To create a circle in Java there are various functions available. These are the fillOval() function, the drawRoundRect() function, and the draw() function

## How to Pad a String with Zeros or Spaces in Java

A string is padded with zeros or spaces by using methods like leftPad or padStart using classes from external libraries like Apache Commons or Guava library

## How to Calculate the Distance Between Two Points in Java

To calculate the distance between two points in Java, use the “Math.sqrt((a2-a1)*(a2-a1) + (b2-b1)*(b2-b1));” equation/formula.

## How to Implement getActiveCount() Method of ThreadPoolExeceutor in Java

In Java, the getActiveCount() method is responsible for providing the number of tasks that are currently/actively running.

## How to Implement a Generic Graph in Java

Generic graphs can be implemented with generic classes and HashMaps. They can store data of different types, such as int, string, custom objects, etc.

## How to Use Optional.ofNullable() Method in Java

Optional.ofNullable() Method in Java is used for the implementation of both null and not null values. The optional.empty() method appears for the null values

## How to Implement a Java Callback Function

To implement a callback function in Java, the approach involves creating a function as a first-class entity, which is then invoked from a second class.

## How to Handle Covariant Return Type in Java

The covariant return type in Java deals with non-primitive data types like arrays, lists, and classes. It makes the code look cleaner and more usable.