Oracle Oracle Certifications 1Z0-819 Questions & Answers

• Question 241:

  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 242:

  Your organization makes mlib.jar available to your cloud customers. While working on a new feature for mlib.jar, you see that the customer visible method public void enableService(String hostName, String portNumber) executes this code fragment

  

  and you see this grant is in the security policy file:

  

  What security vulnerability does this expose to your cloud customer's code?

  A. privilege escalation attack against the OS running the customer code

  B. SQL injection attack against the specified host and port

  C. XML injection attack against any mlib server

  D. none because the customer code base must also be granted SocketPermission

  E. denial of service attack against any reachable machine

  Correct Answer: E

  The correct answer is E. denial of service attack against any reachable machine. The code fragment shows that the enableService method uses the AccessController.doPrivileged method to create a new Socket with the specified hostname and portNumber. The security policy file grants the codebase permission to connect to any host using SocketPermission. This means that an attacker could potentially use this method to repeatedly create connections to any reachable machine, overwhelming its resources and causing a denial of service attack.

• Question 243:

  Given:

  

  What is the result?

  A. abyssinian oxicat korat laperm bengal sphynx

  B. abyssinian bengal korat laperm oxicat sphynx

  C. sphynx oxicat laperm korat bengal abyssinian

  D. nothing

  Correct Answer: C

• Question 244:

  Given:

  

  Which three classes successfully override printOne()? (Choose three.)

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  E. Option E

  F. Option F

  Correct Answer: ACD

• Question 245:

  Given the code fragment:

  

  What is the output?

  A. The compilation fails.

  B. [-1, -2, -3]

  C. [-3, -2, -1]

  D. A runtime exception is thrown.

  Correct Answer: D

• Question 246:

  Given:

  

  What is the output of this class?

  A. The compilation fails.

  B. [0). D, | 1). i, | 2). a]

  C. [). o, | 1). a, | 2).]

  D. [0). o, | 1). i, | 2). r]

  E. ArrayIndexOutOfBounds Exception is thrown at runtime.

  Correct Answer: A

• Question 247:

  There is a copyServiceAPI that has the org.copyservice. spi. Copy interface

  To use this service in a module, which module- info.java would be correct?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: C

• Question 248:

  Given the code fragment:

  

  Which "for" loop produces the same output?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: C

• Question 249:

  Given the code fragment:

  

  Which statement at line 1 will print Ping Pong?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: C

• Question 250:

  Given:

  

  What is the result?

  A. hat at store 1

  B. An IndexOutOfBoundsException is thrown at runtime.

  C. at once 0

  D. hat at store 4

  E. at once 1

  Correct Answer: A