org.apache.apex.examples.kafka.kafka2hdfs.ApplicationTest.java Source code

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/**
 * 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.apex.examples.kafka.kafka2hdfs;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;

import javax.validation.ConstraintViolationException;

import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.apex.malhar.kafka.AbstractKafkaInputOperator;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.net.NetUtils;

import com.datatorrent.api.LocalMode;

import info.batey.kafka.unit.KafkaUnit;
import info.batey.kafka.unit.KafkaUnitRule;
import kafka.producer.KeyedMessage;

import static org.junit.Assert.assertTrue;

/**
 * Test the DAG declaration in local mode.
 */
public class ApplicationTest {
    private static final Logger LOG = LoggerFactory.getLogger(ApplicationTest.class);
    private static final String TOPIC = "kafka2hdfs";

    private static final int zkPort = NetUtils.getFreeSocketPort();
    private static final int brokerPort = NetUtils.getFreeSocketPort();
    private static final String BROKER = "localhost:" + brokerPort;
    private static final String FILE_NAME = "test";
    private static final String FILE_DIR = "./target/tmp/FromKafka";
    private static final String FILE_PATH = FILE_DIR + "/" + FILE_NAME + ".0"; // first part

    // test messages
    private static String[] lines = { "1st line", "2nd line", "3rd line", "4th line", "5th line", };

    // broker port must match properties.xml
    @Rule
    public KafkaUnitRule kafkaUnitRule = new KafkaUnitRule(zkPort, brokerPort);

    @Test
    public void testApplication() throws Exception {
        try {
            // delete output file if it exists
            File file = new File(FILE_PATH);
            file.delete();

            // write messages to Kafka topic
            writeToTopic();

            // run app asynchronously; terminate after results are checked
            LocalMode.Controller lc = asyncRun();

            // check for presence of output file
            chkOutput();

            // compare output lines to input
            compare();

            lc.shutdown();
        } catch (ConstraintViolationException e) {
            Assert.fail("constraint violations: " + e.getConstraintViolations());
        }
    }

    private void writeToTopic() {
        KafkaUnit ku = kafkaUnitRule.getKafkaUnit();
        ku.createTopic(TOPIC);
        for (String line : lines) {
            KeyedMessage<String, String> kMsg = new KeyedMessage<>(TOPIC, line);
            ku.sendMessages(kMsg);
        }
        LOG.debug("Sent messages to topic {}", TOPIC);
    }

    private Configuration getConfig() {
        Configuration conf = new Configuration(false);
        String pre = "dt.operator.kafkaIn.prop.";
        conf.setEnum(pre + "initialOffset", AbstractKafkaInputOperator.InitialOffset.EARLIEST);
        conf.setInt(pre + "initialPartitionCount", 1);
        conf.set(pre + "topics", TOPIC);
        conf.set(pre + "clusters", BROKER);

        pre = "dt.operator.fileOut.prop.";
        conf.set(pre + "filePath", FILE_DIR);
        conf.set(pre + "baseName", FILE_NAME);
        conf.setInt(pre + "maxLength", 40);
        conf.setInt(pre + "rotationWindows", 3);

        return conf;
    }

    private LocalMode.Controller asyncRun() throws Exception {
        Configuration conf = getConfig();
        LocalMode lma = LocalMode.newInstance();
        lma.prepareDAG(new KafkaApp(), conf);
        LocalMode.Controller lc = lma.getController();
        lc.runAsync();
        return lc;
    }

    private static void chkOutput() throws Exception {
        File file = new File(FILE_PATH);
        final int MAX = 60;
        for (int i = 0; i < MAX && (!file.exists()); ++i) {
            LOG.debug("Sleeping, i = {}", i);
            Thread.sleep(1000);
        }
        if (!file.exists()) {
            String msg = String.format("Error: %s not found after %d seconds%n", FILE_PATH, MAX);
            throw new RuntimeException(msg);
        }
    }

    private static void compare() throws Exception {
        // read output file
        File file = new File(FILE_PATH);
        BufferedReader br = new BufferedReader(new FileReader(file));
        ArrayList<String> list = new ArrayList<>();
        String line;
        while (null != (line = br.readLine())) {
            list.add(line);
        }
        br.close();

        // compare
        Assert.assertEquals("number of lines", list.size(), lines.length);
        for (int i = 0; i < lines.length; ++i) {
            assertTrue("line", lines[i].equals(list.get(i)));
        }
    }
}