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.flink.runtime.fs.hdfs; import org.apache.flink.core.fs.AbstractRecoverableWriterTest; import org.apache.flink.core.fs.FileSystem; import org.apache.flink.core.fs.Path; import org.apache.flink.runtime.util.HadoopUtils; import org.apache.flink.util.OperatingSystem; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hdfs.MiniDFSCluster; import org.junit.AfterClass; import org.junit.Assume; import org.junit.BeforeClass; import org.junit.ClassRule; import org.junit.rules.TemporaryFolder; import java.io.File; /** * Tests for the {@link HadoopRecoverableWriter}. */ public class HadoopRecoverableWriterTest extends AbstractRecoverableWriterTest { @ClassRule public static final TemporaryFolder TEMP_FOLDER = new TemporaryFolder(); private static MiniDFSCluster hdfsCluster; /** The cached file system instance. */ private static FileSystem fileSystem; private static Path basePath; @BeforeClass public static void testHadoopVersion() { Assume.assumeTrue(HadoopUtils.isMinHadoopVersion(2, 7)); } @BeforeClass public static void verifyOS() { Assume.assumeTrue("HDFS cluster cannot be started on Windows without extensions.", !OperatingSystem.isWindows()); } @BeforeClass public static void createHDFS() throws Exception { final File baseDir = TEMP_FOLDER.newFolder(); final Configuration hdConf = new Configuration(); hdConf.set(MiniDFSCluster.HDFS_MINIDFS_BASEDIR, baseDir.getAbsolutePath()); final MiniDFSCluster.Builder builder = new MiniDFSCluster.Builder(hdConf); hdfsCluster = builder.build(); final org.apache.hadoop.fs.FileSystem hdfs = hdfsCluster.getFileSystem(); fileSystem = new HadoopFileSystem(hdfs); basePath = new Path(hdfs.getUri() + "/tests"); } @AfterClass public static void destroyHDFS() throws Exception { if (hdfsCluster != null) { hdfsCluster.getFileSystem().delete(new org.apache.hadoop.fs.Path(basePath.toUri()), true); hdfsCluster.shutdown(); } } @Override public Path getBasePath() { return basePath; } @Override public FileSystem initializeFileSystem() { return fileSystem; } }