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Table of contents
1.
Introduction
2.
Overview of JAVA 8
3.
Top Features of Java 8
4.
Default and Static Methods in Interfaces
4.1.
Code in Java
4.2.
Java
5.
Functional Interfaces and Lambda Expressions
5.1.
Code In Java
5.2.
Java
6.
Java Stream API For Bulk Data Operations On Collections
6.1.
Code In Java
6.2.
Java
7.
forEach() method in the Iterable interface
7.1.
Code In Java
7.2.
Java
8.
Java IO improvements
9.
Java Time API
9.1.
Code in Java
9.2.
Java
10.
Collection API Improvements
10.1.
Code in java
10.2.
Java
11.
Concurrency API Improvements
11.1.
Code in Java
11.2.
Java
12.
Frequently Asked Questions
12.1.
What are the main features of Java 8?
12.2.
What is Java 8 features and why we need it?
12.3.
What is the difference between Java 7 and 8?
12.4.
What are the advantages of Java 8?
13.
Conclusion
Last Updated: Mar 27, 2024
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JAVA 8 features

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Introduction

JAVA 8 was released on 18 March 2014, a major feature release of the development of the JAVA programming language. Java supports the new javascript engine, functional programming, new streaming APIs, etc. Many programmers use JAVA 8 in their projects as it was released with many new features to ensure the ease of the code.

Java 8 features

This article will look at these features in detail to make you understand the JAVA 8 programming language. 

Check out this article - Duck Number in Java and Hashcode Method in Java.

Overview of JAVA 8

JAVA 8 is a significant release of the JAVA programming language. It supports functional programming, a new Javascript engine, and new APIs for time manipulation. This version of Java is the upgradation that provides many changes and new features for a Java programmer.

Some benefits of JAVA 8 are -

  • It provides many  improvements in JAVA IO and the APIs.
     
  • Java 8 provides the packages to deal with the date and time even in a particular zone.
     
  • It also offers many features which help decrease the code's size and optimize it.
     
  • Java 8 provides automatic resource management.
     
  • Java 8 provides functional programming and supports a new javascript engine.
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Top Features of Java 8

JAVA 8 introduces many features in it. 

Some of the JAVA 8 features, which we will discuss in detail, are

  • Default and Static Methods in Interfaces
     
  • Functional Interfaces and Lambda Expressions
     
  • Java Stream API for Bulk Data Operations on Collections
     
  • forEach() method in the Iterable interface
     
  • Java IO improvements
     
  • Java Time API
     
  • Collection API improvements
     
  • Concurrency API Improvements
     

Also read, Swap Function in Java and Java Ioexception

Default and Static Methods in Interfaces

Default and Static methods are the JAVA 8 features used to add a method in each project class by creating a single method in an interface implemented in the class by the 'implements' keyword.

The difference between these keywords is that in the default method, we can override a method's functionality in a particular class. In contrast, static keywords apply the same method in all the classes with an implemented interface.

Below is the implementation of both the methods.

Code in Java

  • Java

Java

import java.util.Optional;

interface School {
default void classStudents()
{
System.out.println("This class is shouting.");
}
static void classTeachers()
{
System.out. println("There are good teachers in this class.");
}
}

class ClassA implements School {
}

class ClassB implements School
{
}

class ClassC implements School
{
@Override
public void classStudents()
{
System.out.println("This class is quiet.");
}
}

class Main {
public static void main(String[] args){

ClassA classAObj = new ClassA();
classAObj.classStudents(); // Calling default method

ClassB classBObj = new ClassB();
classBObj.classStudents(); // Calling default method


ClassC classCObj = new ClassC();
classCObj.classStudents(); // Calling default method
School.classTeachers(); // Calling static method
}
}

 

OUTPUT

Output

 

The above code shows the interface implementation in the classes, and we override the default method in ClassC while we cannot change the static method. Then in the Main class, we call both the methods in the different classes by creating it the Main class.

Also see,  Eclipse ide for Java Developers

Read More,  even number program in java

Functional Interfaces and Lambda Expressions

Functional Interfaces are interfaces that contain one function inside it and the lambda expression is a short block of code that takes the parameter as input and returns the value.

These JAVA 8 features are used to define the abstract method inside the interface in lesser code.

Let's see the implementation of Lambda Expressions in the Functional Interface of this JAVA 8 feature.

Code In Java

  • Java

Java

@FunctionalInterface	// It is optional 
interface School {
public void students();
}

public class Main {
public static void main(String[] args)
{
String s = "Students in schools are lucky";
School sch=()->
{
System.out.println(s);
};
sch.students();
}
}

 

OUTPUT

Output

In the above code, we created a functional interface and a class. In our Main class, we define the class with Lambda's help and print the result in it.

Java Stream API For Bulk Data Operations On Collections

Streams API are Collections Framework related and used to perform bulk operations. These are used to reduce the code. It allows both sequential as well as parallel execution. We use import java.util.stream to use JAVA Stream API.

Below is the implementation of Java Stream API.

Code In Java

  • Java

Java

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Stream;

public class Main {
public static void main(String[] args) {
List<Integer> NaturalNumbers = new ArrayList<>();
for (int i = 0; i <= 20; i++) {
NaturalNumbers.add(i);
}
//List to sequential stream
Stream<Integer> seqStream = NaturalNumbers.stream();

//List of parallel stream
Stream<Integer> parallelStream = NaturalNumbers.parallelStream();

//Lambada in Parallel Stream
String pS = "Parallel Stream";
System.out.println(pS);
Stream<Integer> PNums = parallelStream.filter(k -> k > 15);
PNums.forEach(k -> System.out.println(k));

//Lambada in Sequential Stream
String sS = "Sequential Stream";
System.out.println(sS);
Stream<Integer> SNums = seqStream.filter(k -> k > 15);
SNums.forEach(k -> System.out.println(k));
}
}

 

OUTPUT

Output

 

The above code is written in Java in which we created a list of natural numbers from 1 to 20, then created a list of Parallel and Sequential streams and printed both the list with the help of Lambada.

We observe the sequence in the parallel stream is random, while in the sequential stream, the printed numbers are in a particular series.

forEach() method in the Iterable interface

JAVA 8  provides a new feature to traverse the elements. The forEach loop is used in the Iterable and Stream interface. Below is the code which shows the implementation of forEach loop.

Code In Java

  • Java

Java

import java.util.*;
public class Main
{
public static void main(String[] args)
{
List<String> ClassA = new ArrayList<String>();
ClassA.add("Shivam");
ClassA.add("Shristy");
ClassA.add("Vardaan");
ClassA.add("Utkarsh");
ClassA.forEach(Students -> System.out.println(Students));
}
}

 

OUTPUT

Output

In the above we create a list in which we add some elements, and then we use a forEach loop to print the name of all the elements added to the list.

Java IO improvements

JAVA 8 improves the performance of input-output packages like java.lang.String.getBytes() and the constructors like java.lang.String.

Some IO improvements are Files.list(Path dir) that returns a lazily populated Stream, Files.lines(Path path) which help to read all the lines from the file, Files.find() that searches for files in a file tree and BufferedReader.lines() which helps to read the lines from the BufferReader.

The size of the charsets.jar in <JDK_HOME>/jre/lib/ is decreased compared to the previous version.

Java Time API

Previously it was challenging to work with date and time in the Java project, as there were no standard approach to deal with it but there is an introduction to java.time package, which helps to work with the time in a project. 

Packages like java.time.zone are used to work according to the time zones and java.time.format provides the class to print and parse the dates and time.

This is one of the most important JAVA 8 features. Below is the example to learn the implementation of this package.

Code in Java

  • Java

Java

import java.time.*;
class Main {
public static void main(String[] args) {
LocalDate TodayDate = LocalDate.now();
System.out.println("Today's Date is: " + TodayDate);

LocalTime TimeNow = LocalTime.now();
System.out.println("Time is: " + TimeNow);
}
}

 

Output

Output

 

In the above code, we import the java.time.* package and print the current date and time as the output.

Collection API Improvements

We had already seen the forEach() methods for collections. Similarly, many methods are introduced in JAVA 8 features.

Some of them are default method removeIf(Predicate filter) collections to remove the elements based on some conditions, and some more are Map replaceAll()compute(), and merge() methods.

This version also improves the performance of the HashMap class with Key Collisions.

Let’s take an example of removeIf() method to remove some of the elements from a list. 

Code in java

  • Java

Java

import java.util.*;
class Main
{
public static void main(String[] args)
{
List<Integer> List = new ArrayList<>();
List.add(17);
List.add(23);
List.add(9);
List.add(21);
List.add(15);


List.removeIf(n -> (n > 20));
for (int marks : List)
{
System.out.println(marks);
}
}
}

 

Output

Output


The above code creates a list, adds some elements, then removes some elements satisfying the particular condition, and prints the resulting list. 

Concurrency API Improvements

There are some inbuilt methods made to enhance API. Some of these methods are compute(), forEachEntry(), forEachKey(), forEachValue(), merge(), reduce(), search(), forEach() etc. Other methods, like mappingCount and newKeySet, have also been added.

Two new interfaces are also introduced by java.util.concurrent package in which one creates a stage of asynchronous computation while others identify asynchronous tasks produced by async methods.

Let’s see a code in java to implement forEachKey() for concurrentHashMap.

Code in Java

  • Java

Java

import java.util.concurrent.ConcurrentHashMap;
class Main {
public static void main(String[] args) {
ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
map.put("Utkarsh", 1);
map.put("Sri", 2);
map.put("Shiv", 3);
map.put("Varda", 4);
map.put("Varnit", 5);

map.forEachKey(1, k -> k.length(), System.out::println);
}
}

Output

Output

The above code shows the use of forEachKey() in HashMap, in which we created a concurrentHashMap and the length of each key in the map.

Frequently Asked Questions

What are the main features of Java 8?

Lambda expressions, the Stream API for functional-style operations on collections, the Java.time package for date and time handling, default methods in interfaces, and the Optional class for more robust null handling are just a few of the notable features introduced by Java 8.

What is Java 8 features and why we need it?

Lambda expressions, Stream API, Java.time for date handling, default interface methods, and Optional classes are among the Java 8 features. These improve Java programming's readability, conciseness, and performance, increasing developer productivity.

What is the difference between Java 7 and 8?

Modern programming features were added to Java 7 by introducing lambda expressions, the Stream API for functional programming, java.time for date handling, default methods in interfaces, and the Optional class in Java 8.

What are the advantages of Java 8?

The Stream API for functional-style operations, Java.time for better date handling, default methods for interface evolution, and Lambda expressions for concise code are some benefits of Java 8.

Conclusion

In this article, we saw about JAVA 8 features with some overview of JAVA 8. These JAVA 8 features make writing code and doing significant projects easy and short. JAVA 8 provides various methods and APIs, which make the JAVA 8 special.

JAVA 8  features make the JAVA be used in more companies than before. Some features like Time API and Lambada make a considerable change in JAVA.

To learn more about JAVA 8, go through the below topics

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