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Topics in Enterprise Architecture

07MCA41

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UNIT- I

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Introduction to JAVAJava is a programming language originally developed by Sun

Microsystems and released in 1995 as a core component of Sun

Microsystems Java platform. The language derives much of its

syntax from C and C++ but has a simpler object model and fewer

low-level facilities. Java applications are typically compiled to

bytecode (class file) that can run on any Java Virtual Machine (JVM)regardless ofcomputer architecture.

Java was initially called as OAK later it was renamed as JAVA

in

the year 1995.

Write Once Run Anywhere

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Editions of Java

1.) Java SE2.) Java EE

3.) Java ME

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JDK(Java Development Kit)1.) Java Loader2.) Javac - Compiler

3.) JAR Java ARchiver

4.) Jdb Java Debugger

5.) Javap Class file Disassembler6.) Javah C header and stub generator

7.) Applet viewer

8.) Javaws Java Web Start

9.) Javadoc Java Documentation

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Java Applications1.) Mobiles

2.) Games

3.) Blu Ray Disc

4.) NASA5.) Web Sites

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Creating, Compiling and Executing a Java Program

Create / Modify Source code

any compilation errors

Compile Source code

Bytecode

Run Byte code

Result

Source code

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JVM(Java Virtual Machine)A Java Virtual Machine (JVM) is a set of computer

software programs and data structures that use a

virtual machine model for the execution of other

computer programs and scripts. The model used by a

JVM accepts a form of computer intermediate

Language commonly referred to as Java bytecode .

JVM is an Interpreter for bytecode. Translating a Java

program into bytecode makes it much easier to run a

program in a wide variety of environments.

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JVM(Java Virtual Machine)

In Java a program will be written once and thesource program can be compiled into a special

type of machine language code known as

bytecode.

Any

Computer

JVM

Java Bytecode

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JVM Architecture

Class loader

subsystem

PC

Registers

Java

StacksHeapMethod

Area

Native Method

InterfaceExecution

Engine

Native Method

Stack

Class files

Native method libraries

Runtime Data Area

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Java Buzzwords or Features

1.) Simple2.) Secure

3.) Portable

4.) Object Oriented

5.) Robust

6.) Multithreaded

7.) Architecture Neutral

8.) Interpreted & High Performance10.) Distributed

11.) Dynamic

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A Simple Program in Java

import java.io.*;class Simple

{

public static void main(String args[]){

System.out.println(a simple program);

}

}

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Compilation of Java Program

1.) After writing the source code

2.) Save it with .java extension.

3.) To Compile:-

javac pgmname.java

4.) Execution or Interpreting or Running:-

java pgmname or classname

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Polymorphism

Static Dynamic(Method Overloading) (Method Overriding)

1.)Static /(Early Binding)/(Compile Time)2.) Dynamic/(Late Binding)/(Run Time)

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Datatypes and Other Tokens, Boolean Variables

Datatypes

Integers Floating-point Characters BooleanByte Float Char Boolean

Int Double

Shortlong

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Datatypes and Sizes

Datatypes Width(in Bits)1.)Long 64(8)

2.)Int 32(4)

3.)Short 16(2)

4.)Byte 8 (1)

5.)Double 64(8)

6.)Float 32(4)7.)Char 16(2)

8.)Boolean True/False

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Identifiers, LiteralsI

dentifiers in Java are used as:-(i) Class Names

(ii) Method Names

(iii) Variable Names

Literals:-

Any constant value in java is created by using

a literal representation.

E.g:- int a=100; char c=x

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TokensIn a Java program, all characters are grouped into symbols called tokens.

There are six kinds of Tokens available in Java. Each Token should be

identified in Java programs.

Token

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OOP ( Object Oriented Programming)

1.) Encapsulation2.) Inheritance

3.) Polymorphism

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Access Specifiers

Private No Modifier Protected Public

Same Class Yes Yes Yes Yes

Same Package

Subclass

No Yes Yes Yes

Same Package

non subclass

No Yes Yes Yes

Different

Package

Subclass

No No Yes Yes

Different

Package non

Subclass

No No Nos Yes

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StreamsThere are Two types of Streams:-1.) Byte Streams

2.) Character Streams

InputStream

Byte Stream Classes

OutputStream

Reader

Character Stream Classes

Writer

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Streams

Input Stream ------------------------- System.in

Print Stream -----------System.out, System.err

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Streams

Buffer Java Program

Output

Input

Print()

Println()

Input StreamReader

Readline()

Read()

Buffered Reader

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Control StatementsControl Statements

Selection(conditional) Iteration(loops) Jump

if For Return

Nested ifs While Break

if-else-if Dowhile Continue

SwitchNested Switch

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Type Conversion and Type CastingRules are:-

1.) The two types should be compatible

2.) The destination type should be larger than the

source type Range increases

Byte, short, int, long, float, double

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Java Escape SequencesCharacterEscapeSequence Name

\b Backspace

\t Tab

\n Linefeed\f Formfeed

\r Carriage Return

\\ Backslash

\ Single Quote\ Double Quote

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Operators and ExpressionsOperator Result

+ Addition- Subtraction

* Multiplication

/ Division

% Modulus++ Increment

+= Addition Assignment

-= Subtraction Assignment

*= Multiplication Assignment/= Division Assignment

%= Modulus Assignment

-- Decrement

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Bitwise OperatorsOperator Result~ Bitwise unary NOT

& Bitwise AND

| Bitwise OR

^ Bitwise exclusive OR

>> Shift right>>> Shift right zero fill

>= Shift right assignment

>>>= Shift right zero fill assignment

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Relational OperatorsOperator Result

== Equal to

!= Not equal to

> Greater than

< Less than>= Greater than or equal to

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Boolean Logical OperatorsOperator Result

& Logical AND| Logical OR

^ Logical XOR( exclusive OR)

|| Short circuit OR

&& Short circuit AND

== Equal to

!= Not equal to

! Logical Unary NOT

&= AND assignment

|= OR assignment

^= XOR assignment

?: Ternary if-then-else

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The Assignment Operator

Var=expression;e.g:- int a,b,c;

a=b=c=54;

The ? Operator:- (Ternary Operator)Expression ? Expression2 : Expression3

Operator Precedence.Highest:-

(),[],.,++,--,~,!,*,/,%,+,-,>>,>>>, =,

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String HandlingMethods in String Handling are:-1.)length();

2.)concat();

3.)toString();

Character Extraction Methods:-1.)charAt();

2.)getChars();

3.)getBytes();

4.)toCharArray();

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String Handling

String Comparison Methods are:-1.)equals() and equalsIgnoreCase()

2.)regionMatches()

3.)startsWith() , endsWith()4.)compareTo()

Searching of Strings:-1.)indexOf()

2.)lastIndexOf()

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String Handling

Modifying a String:-1.)substring()

2.)concat()

3.)replace()

4.)trim()

Data conversion using valueOf().

Changing the case of characters with in a

String:-1.)toLowerCase()

2.)toUpperCase()

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II -UNIT

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ClassesA Class is a Template for an Object, anObject is an instance of a Class.

The base class for all classes in Java isObject Class. All other classes are

subclasses of Object class. The Object

class defines few methods, that impliesthey are available in every object.

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ClassesSyntax:-

Class classname{type instance-variable1;

type iv2;

type methodname1(){ }

type methodname2(parameter-list)

{ }

}

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Object Class

Method Purpose1.)Object clone() - creates a new objectsame as the object being cloned.

2.)boolean equals(Object object)checkswhether one object is equal to another.

3.)void finalize() - called before an unusedobject is recycled.

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Object ClassMethod Purpose

4.)Class getClass() Obtains the class of anobject at run time.

5.) int hashCode() Returns the hashcodeassociated with the invoking object.

6.) void notify() - Resumes execution of athread waiting on the invoking object.

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7.) void notifyAll() - Resumes execution of all

threads waiting on the invoking object.

8.)String toString() Returns a string thatdescribes the object.

9.)void wait()10.)void wait(long milliseconds)

11.)void wait(long milliseconds, int nanoseconds)

waits on another thread of execution

Object ClassMethod Purpose

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ConstructorsA class contains constructors that are invoked to

create objects from the class blueprint. Constructor

declarations look like method declarationsexcept

that they use the name of the class and have no

return type.As with methods, the Java platform differentiates

constructors on the basis of the number of

arguments in the list and their types. we cannotwrite two constructors that have the same number

and type of arguments for the same class, because

the platform would not be able to tell them apart.

Doing so causes a compile-time error.

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You don't have to provide any constructors for your

class, but you must be careful when doing this. The

compiler automatically provides a no-argument,

default constructor for any class without constructors.

This default constructor will call the no-argument

constructor of the superclass. In this situation, the

compiler will complain if the superclass doesn't havea no-argument constructor so you must verify that it

does. If your class has no explicit superclass, then it

has an implicit superclass of Object, which does have

a no-argument constructor.You can use access modifiers in a constructor's

declaration to control which other classes can call the

constructor.

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Rules for Constructors:-1.) Constructors can use any access modifier,

including private.

2.) the constructor name must match the

name of the class.3.)constructors must not have a return type.

4.)A method will have a return type but

constructor will not have any return type.

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E.g:- Constructor

1.)class Foo

{

Foo()

{ }

}

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2.)class Foo

{

int size;

String name;Foo(String name,int size)

{

this.name=name;

this.size=size;

}

}

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Method Overloading

When a class has more than one methodwith same name but with different

parameters we call it as Method

Overloading.

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Method Overriding

When a method in the subclass has the samename and type signature as a method in the

super class than the method in the subclass is

said to be as over ridden method.

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ArraysAn array is used to store a collection of data.It is a collection of homogeneous elements.

Array is used to store a fixed size sequential

collection of elements of the same type.

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PackagesA Package is a container for a group of classesthat are used to keep the class name space

compartmentalized. They are stored in a

hierarchical manner and are explicitly imported

into new class definitions.

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PackagesHierarchy of Packages in Java:-

Java

Lang Util IO AWT

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Packages

1.)When the programs are with in the package tocompile we have to specify at that package level

a.)javac *.java

b.)Java class name(where main method exists)

2.) When main method is outside the package

Compile with in the package but run or execute

the program outside the package.

3.)To create the package

javac d . Clsname .java

While compiling:- java pkgname.clsname

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Abstract Methods

A Method with complete body is called as ConcreteMethod, with out body is called as Abstract

Method. Methods which are incomplete are called

as Abstract Methods.

A class which contains Abstract Methods

must be declared as Abstract which is a keyword in

Java. By using Abstract methods we cannot create

any objects only references can be created.

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Abstract Methods

Notation:-abstract class A

{

abstract void m1();

void m2()---- Concrete Method

{ }

}

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InterfacesIn Interfaces all the methods must be Abstract

Methods. Interfaces are syntactically similar to

classes but all the methods are declared with out

body.

Interfaces are declared by using Interface keyword.Once the interfaces are defined any number of

classes cam implement that interface.

By default all the methods in interface are public,

abstract.

By default all the variables in interface are static,

final.

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InterfacesJava allows only single inheritance for class

extension, but multiple extensions for interfaces.

E.g:-

Public class Newclass extends Baseclass

implements Int1,Int2

.. Intn

An interface can inherit other interfaces using the

extends keyword such an interface is called as a

subinterface.

E.g:- interface iface3 extends iface1,iface2.ifacen

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Interfaces

E.g:-Interface iface1

{

void method1();

void method2();

}

Class A implements iface1

{public void method1(){}

public void method2(){}

}

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Differences - Interfaces and Abstract Classes

1.)All the methods in interface are abstract

methods where as abstract classes can

contain both abstract methods and concrete

methods.

2.) In interfaces all the variables are by default

public, static and final where as in abstract

classes we have to declare explicitly.

3.)In interfaces all methods are by defaultpublic and abstract where as in abstract

classes we have to explicitly declare the

methods as abstract.

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Exception Handling

An Exception is an abnormal condition thatdisturb the normal program flow execution.

Difference between Error and Exception is

Error signify drastic failures which cannot behandled by the programmer.

E.g:- Stack Overflow

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Exception Handling

Throwable

Error Exception

Checked Unchecked

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Exception

CheckedExceptions UncheckedExceptionsIOException NullPointerException

ClassNotFound ArrayIndexOutOfBounds

CloneNotSupported ArithMeticExceptionNoSuchMethod ClassCastException

NoSuchFieldException

SQLException

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Exception HandlingDifferent types of exceptions available in Java

are :-

1) ArithmeticException

ex:- division by zero

2)IOException :- which are frequently occured at

Input Output Operations time.

3) ArrayIndexOutofBounds:-Occurs when you

are trying to access the element whose index is

greater than length of our array.

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Exception Handling

4) NullPointerException:-Occurs when you aretrying to perform operations on the values not

yet initialized.

5) StringIndexOutofBounds:- Same as

ArrayIndexOutofBounds

6) FileNotFoundException:- If you are trying toaccess the file which is not available.

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Exception Handling7)NumberFormatException:- Occurs when we

are trying to assign value to the variable which is

of different type.

8)ClassNotFoundException:- If the accesing classis not available in the current directory.

9)NoSuchMethodException:- Occurs when you

call the method which is not available in the

current class.

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Exception HandlingException Handling in Java is managed by Fivekeywords:-

1.)try

2.)catch3.)throw

4.)throws

5.)finally

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INNER CLASSESInner classes are also called as Nested classes. It is a classwhich is declared in another class.

Some properties ofInner classes are:-

1.)We can use the classname only with in the defined scope,the name of the inner class must be different from the outer

class.

2.)the inner class can use both class and instance variables

of enclosed classes and final local variables of enclosingblocks.

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INNER CLASSES

3.)the inner class can be defined as abstract.

4.)the inner class can have any access specifier.

5.)the inner class can act as an interface

implementer.

6.)Same type of variables can be called from

both inner and outer classes.

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Applets

Applets are small applications that areaccessed on an Internet server, transported

over the Internet, automatically installed,

and run as a part of a web document.

Applets are created to distribute Java code

they are default GUI's. They will be loaded as

documents which can be executed eitherusing the Browser or AppletViewer utility.

A l t

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AppletsLife Cycle of an Applet:-

Init()

Start()

paint()

Stop()

destroy()

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AppletsWhen applet is loaded for the first time the init()method is going to be invoked from there the

flow will be transferred to the start() which

executes the paint() if exists.If Applet got focus the start() is going to be

executed, the stop() is going to be executed when

ever the focus lost.

If Applet is terminated the Stop() and destroy()are going to be executed.

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Applets

1.)init()- The init() is invoked after the applet iscreated. If a subclass of Applet has an initialization

to perform, it should override this method. It is the

first method called in every Applet.

2.)start()- The start() is invoked after the init(). It is

also called when user returns to the Web page

containing the applet after surfing the pages.

3.)stop()- The stop() is invoked when user leaves

the page.

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Applets4.)destroy()- the destroy() is invoked when the

browser exits normally to inform the applet

that it is no longer needed and should release

any resources it has allocated.

Applets are Event Driven. The

execution of an Applet will not start with main

method.

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Applets

Two types of applets are:-1.)Applet Class(which uses AWT)

2.)Swing Class(JApplet)

AWT-stands for Abstract WindowToolkit. AWT components can be

decorated directly over Frame or Applet.

Two types of Executable programs in Javaare:-

1.)Java Applications(standalone)

2.)Java Applets(Distributed)

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Applets

To Load Applet:-

1.)Applets dont need a main method.

2.)Applets must be run under an applet viewer

or a Java compatible browser.3.)User I/O is not accomplished with Java's

Stream IO Classes.Instead,applets use the

interface provided by the AWT.

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Hierarchy of Applets and SwingObject

Component

Container

Frame Applet

Window

JAppletJFrame

Panel

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Applets

The HTML Applet Tags are:-1.)codebase

2.)code

3.)alt4.)name

5.)width, height

6.)align

7.)vspace, hspace

8.)

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Applet Display Methods1.)update()

2.)paint()

3.)setBackground()

4.)setForeground()

5.)getBackground()

6.)getForeground()

The default foreground color is black,

background color is light gray.

E t H dli d D l ti

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Event Handling and DelegationAn event is an unexpected external happening in the context of

hardware.Forexample when we press a key the electronic deviceinside the keyboard interrupt the system to send the keycode .

So that the system respond immediately by halting whatever it

was doing.

In this EventDrivenProgramming, the user control the

sequence of operations that the application executes.In eventdriven application the program will construct the various GUI

Components displayed those components and then enters into

a tightly loop weighting for user events to request an operation.

In java all the events are objects which describes the state

change in a source , the java.awt.event package defines a set of

event classes for the respective event type through this

package ,the objects of various event classes are constructed

when ever the user activates the respective GUI components.

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Event Handling and Delegation

The Programmer has to handle these generated events for

example when the user clicks on the button, the JVM constructs

an object of an action event class in which it stores all the details

like when and where the event is generated.

If we donot handle this generated event then the event issimply ignore .In GUI program the generated events are handled

with the concept of event delegation.

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EventDelegation:

The process of assigning an object to handle the events is calledevent delegation,the event handling objects are called listeners.

for example to inform a button component that it should

delegate action event to some listener, we call the add

actionListener method of button class by passing a reference of

the desired listener.

every component class in awt has addlistener method to

each event type that the component generates.

when a button with actionlistener is clicked then the

listener receives an action event object and executes its actionperformed method .there are two ways of delegating an event

to the listener

1)delegating an event to an external object

2)delegating to some object

h l d l h

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The Delegation Event Model has two parts:-

1.)Sources and Listeners.

Event Sources are:-

1.)Button

2.)Checkbox

3.)Choice4.)List

5.)Menu Item

6.)Scrollbar

7.)Text Components8.)Window

E t t d i t f A il bl

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Event types and interfaces Available

An Event is an object that describes a state change in a Source. A source is an

Object that generates an Event. A Listener is an object that is notified when anevent occurs.

java.awt.event package contains the following

classes for the respective event type.

1)ActionEvent

2)TextEvent3)ItemEvent

4)WindowEvent

5)KeyEvent

6)FocusEvent

7)AdjustmentEvent

8)MouseEvent9)Component Event

10)Container Event

11)Input Event

12)MouseWheelEvent

the following are the interfaces available

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the following are the interfaces available

in java.awt.event package to handle the respective event types

i.e

1)ActionListener2)TextListener

3)ItemListener

4)WindowListener

5)KeyListener

6)FocusListener

7)AdjustmentListener

8)MouseListener

9)MouseMotionListener

10)Component Listener11)Container Listener

12)MouseWheelListener

13)WindowFocusListener

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the following are the respective methods that are declared

in the respective interfaces

1)ActionListener----->(Buttons,TextField,TextArea,List)

public void actionPerformed(ActionEvent ae)

2)TextListener----->(TextFields,TextArea)

public void textChanged(TextEvent te)

3)ItemListener------>( Checkbox,CheckboxGroup)

public void itemStateChanged(ItemEvent ie)

4)WindowListener------>(Frames)

public void windowOpened(WindowEvent we)

public void windowClosed(WindowEvent we)public void windowClosing(WindowEvent we)

public void windowActivated(WindowEvent we)

public void windowDeactivated(WindowEvent we)

public void windowIconified(WindowEvent we)

public void windowDeiconified(WindowEvent we)

5)keyListener-------->(Buttons)public void KeyPressed(KeyEvent ke);

public void keyReleased(KeyEvent ke);

public void KeyTyped(KeyEvent ke);

6)FocusListener >(TextField TextArea Frames)

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6)FocusListener-------->(TextField,TextArea,Frames)

public void FocusGained(FocusEvent fe);

public void FocusLost(FocusEvent fe);

7)AdjustmentListener-------->(ScrollBar)

public void adjustmentValueChanged(AdjustmentEvent ae);8)MouseListener------------>

public void mousePressed(MouseEvent me);

public void mouseRelease(MouseEvent me);

public void mouseClicked(MouseEvent me);

public void mouseEntered(MouseEvent me);

public void mouseExited(MouseEvent me);9)MouseMotionListener--------->(ScrollBar)

public void mouseMoved(MouseEvent me);

public void mouseDragged(MouseEvent me);

10)ComponentListener--------->

public void componentResized(ComponentEvent ce);

public void componentMoved(ComponentEvent ce);public void componentShown(ComponentEvent ce);

public void componentHidden(ComponentEvent ce);

11)ContainerListener >

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11)ContainerListener--------->

public void containerAdded(ContainerEvent ce);

public void containerRemoved(ContainerEvent ce);

12)MouseWheelListener------------>public void mouseWheelMoved(MouseWheelEvent mwe);

13)WindowFocusListener------>

public void windowGainedFocus(WindowEvent we)

public void windowLostFocus(WindowEvent we)

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Layouts

1.)Flow Layout2.)Border Layout

3.)Card Layout

4.)Grid Layout5.)Grid Bag Layout

6.)Box Layout

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Layout Managers

A layout manager is a Java object associated with aparticular component.The layout manager controls

the components contained with in it.

Border Layout is the default Layout manager for a

Frame.

FlowLayout is the default layout manager for a

Panel.

1)Flow Layout

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1)Flow Layout:

This layout manager is the simplest layout manager

in the awt,as the name says it will layout all the GUIelements in a flowing.Which is similar to word processor

arranges words in a paragraph.

the setLayout method of the container class is usedto set the respective layout for the container.the

constructors of this flowlayout class are

1)FlowLayout() ---->default alignment is center

2) BorderLayout:

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2) BorderLayout:

This layout manager will divide the entire

space of the container into five zones i.eNorth,South,East,West,Center.

This Layout manager is the default layout

manager for the frame class,this border layout

sizes its individual component so that

automaticaly expand to fill the space available

for them.The add method of the container

class is use to add the individual componentsby specifiying the respective position such as

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f.add("North",b1); where

f-> Frame Objectb1->button Component

So that button b1 is added at the north

of the frame this BorderLayout can deal with

only five components i.e for component

located against four edges of the container,

and one located centrally an occupies theentire space of the center of the container.

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3)GridLayout:This enforces a gridbag layout for all the

components of a container.we specify the number of

gridrows and gridcolumns to the constructor of thisgridlayout class such as

f.setLayout(new GridLayout(2,2));

All the components will be added to the

container with respect to the specific grid dimensionso that the components are visible as matrix form, all

the individual components will be added to the

container with add methods such as

f.add(b1);f.add(b2); etc.......

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GridLayout :-

GridLayout(int rows,int cols);

GridLayout(int rows,int cols,int hs,int vs);

add(Component);

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Box layout :-public static Box createVerticalBox();

public static Box createHorizontalBox();

public static void createVerticalGlue();

public static void createHorizontalGlue();

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Card Layout

By using Card layout many screens orcomponents can be displayed but only

one at a time by selecting that particular

component.First(container),previous(container),

Next(container),last(container)

Swing

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SwingSwings are GUI(Graphical User Interface) based

Application. Look and feel is the concept of Swing

and the appearance of the Swing application is

same in different platforms.

AWT applications appearance is different indifferent platforms because Java depends on OS

level to overcome this problem Netscape and other

Scientists developed a set of classes called as

JFC(Java Foundation Classes)

java awt Graphics methods

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java.awt.Graphics methodsdrawLine(x1,y1,x2,y2);

drawRect(x,y,w,h)& fillRect(x,y,w,h)drawOval(x,y,w,h);&fillOval(x,y,w,h);

drawRoundRect(x,y,w,h,xarc,yarc);&

fillRoundRect(x,y,w,h,xarc,yarc);

draw3DRect(x,y,w,h,boolean raised);fill3DRect(x,y,w,h,boolean raised);

drawArc(x,y,w,h,stangle,total angle);

fillArc(x,y,w,h,stangle,total angle);

drawPolyline(x[],y[],int n);drawPolygon(x[],y[],int n);& fillPolygon(x[],y[],int n);

drawString(String,x,y);

setColor(Color);

j l

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java.awt.Component classpublic void setSize(w,h);

public void setBounds(x,y,w,h);

public void setVisible(boolean);

public setTitle(String);

public void setBackground(Color);

public void setForeground(Color);

public Color getBackground();

public Color getForeground();

public void setPreferredSize(Dimension);

public Dimension getPreferredSize();

public void setEnabled(boolean);

public int isEnabled();

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IconIcon is an interface implemented

in a class ImageIcon.

Icon i1=new ImageIcon("imagepath");

Ad l

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Adapter classesMouseAdapter

MouseMotionAdapter

ComponentAdapter

ContainerAdapter

KeyAdapterWindowAdapter

FocusAdapter

javax swing

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javax.swingBoth swing and awt packages are used to create the forms.AWT

follows Event delegation model.awt methods internally call the native methods . Native

methods which are written in other languages like c and c++.They

are system dependent and awt components are heavy weight

components . It requires more Memory ,Resources and more

processing time. Look & feel of awt components are different forHeterogeneous operating systems. look means appearance and

feel means interaction with user.

For the above reasons java soft people provided another api

that is JavaFoundationClasses(JFC). It is system independent. JFCis an extension to awt. So it is not replacement of awt. JFC

contains so many packages.

JFC contains :--->

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JFC contains : >

1) javax.swing:-->(x - means extension)To develop components like buttons ,

menus etc, to access windows like Jframe,

Jpanel etc2.)javax.event :- To access various events

like mouse,keyboard,etc..

3.)java.awt:- to access various layouts likeflow,grid,border etc..

F t f JFC

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Features of JFC

1) JFC components are light -weight components . They

use less System resourses.

2) JFC components have same look & feel on all

platforms

By using javax.swing.plaf package the programmer

can change the look & feel of components.

3) JFC offers a rich set of components with lot of

features.

4) JFC does not replace awt ,it is an extension.

javax.swing components follow the model-view-control

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javax.swing components follow the model view control

model --> represents state of the component.

view --> How the component is represented graphically

control-> Control view & model.

1) model stores the data that defines the state of the

button or text present in the text field.2) view creates visual representation of the component

from the data in the model.

3) control deals with the users interaction with the

components and modifies the model or the view inresponse to user action.

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JTabbedPane :-

JTabbedPane();JTabbedPane(int orientation);

JTabbedPane.TOP,BOTTOM,LEFT,RIGHT

SwingConstants. TOP,BOTTOM,LEFT,RIGHT

addTab(String label, Icon obj,

Component, String tooltiptext);

insertTab(String label, Icon obj,Component,String tooltiptext, int index);

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Annonymous Inner classes

new xxxxListener()obj.addxxxxListener(new xxxAdapter()

{

methods...});

Multi Threaded Programming

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Multi Threaded ProgrammingA Thread is a small process with in a program.

To create a thread either we have to extendthe Thread Class or implement the Runnable

Interface.

Methods in Thread class are:-1.)getName

2.)getPriority

3.)isAlive()4.)join

Multi Threaded Programming

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Multi Threaded ProgrammingMethods in Thread class are:-

5.)run

6.)sleep

7.)start

S t

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Syntax

java.lang.Thread class|

public static Thread currentThread();

public void setName(String);public String getName();

public static void sleep(long ms) throws

InterruptedException

S t

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Syntax

Thread();Thread(String tname);

Thread(Object obj,String tname);

public void start();

public void run();

public boolean isAlive();public void join() throws

InterruptedException

Syntax

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Syntax

>>>>> thread priorities :

Thread.MIN_PRIORITY 1

Thread.NORM_PRIORITY 5 (default)

Thread.MAX_PRIORITY 10

public void setPriority(int);

public int getPriority();

Threads

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Threads

A thread is a process or execution of a task,Performing only onetask is called a Single Thread . In multitasking there are 2 types.

1) Process based multitasking:- Executing more than oneprogram

-----------------------------------------

simultaneously is called Process based Multitasking.

2) Thread based Multitasking:-

-----------------------------------------

Executing the different parts of the same programsimultaneously is called Thread based Multitasking.

Round Robin

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Round Robin

Executing the first program after the secondprogram is called as Round Robin System.

Threads are useful in two ways:-

-------------------------------------------1) creation of animation and games.

2) Threads are used in an internet server to serve several

clients simultaneously.

Important Points1) A thread is a sequential flow of control with in a program Every

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1) A thread is a sequential flow of control with in a program . Every

program has at least one thread that is called the primaryThread.

2) Applications having only one thread is called single thread model.

3) The currentThread () method retrieves the reference of the

currentthread.

4) Multithreaded applications have more than one thread.

5) The Thread class is used to create and manipulate the threads in a

program.

6) You can use the Thread class or the runnable interface to

implement the threads.

Important Points

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Important Points7) A thread can have the following states.

a) New Thread : When an instance of Thread class is created,thethread enters into the newthread state.

b) Runnable : When the start() method is invoked,the thread

enters into the runnable state.

c) NotRunnable : The thread is said to be in not runnable state if

it is in

* Sleeping.

* Waiting.* Being blocked by another thread.

d) Dead : A thread can be either die naturally or killed. A natural

death when the loop in the run() method is complete.

Important Points

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p1) The start() method of the Thread class is used to start the thread.

2) The run() method contains the code which the thread executes.

3) A thread can be put to sleep using the sleep() method.

4) The threads are scheduled based on the priorities.

5) The synchronized keyword is used to ensure that no threads

access the same object simultaneously.

6) The methods wait(), notify(), notifyAll() are used for inter-threadcommunication.

7) Mutex : It is an object that is locked till a thread completes

execution.

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JDBC

JDBC

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JDBCJDBC stands for Java DataBase Connectivity

PROCEDURE FOR ESTABLISHING THE DATABASECONNECTION:-

1) Loading(Registering) the driver software into the

memory

2) Establishing the connection from the front endapplication to the server.(Database)

3) Creating the statements corresponding to the

connection generated.

4) Execute the created statements

5) Closing all the statements.

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Types of Drivers in JDBC are:-

1.)Jdbc-Odbc Bridge driver2.)Native API Partly Java Driver

3.)Jdbc-Net Pure Java Driver

4.)Native Protocol Pure Java Driver

Database connection

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1) java.lang.Class class

public static void forName("classname")

throws java.lang.ClassNotFoundException;

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

>>>> DriverManager class

public static Connection

getConnection("url",["uname"],"[pwd]")throws

SQLException

uniform resource locator :"jdbc:odbc:datasourcename"Connection

cn=DriverManager.getConnection("jdbc:odbc:oradsn1",

"scott","tiger");

Java.sql package

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q p g1.)Driver Manager

2.)Connection3.)Statement

4.)Resultset

5.)Resultsetmetadata6.)Databasemetadata

7.)Prepared Statement

8.)Callable Statement

Explanation

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ExplanationODBC API is a specification that is accessible to everyone as part of

this specification. Microsoft design the functions like sqlConnect ,sqldisconnect, sqlparse and sqlexecute. These functions can be used

by the programmer to deal with different databases.

So many companies has provided the implementation ofODBC

API.These implementations are known as ODBC drivers.On windows we can get the files with the extension .DLL (Dynamic

Link Library) which contains the implementation of functions.

JDBC is an open specification which can be implemented

by any one.The implementation of JDBC API is known as JDBC driver.

All most all the JDBC driver vendors supplies a set of classes as part

of JAR file

Explanation

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A Java programmer need not learn different set of APIs to write

the programs to deal with different databases.

As part of JDBC API specification java soft has specify differentinterfaces like

Java.sql.driver

Java.sql.conncection

Java.sql.statement

Java.sql.prepared Statement

Java.sql.blob

Java.sql.callable Statement

==================================

And a set of classes like DriverManager==================================

Java.sql.Date

Java.sql.Time

Java.sql.TimeStamp , Java.sql.Types

Explanation

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p a at oAny one can provide the implementation of above interfaces

ex :Oracle Corp has provided the implementation of thoseinterfaces to access oracle.

A java programmer needs to know the following information to

access a specific Database.

a) The name of class that provides the implementation of

java.sql.Driver interface.b)The format of jdbc URL

NOTE :we can obtain the information from the documents

provided by JDBC Driver vendor

Classes12.jar is a JDBC Driver provided by oracle

corporation as part of oracle

PARSING

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PARSINGThe DataBase Servers are responsible for PARSING the sql

statements submitted by the client.PARSING :

Breaking up the sql statement into multiple pieces(tokens) for

analyzing whether the statement follows the sql syntax or not. And

checking the availability of different database objects used in sql

statement.

PREPARED STATEMENT :-

Prepared Statement stmt = con.preparedStatement(insert into

tablename Values(?,?);Stmt.setInt(1,1);

Stmt.setInt(2,1);

Stmt.ExecuteUpdate();

PREPARED STATEMENTP d S dS (i i

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Prepared Statement stmt = con.preparedStatement(insert into

MyTab Values(?,?);

Stmt.SetInt(1,1);Stmt.SetInt(2,1);

Stmt.ExecuteUpdate();

PROCEDURE FOR USING PREPARED STATEMENT

1) prepared statement stmt =

con.preparedstatement(deleted from mytab where col1=?);

2.)Set the values of parameter using

Stmt.setInt(1,1); method

3)To execute the statement using executeUpdate(); or by using

executeQuery() method.Eg:- Prepared Statement stmt = con.preparedStatement(insert

into emp(empno,ename) values(?,?);

Stmt.SetInt(1,1);

Stmt.SetString(2,Sone); Stmt.executeUpdate();

Explanation

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Explanation

*) To get the information about a table we can use an interfaceResultSetMetaData

*) To execute the select statements we can use executeQuery(). It

is not recommeneded to use executeUpdate().

1) ExecuteQuery must be used for executing select

statements and the return value is a Resultset object which can beused to fetch the rows from the database.

2) ExecuteUpdate has to be used for the execution of non-select

statements and the return value is a integer.The return value

gives the number of rows affected or changed or modified.ex :A ResultSet r1= Stmt.executeQuery(Select * from emp);

A JDBC programmer can access only one row at a time from the

ResultSet when the ResultSet is created it will be pointing to

before first row.

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SERVLETS

Servlets

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Servlets are used to dynamically extend the

functionality of a web server. Every Servlet is a classin Java. Server side applets are called as Servelts.

They need to be deployed in a Web Server or

Application Server.

Servlets are small programs that

are designed to execute on the server side of a Web

Connection. They are platform independent.

Server side programming can be develped usingcomponents like Servlets and JSPs.

Servlets

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ServletsLife Cycle of a Servlet:-

1.)init()

2.)service()

3.)destroy().

Servlets need a Web server todeploy the Servlets. Apache Tomcat is used to

deploy the Server side components which is a

Web server to maintain Web Components of java.

Web applications must be created to represent

Servlets.

Servlets

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ServletsThe two important packages that are required to

build Servlets are:-

1.)javax.servlet

2.)javax.servlet.http.

The above two packages contains the classes and

interfaces that are required to develop Servlets in

Java.

javax.servlet package

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The javax.servlet package includes the following

interfaces:-Interfaces Description

1.)Servlet Declares life cycle methods for a Servlet.

2.)ServletConfig Allows Servlets to get initialization parameters

3.)ServletContext Enables Servlets to log events and accessinformation about their environment.

4.)ServletRequest Used to read data from a client request.

5.)ServletResponse Used to read data from a client response.

6.)SingleThreadModel Indicates that the Servlet is thread safe.

javax.servlet package

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j p gThe javax.servlet package includes the following

classes:-Classes Description

1.)GenericServlet Implements the Servlet and ServletConfig

interfaces.

2.)ServletInputStream Provides an Input Stream for readingrequests from a client.

3.)ServletOutputStream Provides an Output Stream for writing

responses to a client

4.)ServletException Indicates a Servlet error occurred.

5.)UnavailableException Indicates a Servlet is Unavailable.

javax.servlet.http package

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The javax.servlet.http package includes the

following interfaces:-Interfaces Description

1.)HttpServlet Request Enables Servlets to read data

from an Http request.

2.)HttpServletResponse Enables Servlets to write datato an Http response.

3.)HttpSession Allows session data to be read

and written.

4.)HttpSessionBindingListener Informs an object that it is

bound to or unbound from

a session.

javax.servlet.http package

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The javax.servlet.http package includes the

following classes:-Classes Description

1.)Cookie Allows state information to be

stored on a client machine.

2.)HttpServlet Provides methods to handle Httprequests and responses.

3.)HttpSessionEvent Encapsulates a session change

event.

4.)HttpSessionBindingEvent Indicates when a listener is

bound to or unbound from a

value, or that a session

attribute changed.

Servlets

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Servlets

1.)Session Tracking(i)Cookies

(ii)Http Session

(iii)URL Rewriting

(iv)Hidden form fields2.)Request Dispatcher

(i)include

(ii)forward

Java Server Pages(JSP)

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Client1 Client1W

E

B

SE

R

V

E

RClient2

JSPjspInit()

_jspService()

jspDestroy()

JSP(Java Server Pages)

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Life Cycle of JSP:-

1.)JSP is translated into a Servlet.2.)Translated Servlet is compiled.

3.)Loads into memory the compiled code.

4.)Creates object of the Servlet

5.)Executes jspInit()

6.) Executes _jspService()

7.)Finally executes the jspdDestroy()

Java Server Pages(JSP)1 )Scripting Elements of JSP are:

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1.)Scripting Elements of JSP are:-

a.)Scripletsb.)Declarations

c.)Expressions

2.)Directives

a.)Page Directiveb.)include Directive

c.)Taglib Directive

Java Server Pages(JSP)Default Objects in JSP:

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Default Objects in JSP:-

1.)HttpServletRequest Request

2.) HttpServletResponse Response

3.)Page Context PageContext

4.)HttpSession Session5.)ServletConfig Config

6.)ServletContext Context

7.)Object Page8.)Throwable Exception

9.)JSPwriter Out

Java Server Pages(JSP)

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JSP actions:-

1.)jsp:actionname2.)jsp:forward

3.)jsp:include

4.)jsp:useBean5.) jsp:setProperty

6.) jsp:getProperty

7.) jsp:plugin

8.)jsp:param

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Remote Method Invocation

Remote Method InvocationRMI is a Specification to enable one JVM to invoke

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RMI is a Specification to enable one JVM to invoke

methods in an object of other JVM.The two JVMs may be in the same system or in

different systems.

RMI server can be implemented as Middle tier

of 3-tier architecture, that enables us to invoke

distributed components among network systems.

RMI ClientRegisters

remote objects

in RMI registryDatabase

RMI Server(Middle Tier)

Searches for Remote Objects

Remote Method InvocationDi t ib t d C t f RMI

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Distributed Components of RMI:-

1.)RMI Server2.)RMI Client

1.)RMI Server:- RMI Server is an application to

register remote objects in RMI Registry.

RMI Registry is a service in Java to maintain

remote objects with unique name.

2.)RMI Client:-RMI Client is an application to searchremote objects in RMI Registry. If search found then

remote methods will be invoked.

Remote Method Invocation

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RMI Architecture:-

1.)Skeleton/Stub Layer2.)Remote Reference Layer

3.)Transport Layer

RMI Architecture:-

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RMI Client RMI Server

Client Application

Stub

Remote Reference

Layer

Transport Layer

Server Application

Skeleton

Remote Reference

Layer

Transport Layer

Look up

Explanation

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1.)The client request will be received by stub,

which is represented to the server application atclient side.

2.)Stub requests will be interpreted by Remote

Reference Layer3.)The request will be sent to the remote network

system through transport layer

4.)Client requests will be received by the Skeleton

at server side and executes the original method.

ServerSideProgramming

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(i)Creating Remote Interface:-

(a)Create one interface as sub interface of Remote there are nomethods in the Remote Interface.

(b)Declare all Remote methods(which will be invoked from any

network system) in the interface and each method must throw

Remote Exception.

(ii)Create Implementation Class:-(a)Create a class as subclass ofUnicastRemoteObject

implementation of Remote Interface .URO belongs to

java.rmi.server.*;(b)Invoke Superclass constructor from implementation class(URO

is superclass)

(c)Define all Remote Interface methods in the class.

ServerSideProgramming

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(iii)Create Server Application:-

(a) Create a class to register remote object in Rmi Registry.Naming Class:-to Register

Public static void rebind(url,remoteobject);

url-rmi:://hostname[:port]/bindname

Port-1099(default,optional)

To Compile:-

1.)javac *.java

2.)rmic implclass

3.)start rmiregistry

4.)java serverapplication

ClientSideProgramming

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g g(i) Create RMI Client application to search remote objects

and to invoke remote methods.

RMI Specifications1)C t O I t f

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1)Create One Interface

2)Give the Implementation for that interface.3)Binding

4)create client Application

Rules For Creating Interfacea) Our Interface must extends

java.rmi.RemoteInterface.

b) declare all the Business Logic methods .

c) All the Business logic methods Should throws

java.rmi.RemoteException

Rules While Implementing the Interface

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Rules While Implementing the Interface

a) our implementation class should extendsjava.rmi.server.UnicastRemoteObject

b) Should provide non-argument constructorwhich throws java.rmi.RemoteException

c) Should implements all the Business logic

methods declared in our remote interface

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Enterprise JavaBeans

ExplanationEJB components are server side components written entirely in the

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EJB components are server-side components written entirely in the

Java programming language

EJB components contain business logic only - no system-level

programming & services, such as transactions, security, life-cycle,

threading, persistence, etc. are automatically managed for the EJB

component by the EJB server.

EJB architecture is inherently transactional, distributed, portablemulti-tier, scalable and secure.

EJB components are fully portable across any EJB server and any OS.

EJB architecture is wire-protocol neutral--any protocol can be

utilized like IIOP, JRMP, HTTP, DCOM, etc.

Rapid application developmentBroad industry adoption

Application portability

Protection ofIT investment

EJBContainer:-

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It contains set of applications to interact with our service

object.Which provides a runtime environment for our EJBComponents in the form of frameWork.

Here FrameWork is nothing but libraries.The only difference

is Libraries are used with in our application where as in frame work

they are used our application.

so FrameWork has to Know our application specification.so comming to the EJB EjbContainer is the FrameWork and

application is nothing but EJBComponents.

-> In EJB we are provide with different Components Like

.Session Bean

.Entity Bean

.Message Driven Beans

RemoteInterface:-

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it contains all our Bussiness Logic Methods

which throwsjava.rmi.RemoteException;

it should extends javax.ejb.EJBObject

HomeInterface:-

it contains life cycle methods which should

throws

java.rmi.RemoteException,javax.ejb.CreateException;

it should extends javax.ejb.EJBHome

BeanClass:-

it Sh ld i l t f

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it Should implements one of our

EJBComponents that is(SessionBean,EntityBean) or

MessageDrivenBean)should not implement our

remote or home interface Should provide the

definition for all our Business Logic Methods

.Should give the corresponding definition for

the life cycle methods define in home interface.

Enterprise JavaBeans

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There are three kinds of Enterprise Beans:

(i)Session Beans,(ii)Entity Beans, and

(iii)Message-Driven Beans.

A message-driven bean combines features of a

session bean and a Java Message Service (JMS)

message listener, allowing a business component

to receive JMS. A message-driven bean enables

asynchronous clients to access

the business logic in the EJB tier.

Entity Bean is a Java class which implements an

Enterprise Bean interface and provides the

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p p

implementation of the business methods.

There are two types:

Container Managed Persistence (CMP) and

Bean-Managed Persistence (BMP).

Session Bean is used to represent a workflow on

behalf of a client.

There are two types:Stateless and

Stateful.

Stateless bean is the simplest bean. It doesn't

maintain any conversational state with

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maintain any conversational state with

clients between method invocations.

Stateful bean maintains state between

invocations.