Senior Software Engineer

Functional programming moves more basic programming ideas into the compiler, ideas such as list comprehensions and caching.
The biggest benefit of Functional programming is brevity, because code can be more concise. A functional program doesn't create an iterator variable to be the center of a loop, so this and other kinds of overhead are eliminated from your code.
The other major benefit is concurrency, which is easier to do with functional programming because the compiler is taking care of most of the operations which used to require manually setting up state variables (like the iterator in a loop).

A Wrapper class is a class whose object wraps or contains primitive data types. When we create an object to a wrapper class, it contains a field and in this field, we can store primitive data types. In other words, we can wrap a primitive value into a wrapper class object.
Need of Wrapper Classes : 
They convert primitive data types into objects. Objects are needed if we wish to modify the arguments passed into a method (because primitive types are passed by value).
The classes in java.util package handles only objects and hence wrapper classes help in this case also.
Data structures in the Collection framework, such as ArrayList and Vector, store only objects (reference types) and not primitive types.
An object is needed to support synchronization in multithreading.

An InterruptedException is thrown when a thread is interrupted while it's waiting, sleeping, or otherwise occupied. In other words, some code has called the interrupt() method on our thread. It's a checked exception, and many blocking operations in Java can throw it.

Join method in Java allows one thread to wait until another thread completes its execution. In simpler words, it means it waits for the other thread to die. It has a void type and throws InterruptedException. Joining threads in Java has three functions namely,
join()
join(long millis)
join(long millis, int nanos)

Steps : 
1) Declare the class as final so it can’t be extended.
 

2) Make all fields private so that direct access is not allowed.
 

3) Don’t provide setter methods for variables.
 

4) Make all mutable fields final so that its value can be assigned only once.
 

5) Initialize all the fields via a constructor performing deep copy.
 

6) Perform cloning of objects in the getter methods to return a copy rather than returning the actual object reference.

In Java, the Try-with-resources statement is a try statement that declares one or more resources in it. A resource is an object that must be closed once your program is done using it. For example, a File resource or a Socket connection resource. The try-with-resources statement ensures that each resource is closed at the end of the statement execution. If we don’t close the resources, it may constitute a resource leak and also the program could exhaust the resources available to it.
You can pass any object as a resource that implements java.lang.AutoCloseable, which includes all objects which implement java.io.Closeable.

Spring Boot can help you to quickly build any applications without having to worry about their safe and correct configuration. ⠀
Spring Boot has a huge user community which means you can find free learning materials and courses. Spring Boot is multi-threaded. This is useful when performing long or repetitive operations. When the main thread is consumed, others are used concurrently.
Reduces the time spent on development and increases the overall efficiency of the development team.
Helps to autoconfigure all components for a production-grade Spring app.
Facilitates the creation and testing of Java-based applications by providing a default setup for unit and integration tests.
Helps to avoid all the manual work of writing boilerplate code, annotations, and complex XML configurations.
Comes with embedded HTTP servers like Jetty and Tomcat to test web applications.
The integration of Spring Boot with the Spring ecosystem which includes Spring Data, Spring Security, Spring ORM, and Spring JDBC is easy.

There are mainly 3 advantages of generics. They are as follows:

1) Type-safety: We can hold only a single type of objects in generics. It doesn't allow to store other objects.
2) Type casting is not required: There is no need to typecast the object.
3) Compile-Time Checking: It is checked at compile time so problem will not occur at runtime. The good programming strategy says it is far better to handle the problem at compile time than runtime.