java 8 is a major feature release of java programming language development. its initial version was released on 18 march 2014. with the java 8 release, java provided supports for functional programming, new javascript engine, new apis for date time manipulation, new streaming api, etc.

new features

• 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.

consider the following code snippet.

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));
   }
}

run the program to get the following result.

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.