content: /**
   * 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)));
      }
    }
  }
  