Free Oracle 1Z0-809 Exam Questions

Become Oracle Certified with updated 1Z0-809 exam questions and correct answers

Page: 1 / 94

Total 469 Questions | Updated On: Jan 28, 2026

Add To Cart

Question 1

Given the code fragments:

class MyThread implements Runnable {

private static AtomicInteger count = new AtomicInteger (0);

public void run () {

int x = count.incrementAndGet();

System.out.print (x+” “);

}

and

Thread thread1 = new Thread(new MyThread());

Thread thread2 = new Thread(new MyThread());

Thread thread3 = new Thread(new MyThread());

Thread [] ta = {thread1, thread2, thread3};

for (int x= 0; x < 3; x++) {

ta[x].start();

}

Which statement is true?

A : The program prints 1 2 3 and the order is unpredictable

B : The program prints 1 2 3.

C : The program prints 1 1 1

D : A compilation error occurs.

Answer: A

Question 2

What will be the result of compiling and executing class Test?

1. package com.udayan.ocp;

3. class X {

4. class Y {

5. private void m() {

6. System.out.println("INNER");

7. }

8. }

10. public void invokeInner() {

11. Y obj = new Y(); //Line 9

12. obj.m(); //Line 10

13. }

14. }

15.

16. public class Test {

17. public static void main(String[] args) {

18. new X().invokeInner();

19. }

20. }

A : Compilation error at Line 9 as instance of outer class (X) is needed to create the instance of inner class (Y)

B : Compilation error at Line 10 as private method m() cannot be invoked outside the body of inner class (Y)

C : INNER

D : Exception is thrown at runtime

Answer: C

Question 3

Consider the code of Greet.java file:

1. package com.udayan.ocp;

3. public final class Greet {

4. private String msg;

5. public Greet(String msg) {

6. this.msg = msg;

7. }

9. public String getMsg() {

10. return msg;

11. }

12.

13. public void setMsg(String msg) {

14. this.msg = msg;

15. }

16. }

Is Greet class an immutable class?

A : Yes

B : No

Answer: B

Question 4

Given code of Test.java file:

1. package com.udayan.ocp;

3. import java.util.stream.Stream;

5. public class Test {

6. public static void main(String[] args) {

7. Stream stream = Stream.of("d", "cc", "bbb", "aaaa");

8. stream.sorted().forEach(System.out::println);

9. }

10. }

Which of the following needs to be done, so that output is:

bbb

aaaa

A : No need to make any changes, on execution given code prints expected result

B : Replace stream.sorted() with stream.sorted((s1,s2) -> s1.length() - s2.length())

C : Replace stream.sorted() with stream.sorted((s1,s2) -> s2.length() - s1.length())

Answer: B

Question 5

Given the content of Operator.java, EngineOperator.java, and Engine.java files:

and the code fragment:

What is the result?

A : The Engine.java file fails to compile

B : The EngineOperator.java file fails to compile

C : The Operator.java file fails to compile

D : ON OFF

Answer: A

Page: 1 / 94

Total 469 Questions | Updated On: Jan 28, 2026

Add To Cart