Java 8 - Overview

JAVA 8 (aka jdk 1.8) is a major release of JAVA programming language development. Its initial version was released on 18 March 2014. With the Java 8 release, Java provided support for functional programming, new JavaScript engine, new APIs for date time manipulation, new streaming API, etc.

New Features

There are dozens of features added to Java 8, the most significant ones are mentioned below −

• Lambda expression − Adds functional processing capability to Java.
• Method references − Referencing functions by their names instead of invoking them directly. Using functions as parameter.
• Default method − Interface to have default method implementation.
• New tools − New compiler tools and utilities are added like ‘jdeps’ to figure out dependencies.
• Stream API − New stream API to facilitate pipeline processing.
• Date Time API − Improved date time API.
• Optional − Emphasis on best practices to handle null values properly.
• Nashorn, JavaScript Engine − A Java-based engine to execute JavaScript code.

Along with these new featuers, lots of feature enhancements are done under-the-hood, at both compiler and JVM level.

Programming Style

Java 8 is expected to change the way programmers code their programs. For a brief comparison between Java 7 and Java 8, let us see a sorting program written with both Java 7 and Java 8 syntaxes.

import java.util.Collections;
import java.util.List;
import java.util.ArrayList;
import java.util.Comparator;

public class Java8Tester {
   public static void main(String args[]){
   
      List<String> names1 = new ArrayList<String>();
      names1.add("Mahesh ");
      names1.add("Suresh ");
      names1.add("Ramesh ");
      names1.add("Naresh ");
      names1.add("Kalpesh ");
  
      List<String> names2 = new ArrayList<String>();
      names2.add("Mahesh ");
      names2.add("Suresh ");
      names2.add("Ramesh ");
      names2.add("Naresh ");
      names2.add("Kalpesh ");
  
      Java8Tester tester = new Java8Tester();
      System.out.println("Sort using Java 7 syntax: ");
  
      tester.sortUsingJava7(names1);
      System.out.println(names1);
      System.out.println("Sort using Java 8 syntax: ");
  
      tester.sortUsingJava8(names2);
      System.out.println(names2);
   }
   
   //sort using java 7
   private void sortUsingJava7(List<String> names){   
      Collections.sort(names, new Comparator<String>() {
         @Override
         public int compare(String s1, String s2) {
            return s1.compareTo(s2);
         }
      });
   }
   
   //sort using java 8
   private void sortUsingJava8(List<String> names){
      Collections.sort(names, (s1, s2) -> s1.compareTo(s2));
   }
}

This program should yield the following output −

Sort using Java 7 syntax:
[ Kalpesh Mahesh Naresh Ramesh Suresh ]
Sort using Java 8 syntax:
[ Kalpesh Mahesh Naresh Ramesh Suresh ]

Here the sortUsingJava8() method uses sort function with a lambda expression as parameter to get the sorting criteria.
These all features are packed right into Java 8, we do not need to install anything other than Java 8.