org.apache.hadoop.example.ITUseMiniCluster.java Source code

Introduction

Here is the source code for org.apache.hadoop.example.ITUseMiniCluster.java

Source

/*
 * 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.example;

import java.io.IOException;
import java.net.URISyntaxException;

import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.Path;

import org.apache.hadoop.conf.Configuration;

import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;

import org.apache.hadoop.hdfs.web.WebHdfsTestUtil;
import org.apache.hadoop.hdfs.web.WebHdfsConstants;

/**
 * Ensure that we can perform operations against the shaded minicluster
 * given the API and runtime jars by performing some simple smoke tests.
 */
public class ITUseMiniCluster {

    private static final Logger LOG = LoggerFactory.getLogger(ITUseMiniCluster.class);

    private MiniDFSCluster cluster;

    private static final String TEST_PATH = "/foo/bar/cats/dee";
    private static final String FILENAME = "test.file";

    private static final String TEXT = "Lorem ipsum dolor sit amet, consectetur "
            + "adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore "
            + "magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation "
            + "ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute "
            + "irure dolor in reprehenderit in voluptate velit esse cillum dolore eu "
            + "fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident,"
            + " sunt in culpa qui officia deserunt mollit anim id est laborum.";

    @Before
    public void clusterUp() throws IOException {
        final Configuration conf = new HdfsConfiguration();
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3).build();
        cluster.waitActive();
    }

    @After
    public void clusterDown() {
        if (cluster != null) {
            cluster.close();
        }
    }

    @Test
    public void useHdfsFileSystem() throws IOException {
        try (FileSystem fs = cluster.getFileSystem()) {
            simpleReadAfterWrite(fs);
        }
    }

    public void simpleReadAfterWrite(final FileSystem fs) throws IOException {
        LOG.info("Testing read-after-write with FS implementation: {}", fs);
        final Path path = new Path(TEST_PATH, FILENAME);
        if (!fs.mkdirs(path.getParent())) {
            throw new IOException("Mkdirs failed to create " + TEST_PATH);
        }
        try (FSDataOutputStream out = fs.create(path)) {
            out.writeUTF(TEXT);
        }
        try (FSDataInputStream in = fs.open(path)) {
            final String result = in.readUTF();
            Assert.assertEquals("Didn't read back text we wrote.", TEXT, result);
        }
    }

    @Test
    public void useWebHDFS() throws IOException, URISyntaxException {
        try (FileSystem fs = WebHdfsTestUtil.getWebHdfsFileSystem(cluster.getConfiguration(0),
                WebHdfsConstants.WEBHDFS_SCHEME)) {
            simpleReadAfterWrite(fs);
        }
    }
}