Oracle 1z0-809 Exam Practice Questions (P. 3)

Given the code fragment:
Stream<List<String>> iStr= Stream.of (
Arrays.asList ("1", "John"),
Arrays.asList ("2", null));
Stream<<String> nInSt = iStr.flatMapToInt ((x) -> x.stream ()); nInSt.forEach (System.out :: print);
What is the result?

Given the code fragment:
Path file = Paths.get ("courses.txt");
// line n1
Assume the courses.txt is accessible.
Which code fragment can be inserted at line n1 to enable the code to print the content of the courses.txt file?

Given the code fragment:
public void recDelete (String dirName) throws IOException {
File [ ] listOfFiles = new File (dirName) .listFiles();
if (listOfFiles ! = null && listOfFiles.length >0) {
for (File aFile : listOfFiles) {
if (aFile.isDirectory ()) {
recDelete (aFile.getAbsolutePath ());
} else {
if (aFile.getName ().endsWith (".class"))
aFile.delete ();
}
}
}
}
Assume that Projects contains subdirectories that contain .class files and is passed as an argument to the recDelete () method when it is invoked.
What is the result?

Given the code fragments:
4. void doStuff() throws ArithmeticException, NumberFormatException, Exception {
5. if (Math.random() >-1 throw new Exception ("Try again");
6. }
and
24. try {
25. doStuff ( ):
26. } catch (ArithmeticException | NumberFormatException | Exception e) {
27. System.out.println (e.getMessage()); }
28. catch (Exception e) {
29. System.out.println (e.getMessage()); }
30. }
Which modification enables the code to print Try again?

Given the definition of the Country class:
public class country {
public enum Continent {ASIA, EUROPE}
String name;
Continent region;
public Country (String na, Continent reg) {
name = na, region = reg;
}
public String getName () {return name;}
public Continent getRegion () {return region;}
}
and the code fragment:
List<Country> couList = Arrays.asList (
new Country ("Japan", Country.Continent.ASIA),
new Country ("Italy", Country.Continent.EUROPE),
new Country ("Germany", Country.Continent.EUROPE));
Map<Country.Continent, List<String>> regionNames = couList.stream ()
.collect(Collectors.groupingBy (Country ::getRegion,
Collectors.mapping(Country::getName, Collectors.toList()))));
System.out.println(regionNames);