code: /**
   * Copyright (c) 2015 Yahoo! Inc. All rights reserved.
   * <p>
   * Licensed 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
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * 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. See accompanying
   * LICENSE file.
   */
  package com.yahoo.ycsb.measurements.exporter;
  
  import com.yahoo.ycsb.generator.ZipfianGenerator;
  import com.yahoo.ycsb.measurements.Measurements;
  import org.codehaus.jackson.JsonNode;
  import org.codehaus.jackson.map.ObjectMapper;
  import org.testng.annotations.Test;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.util.Properties;
  
  import static org.testng.AssertJUnit.assertEquals;
  import static org.testng.AssertJUnit.assertTrue;
  
  public class TestMeasurementsExporter {
      @Test
      public void testJSONArrayMeasurementsExporter() throws IOException {
          Properties props = new Properties();
          props.put(Measurements.MEASUREMENT_TYPE_PROPERTY, "histogram");
          Measurements mm = new Measurements(props);
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          JSONArrayMeasurementsExporter export = new JSONArrayMeasurementsExporter(out);
  
          long min = 5000;
          long max = 100000;
          ZipfianGenerator zipfian = new ZipfianGenerator(min, max);
          for (int i = 0; i < 1000; i++) {
              int rnd = zipfian.nextValue().intValue();
              mm.measure("UPDATE", rnd);
          }
          mm.exportMeasurements(export);
          export.close();
  
          ObjectMapper mapper = new ObjectMapper();
          JsonNode  json = mapper.readTree(out.toString("UTF-8"));
          assertTrue(json.isArray());
          assertEquals(json.get(0).get("measurement").asText(), "Operations");
          assertEquals(json.get(4).get("measurement").asText(), "MaxLatency(us)");
          assertEquals(json.get(11).get("measurement").asText(), "4");
      }
  }
  