Application implements StreamingApplication { public void setExtraOutputFileName(String fileName) { this.extraOutputFileName = fileName; }  void setExtraOutputFileName(String fileName); @Override void populateDAG(DAG dag, Configuration conf);  }
@Test public void testIterationApp() throws Exception { LocalMode lma = LocalMode.newInstance(); Configuration conf = new Configuration(false); Application app = new Application(); String outputFileName = "target/output.txt"; long timeout = 10 * 1000; new File(outputFileName).delete(); app.setExtraOutputFileName(outputFileName); lma.prepareDAG(app, conf); LocalMode.Controller lc = lma.getController(); lc.runAsync(); long startTime = System.currentTimeMillis(); do { try { Thread.sleep(500); } catch (InterruptedException ex) { break; } File file = new File(outputFileName); if (file.length() > 50) { break; } } while (System.currentTimeMillis() - startTime < timeout); lc.shutdown(); try (BufferedReader br = new BufferedReader(new FileReader(outputFileName))) { Assert.assertEquals("1", br.readLine()); Assert.assertEquals("1", br.readLine()); Assert.assertEquals("2", br.readLine()); Assert.assertEquals("3", br.readLine()); Assert.assertEquals("5", br.readLine()); Assert.assertEquals("8", br.readLine()); Assert.assertEquals("13", br.readLine()); Assert.assertEquals("21", br.readLine()); Assert.assertEquals("34", br.readLine()); Assert.assertEquals("55", br.readLine()); Assert.assertEquals("89", br.readLine()); Assert.assertEquals("144", br.readLine()); Assert.assertEquals("233", br.readLine()); Assert.assertEquals("377", br.readLine()); Assert.assertEquals("610", br.readLine()); Assert.assertEquals("987", br.readLine()); } }