New features of Java 1.8 (Java 8)

New features of Java 8

1. Lamda Expressions

It reduces the code, such as in an anonymous inner class.

Example 1 (Before Java 8)

Runnable oldRunner = new Runnable(){

    public void run(){

        System.out.println("I am running");

    }

};

Example 1 (After Java 8)

Runnable java8Runner = () ->{

    System.out.println("I am running");

};

Example 2 (Before Java 8)

Comparator c = new Comparator() {

    public int compare(Object a, Object b) {

        return Integer.compare(a.length(), b.length());

   }

}

Example 2 (After Java 8)

Comparator c = (a, b) -> Integer.compare(a.length(), b.length());

2. Streams collection types

A stream represents a sequence of elements and supports different kind of operations.

Lists and Sets support new methods stream() and parallelStream() to either create a sequential or a parallel stream. Parallel streams are capable of operating on multiple threads.

List<String> myList = Arrays.asList("a1", "c1", "b1", "b2", "c2");

myList

    .stream()

    .filter(s -> s.startsWith("c"))

    .map(String::toUpperCase)

    .sorted()

    .forEach(System.out::println);

// C1

// C2

3. Functional Interfaces

These interfaces can contain some default methods which need not be implemented and can run directly from the interface.

4. Date/Time changes

The Date/Time API is moved to java.time package and Joda time format is used.

Most classes are Threadsafe and immutable.

5. Nashorn - Run JS on JVM

This is the javascript engine that enables us to run javascript to run on a  jvm.

It is compatible with Node.js applications while also allowing actual Java libraries to be called by the javascript code running on server.

6. StringJoiner

Utility method to construct a string with desired delimiter

StringJoiner strJoiner = new StringJoiner(",");
strJoiner.add("Hello").add("Bye");
System.out.println(strJoiner);

// Hello,Bye

Others

• Reflection API now support TypeName, GenericString, etc.
• Comparator methods like reversed, comparing and thenComparing have been added which allow easy customization of comparison of multiple fields.