The document outlines a course on Android programming with Java, covering topics such as nested classes, lambda expressions, multithreading, and socket programming. It explains nested classes, including static nested classes, inner classes, local classes, and anonymous classes, along with their syntax and examples. Additionally, it introduces lambda expressions and their syntax, details multithreading concepts, and describes the basics of socket programming for application communication.

1. ANDROID COURSE
WITH JAVA
Developed by Keroles Magdy
keroles.m.yacoub@gmail.com
2019 ©

2. Session topics :-
• Nested Classes in Java.
• Lambda Expressions.
• Multithreading.
• Socket Programming.

3. Nested Classes in Java :-
• Nested Classes in Java, it means define a class within another class.
• It is useful for encapsulation, create more readable and maintainable code.
Nested Class
Nested Class
Inner Class
(Non-static
nested class
Local
Classes
Anonymous
Classes

4. Nested Classes in Java :-
• Static Nested Class : cannot refer directly to instance variables or
methods defined in its enclosing class: it can use them only through an
object reference.
• Syntax : OuterClass.StaticNestedClass nestedObject = new
OuterClass.StaticNestedClass();
• inner class : to instantiate an inner class, you must first instantiate the
outer class. Then, create the inner object within the outer object.
• Syntax : OuterClass.InnerClass innerObject = outerObject.new
InnerClass();

5. Nested Classes in Java :-
• Static Nested Class.
• EX :
class OuterClass
{
int outer_y = 20;
static class StaticNestedClass
{
void display() { System.out.println("outer_y = " + outer_y); }
}
}

6. Nested Classes in Java :-
• Calling :
public static void main(String[] args)
{
OuterClass.StaticNestedClass nestedObject = new
OuterClass.StaticNestedClass();
nestedObject.display();
}

7. Nested Classes in Java :-
• Local Inner Classes.
• EX :
class OuterClass
{
int outer_y = 20;
class InnerClass
{
void display() { System.out.println("outer_y = " + outer_y); }
}
}

8. Nested Classes in Java :-
• Calling :
public static void main(String[] args)
{
OuterClass outerObject = new OuterClass();
OuterClass.InnerClass innerObject = outerObject.new InnerClass();
innerObject.display();
}

9. Nested Classes in Java :-
• Anonymous class, is an inner class without a name and for which only a
single object is created.
• EX :
Age A1= new Age() {
@Override
public void getAge() {
System.out.print("Age is "+x);
}
};

10. Break

11. Lambda Expressions :-
• Lambda expressions, express instances of functional interfaces (An
interface with single abstract method is called functional interface).
• lambda expressions are added in Java 8.
• Syntax :
(int arg1, int arg2) -> {System.out.println(“Sum =“+(arg1+arg2));}
Arrow token
Body of Lambda expression
( body )
Argument List
(lambda operator)

12. Lambda Expressions :-
• EX :
• Zero parameter:
() -> {System.out.println("Zero parameter lambda");}
• One parameter:
(p) -> {System.out.println("One parameter lambda" +p);}
• Multiple parameters:
(p1,p2) -> {System.out.println("Multiple parameters lambda" +p1+ " " +p2);}

13. Multithreading :-
• Thread, allows concurrent execution of two or more process simultaneously.
• It doesn't block the user because threads are independent and you can
perform multiple operations at the same time.
• Threads can be created by using two mechanisms :
1. Extending the Thread class.
2. Implementing the Runnable Interface.

14. Multithreading :-
• EX:
class Multi extends Thread{
public void run(){
System.out.println("thread is running...");
}
public static void main(String args[]){
Multi t1=new Multi();
t1.start();
}
}

15. Multithreading :-
• EX:
class Multi3 implements Runnable{
public void run(){
System.out.println("thread is running...");
}
public static void main(String args[]){
Multi3 m1=new Multi3();
Thread t1 =new Thread(m1);
t1.start();
}
}

16. Socket Programing :-
• Java Socket programming is used for communication between the
applications running on different JRE.
• Socket and ServerSocket classes are used for connection-oriented socket
programming
Server Port Client Port

17. Socket Programing :-
• one-way client and server communication

18. the End