Oracle Oracle Certifications 1Z0-816 Questions & Answers

• Question 41:

  Given:

  List list1 = new ArrayList<>();

  list1.add("A");

  list1.add("B");

  List list2 = List.copyOf(list1);

  list2.add("C");

  List> list3 = List.of(list1, list2);

  System.out.println(list3);

  What is the result?

  A. [[A, B],[A, B]]

  B. An exception is thrown at run time.

  C. [[A, B], [A, B, C]]

  D. [[A, B, C], [A, B, C]]

  Correct Answer: B

  

• Question 42:

  Given:

  

  Which three actions implement Java SE security guidelines? (Choose three.)

  A. Change line 7 to return names.clone();.

  B. Change line 4 to this.names = names.clone();.

  C. Change the getNames() method name to get$Names().

  D. Change line 6 to public synchronized String[] getNames() {.

  E. Change line 2 to private final String[] names;.

  F. Change line 3 to private Secret(String[] names) {.

  G. Change line 2 to protected volatile String[] names;.

  Correct Answer: EFG

• Question 43:

  Given:

  

  You want the code to produce this output:

  John Joe Jane

  Which code fragment should be inserted on line 1 and line 2 to produce the output?

  A. Insert Comparator on line 1. Insert public int compare(Person p1, Person p2) { return p1.name.compare(p2.name); } on line 2.

  B. Insert Comparator on line 1. Insert public int compareTo(Person person) { return person.name.compareTo(this.name); } on line 2.

  C. Insert Comparable on line 1. Insert public int compare(Person p1, Person p2) { return p1.name.compare(p2.name); } on line 2.

  D. Insert Comparator on line 1. Insert public int compare(Person person) { return person.name.compare(this.name); } on line 2.

  Correct Answer: B

  Reference: https://www.coursehero.com/file/p320ss6/Override-public-int-compareTo-Person-otherCompare-this-objects-name-to-others/

• Question 44:

  Given:

  

  and

  

  What is the result?

  A. A NullPointerException is thrown at run time.

  B. The compilation fails.

  C. 1 Null null

  D. 1

  E. A ClassCastException is thrown at run time.

  Correct Answer: B

  

• Question 45:

  Which statement about a functional interface is true?

  A. It must be defined with the public access modifier.

  B. It must be annotated with @FunctionalInterface.

  C. It is declared with a single abstract method.

  D. It is declared with a single default method.

  E. It cannot have any private methods and static methods.

  Correct Answer: C

  Reference: https://www.geeksforgeeks.org/functional-interfaces-java/

• Question 46:

  

  Which interface in the java.util.function package will return a void return type?

  A. Supplier

  B. Predicate

  C. Function

  D. Consumer

  Correct Answer: D

  Reference: https://www.geeksforgeeks.org/java-8-consumer-interface-in-java-with-examples/

• Question 47:

  Given:

  

  You want to use the myResource class in a try-with-resources statement. Which change will accomplish this?

  A. Extend AutoCloseable and override the close method.

  B. Implement AutoCloseable and override the autoClose method.

  C. Extend AutoCloseable and override the autoClose method.

  D. Implement AutoCloseable and override the close method.

  Correct Answer: D

  Reference: https://stackabuse.com/the-try-with-resources-statement-in-java/

• Question 48:

  Given:

  

  Which two are correct? (Choose two.)

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  E. Option E

  Correct Answer: CD

• Question 49:

  Given: Assume the file on path does not exist. What is the result?

  

  A. The compilation fails.

  B. /u01/work/filestore.txt is not deleted.

  C. Exception

  D. /u01/work/filestore.txt is deleted.

  Correct Answer: A

  

• Question 50:

  Given an application with a main module that has this module-info.java file:

  

  Which two are true? (Choose two.)

  A. A module providing an implementation of country.CountryDetails can be compiled and added without recompiling the main module.

  B. A module providing an implementation of country.CountryDetails must have a requires main; directive in its module-info.java file.

  C. An implementation of country.countryDetails can be added to the main module.

  D. To compile without an error, the application must have at least one module in the module source path that provides an implementation of country.CountryDetails.

  E. To run without an error, the application must have at least one module in the module path that provides an implementation of country.CountryDetails.

  Correct Answer: BD

  Reference: https://stackoverflow.com/questions/49476559/java-9-error-not-in-a-module-on-the-modulesource-path