if (expectedType == fileType.isSymlink) { Assert.assertTrue(s.isSymlink()); } Assert.assertEquals(aFc.makeQualified(new Path(path)), s.getPath()); } public static void checkFileLinkStatus(FileContext aFc, String path, fileType expectedType) throws IOException { FileStatus s = aFc.getFileLinkStatus(new Path(path)); Assert.assertNotNull(s); if (expectedType == fileType.isDir) { Assert.assertTrue(s.isDirectory()); } else if (expectedType == fileType.isFile) { Assert.assertTrue(s.isFile()); } else if (expectedType == fileType.isSymlink) { Assert.assertTrue(s.isSymlink()); } Assert.assertEquals(aFc.makeQualified(new Path(path)), s.getPath()); } }