DEV Community: Sivaram Rasathurai

Remove Java Developers NullPointerException Hell

Sivaram Rasathurai — Mon, 24 Jan 2022 16:33:18 +0000

NullUtil.executeViaNullSafer method will execute the given function on Non-Null Values and, when the value is null It will return Null instead of executing the function.
NullUtil.executeExecutorOrDefault method will execute the given function on Non-Null Values and, If the value is null, It will return the given default value.
NullUtil.executeMutator method mutates the reference type values without returning anything. If the value is null, It will not do anything.
NullUtil.replaceNull method will replace the null value with the given defaultValue. when the value is not null, It will return the value.
NullUtil.hasText method is used to check the String value has any kind of text or not
.
NullUtil.trimValue method will be used to trim the String without causing the null pointer Exception.

More details about this Util class you can find on my medium article(https://rcvaram.medium.com/remove-dirty-nullchecks-in-java-8aca833dc276) or my stackoverflow answer(https://stackoverflow.com/a/70200959/12894468).

Answer: Best way to check for null values in Java? How many time you have written null check

Sivaram Rasathurai — Thu, 02 Dec 2021 15:11:09 +0000

answer re: Best way to check for null values in Java?

Dec 2 '21

Generic Method to handle Null Values in Java

If that object is not null we are going to do the following things.

a. We can mutate the object (I)

b. We can return something(O) as output instead of mutating the object (I)

c. we can do both

In this case…

Open Full Answer

Answer: What is aplha-trimmed mean filter?

Sivaram Rasathurai — Wed, 18 Aug 2021 04:06:45 +0000

answer re: What is aplha-trimmed mean filter?

Sep 18 '20

This filter is a combination of mean filter and median filter as you said First, we look at where we can use this filter. It performs reasonably well in the presence of both Gaussian and outlier noise.

This is an algorithmic approach that tries to combine properties of the mean…

Open Full Answer

Answer: Difference between Encapsulation and Abstraction

Sivaram Rasathurai — Wed, 04 Aug 2021 05:03:39 +0000

answer re: Difference between Encapsulation and Abstraction

Jan 2 '21

Yes If I say Encapsulation is a kind of an advanced specific scope abstraction,

How many of you read/upvote my answer. Let's dig into why I am saying this.

I need to clear two things before my claim.

One is data hiding and, another one is the abstraction

…

Open Full Answer

Answer: What is the best way to repeatedly execute a function every x seconds? [closed]

Sivaram Rasathurai — Wed, 04 Aug 2021 05:02:04 +0000

answer re: What is the best way to repeatedly execute a function every x seconds?

Nov 30 '20

Alternative flexibility solution is Apscheduler.

pip install apscheduler

from apscheduler.schedulers.background import BlockingScheduler
def print_t()
  pass

sched = BlockingScheduler()
sched.add_job(print_t, 'interval', seconds =60) #will do the print_t work for every 60 seconds

sched.start()

Also, apscheduler provides so many schedulers as follow.

BlockingScheduler: use when the scheduler is the only thing…

Open Full Answer

Answer: Detect if there is gray color in image by opencv Python

Sivaram Rasathurai — Wed, 04 Aug 2021 05:01:21 +0000

answer re: Detect if there is gray color in image by opencv Python

Sep 24 '20

The better way is to change the colour space into HSV and find the Hue value range for colour.

Take each frame of the video
Convert from BGR to HSV color-space
Threshold the HSV image for a range of blue colour

Below code is from OpenCV official site to detect…

Open Full Answer

Answer: What's a monitor in Java?

Sivaram Rasathurai — Sun, 18 Jul 2021 15:34:05 +0000

answer re: What's a monitor in Java?

Sep 29 '20

In concurrent programming, we need to focus on two things

Mutual exclusion

When a process/thread is executing its critical section no other processes are allowed to execute their critical section. (Each process has a code segment called "Critical section" in which shared data is accessed.)

Synchronisation

When threads are trying…

Open Full Answer