The document discusses lambda expressions in Java. It defines a lambda expression as a concise representation of an anonymous function that can be passed around. Lambda expressions allow for passing functions as arguments or returning them. They make code shorter and cleaner compared to anonymous classes. Functional interfaces are required for lambda expressions, where a functional interface defines a single abstract method that lambda expressions can implement.

1. Lambda Expression
Minal Maniar

2.  Lambdas in a nutshell
 Where and how to use lambdas
 The execute around pattern
 Functional interfaces, type inference
 Method references
 Composing lambdas

3.  A lambda expression can be understood as a concise
representation of an anonymous function that can be passed
around: it doesn’t have a name, but it has a list of parameters, a
body, a return type, and also possibly a list of exceptions that can
be thrown. That’s one big definition;
let’s break it down:
 Anonymous— We say anonymous because it doesn’t have an
explicit name like a method would
normally have: less to write and think about!
 Function— We say function because a lambda isn’t associated
with a particular class like a method is.
But like a method, a lambda has a list of parameters, a body, a
return type, and a possible list of
exceptions that can be thrown.
 Passed around— A lambda expression can be passed as argument
to a method or stored in a variable.
 Concise— You don’t need to write a lot of boilerplate like you do
for anonymous classes.

4.  Thus, a lambda expression results in a form of
anonymous class.
 Lambda expressions are also commonly referred
to as closures.
 A functional interface is an interface that
contains one and only one abstract method.
 Thus, a functional interface typically represents
a single action.
 The standard interface Runnable is a functional
interface because it defines only one method:
run( ).
 functional interface defines the target type of a
lambda expression.
 functional interface is sometimes referred to as
a SAM type, where SAM stands for Single Abstract
Method.

5. tomatically
 For example, the following code in (a) can be
greatly simplified using a lambda expression
in (b) in three lines.

6. tomatically

7. Lambda
Parameters
Lambda body
(Apple a1, Apple a2) a1.getWeight().compareTo(a2.getWeight());
Arrow

9. Using lambda expressions, the code is shorter and cleaner. As seen in
this example, lambda expressions may have many variations. You can
handle events by defining handler classes using inner classes,
anonymous inner classes, or lambda expressions. We recommend that
you use lambda expressions because it produces a shorter, clearer, and
cleaner code.
Questions:
1. What is a lambda expression? What is the benefit of using lambda
expressions ? What is the syntax of a lambda expression?
2. What is a functional interface? Why is a functional interface required
for a lambda expression?

10. Oracle Nashorn
Minal Maniar

11.  Oracle Nashorn: A Next-Generation
JavaScript Engine for the JVM by Julien
Ponge
 Nashorn is a JavaScript engine. It is used to
execute JavaScript code dynamically at JVM
(Java Virtual Machine). Java provides a
command-line tool jjs which is used to
execute JavaScript code.
 You can execute JavaScript code by two
ways:
 Using jjs command-line tool, and
 By embedding into Java source code.

12.  Following is the step by step process to
execute JavaScript code at the JVM.
1. Create a file hello.js.
2. Write and save the following code into the file.
(hello.js)

13. 3. Open terminal
4. Write command jjs hello.js and press enter.

14.  You can execute JavaScript file directly from
your Java file. In the following code, we are
reading a file hello.js with the help of
FileReader class.

15. Date/Time API
Minal Maniar

16.  java.util.Date class
 java.sql.Date class
 java.util.Calendar class
 java.util.GregorianCalendar class
 java.util.TimeZone class
 java.sql.Time class
 java.sql.Timestamp class
Formatting Date and Time
 java.text.DateFormat class
 java.text.SimpleDateFormat class

17.  java.time.LocalDate class
 java.time.LocalTime class
 java.time.LocalDateTime class
 java.time.MonthDay class
 java.time.OffsetTime class
 java.time.OffsetDateTime class
 java.time.Clock class
 java.time.ZonedDateTime class
 java.time.ZoneId class
 java.time.ZoneOffset class
 java.time.Year class
 java.time.YearMonth class
 java.time.Period class
 java.time.Duration class
 java.time.Instant class
 java.time.DayOfWeek enum
 java.time.Month enum

18. Stream API
Minal Maniar

19.  Java provides a new additional package in Java 8
called java.util.stream. This package consists of
classes, interfaces and enum to allows
functional-style operations on the elements. You
can use stream by importing java.util.stream
package.
 You can use stream to filter, collect, print, and
convert from one data structure to other etc. In
the following examples, we have apply various
operations with the help of stream.
 Here, we are filtering data by using stream. You
can see that code is optimized and maintained.
Stream provides fast execution.

20. Automatically
 Java The Complete Reference (9th Edition),
Herbert Schildt