oracle 1z0-809 practice test

Given the code fragment:
Stream<List<String>> iStr= Stream.of (
Arrays.asList (1, John),
Arrays.asList (2, null)0;
Stream<<String> nInSt = iStr.flatMapToInt ((x) -> x.stream ());
nInSt.forEach (System.out :: print);
What is the result?

• A. 1John2null
• B. 12
• C. A NullPointerException is thrown at run time.
• D. A compilation error occurs.

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?

• A. List<String> fc = Files.list(file);fc.stream().forEach (s - > System.out.println(s));
• B. Stream<String> fc = Files.readAllLines (file);fc.forEach (s - > System.out.println(s));
• C. List<String> fc = readAllLines(file);fc.stream().forEach (s - > System.out.println(s));
• D. Stream<String> fc = Files.lines (file);fc.forEach (s - > System.out.println(s));

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?

• A. The method deletes all the .class files in the Projects directory and its subdirectories.
• B. The method deletes the .class files of the Projects directory only.
• C. The method executes and does not make any changes to the Projects directory.
• D. The method throws an IOException.

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?

• A. Comment the lines 28, 29 and 30.
• B. Replace line 26 with:} catch (Exception | ArithmeticException | NumberFormatException e) {
• C. Replace line 26 with:} catch (ArithmeticException | NumberFormatException e) {
• D. Replace line 27 with:throw e;

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);
What is the output?

• A. {EUROPE = [Italy, Germany], ASIA = [Japan]}
• B. {ASIA = [Japan], EUROPE = [Italy, Germany]}
• C. {EUROPE = [Germany, Italy], ASIA = [Japan]}
• D. {EUROPE = [Germany], EUROPE = [Italy], ASIA = [Japan]}

Given the code fragment:
Map<Integer, String> books = new TreeMap<>();
books.put (1007, A);
books.put (1002, C);
books.put (1001, B);
books.put (1003, B);
System.out.println (books);
What is the result?

• A. {1007 = A, 1002 = C, 1001 = B, 1003 = B}
• B. {1001 = B, 1002 = C, 1003 = B, 1007 = A}
• C. {1002 = C, 1003 = B, 1007 = A}
• D. {1007 = A, 1001 = B, 1003 = B, 1002 = C}

Given:
class Book {
int id;
String name;
public Book (int id, String name) {
this.id = id;
this.name = name;
}
public boolean equals (Object obj) { //line n1
boolean output = false;
Book b = (Book) obj;
if (this.name.equals(b name))}
output = true;
}
return output;
}
}
and the code fragment:
Book b1 = new Book (101, Java Programing);
Book b2 = new Book (102, Java Programing);
System.out.println (b1.equals(b2)); //line n2
Which statement is true?

• A. The program prints true.
• B. The program prints false.
• C. A compilation error occurs. To ensure successful compilation, replace line n1 with:boolean equals (Book obj) {
• D. A compilation error occurs. To ensure successful compilation, replace line n2 with:System.out.println (b1.equals((Object) b2));

Given the content of /resourses/Message.properties:
welcome1=Good day!
and given the code fragment:
Properties prop = new Properties ();
FileInputStream fis = new FileInputStream (/resources/Message.properties);
prop.load(fis);
System.out.println(prop.getProperty(welcome1));
System.out.println(prop.getProperty(welcome2, Test));//line n1
System.out.println(prop.getProperty(welcome3));
What is the result?

• A. Good day!Testfollowed by an Exception stack trace
• B. Good day!followed by an Exception stack trace
• C. Good day!Testnull
• D. A compilation error occurs at line n1.

Which action can be used to load a database driver by using JDBC3.0?

• A. Add the driver class to the META-INF/services folder of the JAR file.
• B. Include the JDBC driver class in a jdbc.properties file.
• C. Use the java.lang.Class.forName method to load the driver class.
• D. Use the DriverManager.getDriver method to load the driver class.

Given the code fragment:
Path p1 = Paths.get(/Pics/MyPic.jpeg);
System.out.println (p1.getNameCount() +
: + p1.getName(1) +
: + p1.getFileName());
Assume that the Pics directory does NOT exist.
What is the result?

• A. An exception is thrown at run time.
• B. 2:MyPic.jpeg: MyPic.jpeg
• C. 1:Pics:/Pics/ MyPic.jpeg
• D. 2:Pics: MyPic.jpeg