Decoupling

Question 1

What are some elements used in networking to make it as decoupled as possible?

Answer 1

• MessageHandler interface
• Communicator interface

Question 2

How does MessageHandler aid in decoupling?

Answer 2

It allows the existance of multiple handling possibilities for the messages. This way networking is decoupled from the functionality of handling a message.

Question 3

How does Communicator aid in decoupling?

Answer 3

Allows the MessageHandler implementation to use a communicator instead of a client. This way the functionality of handling a message is decoupled from networking.

Question 4

What does synchronous mean in this context?

Answer 4

Sth is synchrounous when it executes only one thing at a time.

Question 5

What does blocking mean in this context?

Answer 5

Whenever you call a method,
your program will only continue after that method has fully completed its operations/computations.

Question 6

What is mocking used for?

Answer 6

To fake the functionality of dependencies that would be too complicated to create. Any class or interface can be mocked.

Question 7

How does mocking work?

Answer 7

Essentially mocking a class/interface mean creating a stub implementation. The created object and the associated methods can be used without actually providing an implementation.

Question 8

How to use mocking for a method that returns something?

Answer 8

You have to specify what the mocked object should return by using the when().thenReturn(); method

Question 9

What is busy waiting?

Answer 9

ex: while(!operationComplete)) Note that there is no body to this while loop. Busy waiting is a process synchronization technique in which a process/task waits and constantly checks for a condition to be satisfied before proceeding with its execution. It is not ideal because we are wasting CPU cycles by continuously checking whether the condition is true.

Question 10

How can busy waiting be prevented?

Answer 10

By using awaitility. It doesn’t suffer from busy waiting since it will only periodically check for the condition.

Question 11

What is the difference between verify method and thenReturn method in mocking?

Answer 11

The verify method checks if the specific method was called at all while the thenReturn method allows us to check the behavior of a method by checking if it returns as expected.

Question 12

What is the Corrective Software Maintenance and what is the order in which the phases happen?

Answer 12

This type of maintenance corrects the defects, errors, faults and the order is: implement, test, release.

Question 13

What is the Perfective Software Maintenance and what is the order in which the phases happen?

Answer 13

This type of maintenance adds features to improve features for user experience and the order is: requirements, design, implement, test, release.

Question 14

What is the Adaptive Software Maintenance and what is the order in which the phases happen?

Answer 14

This type responds to changes in environment/context. The order is: design, implement, test, release

Question 15

What is the Preventive Software Maintenance and what is the order in which the phases happen?

Answer 15

This type improves software to reduce risk of deterioration. The order is: design, implement, test, release.

Question 16

What is refactoring?

Answer 16

It is a change in the code that improves readability, structure, efficiency, flexibility without changing the functionality.

Question 17

What are the code smells?

Answer 17

“Smells are surface indications that usually corresponds to a deeper problem in the system.” They are things that are 1)quick to spot 2)smells do not always indicate a problem

Question 18

What does shotgun surgery refer code smell to and how can you refactor that?

Answer 18

Change it one class leads to changes multiple other classes. You can move method/ move field/ combine functions into class/ incline class or method

Question 19

What does the feature envy smell refer to?

Answer 19

Method uses another object’s data more than its own. To refactor it, you can move the method or extract method.

Question 20

What does the data class smell refer to?

Answer 20

Classes with fields but without behavior (no other methods but getters and setters)