Oracle Oracle Certifications 1Z0-819 Questions & Answers

• Question 141:

  Given:

  

  What is the result?

  A. Keys: 4 Values: 4 Map: 0

  B. Keys: 4 Values: 4 Map: 4

  C. The compilation fails.

  D. Keys: 0 Values: 0 Map:

  E. Keys: 0 Values: 0 Map: 0

  Correct Answer: B

• Question 142:

  Which module-info.java is correct for a service provider for a print service defined in the PrintServiceAPI module?

  A. module PrintServiceProvider {

  requires PrintServiceAPI;

  exports org.printservice.spi;

  B. module PrintServiceProvider { requires PrintServiceAPI; provides org.printservice.spi.Print with com.provider.PrintService; }

  C. module PrintServiceProvider { requires PrintServiceAPI; uses com.provider.PrintService; }

  D. module PrintServiceProvider { requires PrintServiceAPI; exports org.printservice.spi.Print with com.provider.PrintService; }

  Correct Answer: B

• Question 143:

  Which is a proper JDBC URL?

  A. jdbe.mysql.com://localhost:3306/database

  B. http://localhost.mysql.com:3306/database

  C. http://localhost mysql.jdbc:3306/database

  D. jdbc:mysql://localhost:3306/database

  Correct Answer: D

  Reference: https://vladmihalcea.com/jdbc-driver-connection-url-strings/

• Question 144:

  Given:

  

  You want to obtain the Filechannel object on line 1. Which code fragment will accomplish this?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: A

• Question 145:

  Given:

  var data = new ArrayList<>();

  data.add("Peter");

  data.add(30);

  data.add("Market Road");

  data.set(1, 25);

  data.remove(2);

  data.set(3, 1000L);

  System.out.print(data);

  What is the output?

  A. [Market Road, 1000]

  B. [Peter, 30, Market Road]

  C. [Peter, 25, null, 1000]

  D. An exception is thrown at run time.

  Correct Answer: D

  

• Question 146:

  Given: What is the result?

  

  A. An indexOutofBoundsException is thrown at runtime.

  B. At once 0

  C. Hat at store 4

  D. At once 1

  E. Hat at store 1

  Correct Answer: E

• Question 147:

  Given:

  

  Which two are secure serialization of these objects? (Choose two.)

  A. Define the serialPersistentFields array field.

  B. Declare fields transient.

  C. Implement only readResolve to replace the instance with a serial proxy and not writeReplace.

  D. Make the class abstract.

  E. Implement only writeReplace to replace the instance with a serial proxy and not readResolve.

  Correct Answer: AC

• Question 148:

  Given:

  

  Which two interfaces can be used in lambda expressions? (Choose two.)

  A. MyInterface1

  B. MyInterface3

  C. MyInterface5

  D. MyInterface2

  E. MyInterface4

  Correct Answer: AB

• Question 149:

  Examine these module declarations:

  

  Which two statements are correct? (Choose two.)

  A. The ServiceProvider module is the only module that, at run time, can provide the com.example.api API.

  B. The placement of the com.example.api API in a separate module, ServiceAPI, makes it easy to install multiple provider modules.

  C. The Consumer module should require the ServiceProvider module.

  D. The ServiceProvider module should export the com.myimpl package.

  E. The ServiceProvider module does not know the identity of a module (such as Consumer) that uses the com.example.api API.

  Correct Answer: AC

• Question 150:

  Given: When is the readObject method called?

  

  A. before this object is deserialized

  B. after this object is deserialized

  C. before this object Is serialized

  D. The method is never called.

  E. after this object is serialized

  Correct Answer: B

  Reference: https://www.oracle.com/technical-resources/articles/java/javaserial.html