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.hdfs; import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertTrue; import static org.junit.Assert.fail; import java.io.FileNotFoundException; import java.io.IOException; import java.util.Random; import org.apache.commons.logging.impl.Log4JLogger; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FSDataOutputStream; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.permission.FsPermission; import org.apache.hadoop.hdfs.DFSClient.DFSDataInputStream; import org.apache.hadoop.hdfs.protocol.HdfsFileStatus; import org.apache.hadoop.hdfs.server.namenode.FSNamesystem; import org.apache.hadoop.hdfs.server.namenode.NameNode; import org.apache.hadoop.security.UserGroupInformation; import org.apache.log4j.Level; import org.junit.Test; /** * This class tests the FileStatus API. */ public class TestFileStatus { { ((Log4JLogger) FSNamesystem.LOG).getLogger().setLevel(Level.ALL); ((Log4JLogger) FileSystem.LOG).getLogger().setLevel(Level.ALL); } static final long seed = 0xDEADBEEFL; static final int blockSize = 8192; static final int fileSize = 16384; private void writeFile(FileSystem fileSys, Path name, int repl, int fileSize, int blockSize) throws IOException { // create and write a file that contains three blocks of data FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf().getInt("io.file.buffer.size", 4096), (short) repl, (long) blockSize); byte[] buffer = new byte[fileSize]; Random rand = new Random(seed); rand.nextBytes(buffer); stm.write(buffer); stm.close(); } private void checkFile(FileSystem fileSys, Path name, int repl) throws IOException { DFSTestUtil.waitReplication(fileSys, name, (short) repl); } /** * Tests various options of DFSShell. */ @Test public void testFileStatus() throws Exception { Configuration conf = new Configuration(); conf.setInt(DFSConfigKeys.DFS_LIST_LIMIT, 2); MiniDFSCluster cluster = new MiniDFSCluster(conf, 1, true, null); FileSystem fs = cluster.getFileSystem(); final HftpFileSystem hftpfs = cluster.getHftpFileSystem(); final DFSClient dfsClient = new DFSClient(NameNode.getAddress(conf), conf); try { // // check that / exists // Path path = new Path("/"); System.out.println("Path : \"" + path.toString() + "\""); assertTrue("/ should be a directory", fs.getFileStatus(path).isDir() == true); // make sure getFileInfo returns null for files which do not exist HdfsFileStatus fileInfo = dfsClient.getFileInfo("/noSuchFile"); assertTrue(fileInfo == null); // create a file in home directory // Path file1 = new Path("filestatus.dat"); writeFile(fs, file1, 1, fileSize, blockSize); System.out.println("Created file filestatus.dat with one " + " replicas."); checkFile(fs, file1, 1); System.out.println("Path : \"" + file1 + "\""); // test getFileStatus on a file FileStatus status = fs.getFileStatus(file1); assertTrue(file1 + " should be a file", status.isDir() == false); assertTrue(status.getBlockSize() == blockSize); assertTrue(status.getReplication() == 1); assertTrue(status.getLen() == fileSize); assertEquals(fs.makeQualified(file1).toString(), status.getPath().toString()); // test getVisbileLen DFSDataInputStream fin = (DFSDataInputStream) fs.open(file1); assertEquals(status.getLen(), fin.getVisibleLength()); // test listStatus on a file FileStatus[] stats = fs.listStatus(file1); assertEquals(1, stats.length); status = stats[0]; assertTrue(file1 + " should be a file", status.isDir() == false); assertTrue(status.getBlockSize() == blockSize); assertTrue(status.getReplication() == 1); assertTrue(status.getLen() == fileSize); assertEquals(fs.makeQualified(file1).toString(), status.getPath().toString()); // test file status on a directory Path dir = new Path("/test/mkdirs"); // test listStatus on a non-existent file/directory stats = fs.listStatus(dir); assertTrue(null == stats); try { status = fs.getFileStatus(dir); fail("getFileStatus of non-existent path should fail"); } catch (FileNotFoundException fe) { assertTrue(fe.getMessage().startsWith("File does not exist")); } // create the directory assertTrue(fs.mkdirs(dir)); assertTrue(fs.exists(dir)); System.out.println("Dir : \"" + dir + "\""); // test getFileStatus on an empty directory status = fs.getFileStatus(dir); assertTrue(dir + " should be a directory", status.isDir()); assertTrue(dir + " should be zero size ", status.getLen() == 0); assertEquals(fs.makeQualified(dir).toString(), status.getPath().toString()); // test listStatus on an empty directory stats = fs.listStatus(dir); assertEquals(dir + " should be empty", 0, stats.length); assertEquals(dir + " should be zero size ", 0, fs.getContentSummary(dir).getLength()); assertEquals(dir + " should be zero size using hftp", 0, hftpfs.getContentSummary(dir).getLength()); assertTrue(dir + " should be zero size ", fs.getFileStatus(dir).getLen() == 0); System.out.println("Dir : \"" + dir + "\""); // create another file that is smaller than a block. // Path file2 = new Path(dir, "filestatus2.dat"); writeFile(fs, file2, 1, blockSize / 4, blockSize); System.out.println("Created file filestatus2.dat with one " + " replicas."); checkFile(fs, file2, 1); System.out.println("Path : \"" + file2 + "\""); // verify file attributes status = fs.getFileStatus(file2); assertTrue(status.getBlockSize() == blockSize); assertTrue(status.getReplication() == 1); file2 = fs.makeQualified(file2); assertEquals(file2.toString(), status.getPath().toString()); // create another file in the same directory Path file3 = new Path(dir, "filestatus3.dat"); writeFile(fs, file3, 1, blockSize / 4, blockSize); System.out.println("Created file filestatus3.dat with one " + " replicas."); checkFile(fs, file3, 1); file3 = fs.makeQualified(file3); // verify that the size of the directory increased by the size // of the two files final int expected = blockSize / 2; assertEquals(dir + " size should be " + expected, expected, fs.getContentSummary(dir).getLength()); assertEquals(dir + " size should be " + expected + " using hftp", expected, hftpfs.getContentSummary(dir).getLength()); // test listStatus on a non-empty directory stats = fs.listStatus(dir); assertEquals(dir + " should have two entries", 2, stats.length); assertEquals(file2.toString(), stats[0].getPath().toString()); assertEquals(file3.toString(), stats[1].getPath().toString()); // test iterative listing // now dir has 2 entries, create one more Path dir3 = fs.makeQualified(new Path(dir, "dir3")); fs.mkdirs(dir3); dir3 = fs.makeQualified(dir3); stats = fs.listStatus(dir); assertEquals(dir + " should have three entries", 3, stats.length); assertEquals(dir3.toString(), stats[0].getPath().toString()); assertEquals(file2.toString(), stats[1].getPath().toString()); assertEquals(file3.toString(), stats[2].getPath().toString()); // now dir has 3 entries, create two more Path dir4 = fs.makeQualified(new Path(dir, "dir4")); fs.mkdirs(dir4); dir4 = fs.makeQualified(dir4); Path dir5 = fs.makeQualified(new Path(dir, "dir5")); fs.mkdirs(dir5); dir5 = fs.makeQualified(dir5); stats = fs.listStatus(dir); assertEquals(dir + " should have five entries", 5, stats.length); assertEquals(dir3.toString(), stats[0].getPath().toString()); assertEquals(dir4.toString(), stats[1].getPath().toString()); assertEquals(dir5.toString(), stats[2].getPath().toString()); assertEquals(file2.toString(), stats[3].getPath().toString()); assertEquals(file3.toString(), stats[4].getPath().toString()); { //test permission error on hftp fs.setPermission(dir, new FsPermission((short) 0)); try { final String username = UserGroupInformation.getCurrentUser().getShortUserName() + "1"; final HftpFileSystem hftp2 = cluster.getHftpFileSystemAs(username, conf, "somegroup"); hftp2.getContentSummary(dir); fail(); } catch (IOException ioe) { FileSystem.LOG.info("GOOD: getting an exception", ioe); } } } finally { fs.close(); cluster.shutdown(); } } }