I F 3 0 7 – P E M R O G R A M A N B E R O R I E N T A S I O B J E K ( J A V A )

N I K O I B R A H I M , M I T

E R I C K C O S T A N I O , S . K O M

F A K U L T A S T E K N O L O G I I N F O R M A S I

U N I V E R S I T A S K R I S T E N M A R A N A T H A

© 2 0 1 0

Kuliah 01Pengenalan PBO Berbasis Java

Class Attendance

Lectures schedule: Class A: Monday, 08.00 – 10.00

Class B: Monday, 10.30 – 13.00

Practical work schedule: Class A: Wednesday, 08.00 – 10.00

Class B: Wednesday, 10:00 – 12:00

All students must meet 75% of lecture‟s attendances to be eligible for the exams.

On Time

Students are expected to come on time for both lectures and practicals sessions.

More than 10 minutes means „no proof of attendace‟

Books & References

You may use any books you like most

However, for your guidelines: Object of Java (BlueJ Edition)

Core Java 2 Volume 1 Fundamental 8th Edition

Other References Java 6 API Documentation (Java Doc)

BlueJ Tutorials

BlueJ Reference Manual

Practical Works

There are several practical works

Checkpoint system (1-5 stage for each pracs)

Checkpoint 1 - basic concepts (everyone)

Checkpoint 2 - understand and describe (nearly everyone)

Checkpoint 3 - apply to new contexts (most)

Checkpoint 4 - compare, synthesize (only top 40%)

Checkpoint 5 - generalize, hypothesize, analyze (only top 20%)

Try your best, do not copy other‟s work

No late submission, no excuse

No cheating, no copying, no sharing

Work independently, ask for help

Softwares and Tools

JDK 1.6 + Java API Documentation

Editors: BlueJ (www.bluej.org): java editor + OOP concept

JGrasp (www.jgrasp.org): Java editor

NetBeans 6.9 (Java IDE)

Others:

Text Editor: Notepad, EditPlus, TextPad, UltraEdit, dll

Java Editor: JCreator, DrJava

IDE: Eclipse, IntelliJ IDEA

Silabus Perkuliahan

PertemuanPerkuliahan Praktikum

Materi Tanggal

Minggu 1 Perkuliahan ditiadakan 09 Agt -

Minggu 2 Pengenalan Pemrograman Berorientasi Objek (Java) 16 Agt P1 – Java Lang 1

Minggu 3Mengenal lebih dalam Java API dan Java Documentation

23 AgtP2 – Java Lang 2

Minggu 4Konsep Pemrograman Berorientasi Objek: Class, Object

30 AgtP3 – Java Sun Rise

Minggu 5 Method, Attributes, Encapsulation, & Overloading 06 Sep P4 – Smiley FaceMinggu 6 Libur Hari Raya Idul Fitri 13 Sep P5 – Java Clock

Minggu 7 Konsep Inheritance, Overriding, & Polymorphism 20 Sep P6 – Color Matcher

Minggu 8 Review Materi 27 Sep Ujian PraktikumUTS Ujian Teori 4-6 Okt -Minggu 9 Abstract Class dan Interface 18 Okt P7Minggu 10 OOP Advanced Features & Exception Handling 25 Okt P8Minggu 11 Java Collections Framework 01 Nov P9Minggu 12 Java Graphical User Interface (GUI) Bagian 1 08 Nov P10Minggu 13 Java Graphical User Interface (GUI) Bagian 2 15 Nov P11Minggu 14 Java Input/Output (Java IO) 22 Nov P12Minggu 15 Review Materi 29 Nov Ujian PraktikumUAS Ujian Teori 6-18 Des -

What Java?

1991: project “Oak” by James Gosling Berorientasi objek, berdasarkan bahasa C++

Dirancang untuk memprogram “home applicances” seperti TV sets, freezers, dll

Perlu berjalan di berbagai platform/processor dan harus murah

1994: HotJava (browser yang mampu menjalankan aplikasi java)

1995: implementasi publik yang pertama kali Semua browsers dapat menjalankan aplikasi java di web (java applet)

1998: The advent of Java 2: J2EE, J2ME, & J2SE

2002: Microsoft memperkenalkan bahasa baru yang memiliki sintaks yang mirip Java yaitu C# sebagai bagian dari platform .NET, sekaligusmenghilangkan Java dari Windows (harus install manual)

2006: Sun released parts of Java as Free/Open Source Software!

Versi saat ini: Java Development Kit (JDK) versi 1.6, biasa disebut JDK 6

In 2009, Sun Microsystem (the creator of Java) was acquired by Oracle (2nd

largest software company in the world)

Why Java?

cheap – almost all tools/softwares/components are available for free!

simple - partially modeled on C & C++ but greatly simplified and improved (eliminates pointers, simplifies multiple inheritance, etc.)

object-oriented programming language any conceptual component in your problem can be represented as an object in

your program

portable Java programs are compiled (translated) into the Java Virtual Machine (JVM)

code called bytecode

bytecode is machine-independent and run on any machine with a Java interpreter

the Java interpreter (part of JVM) further translates the bytecode into the machine language of the target machine

once compiled programs can run on any platform (with JVM installed) without being recompiled

Why Java? (cont.)

robust (reliable) - well developed exception handlingmechanisms, early checking for errors, etc.

secure - several built-in security mechanisms

multithreaded - can perform several tasks simultaneously

Where Java?

Desktop applications

Web applications Ebay, Amazon, AirAsia, klikBCA

Mobile Devices: mobile phone, smartphone, Blackberry, PDA

Smart Card: Simcard, Credit Card, RFID Card

(Contoh: E-Tol)

Enterprise Applications SAP, JD Edward, PeopleSoft, Oracle Business Suite

All machines & OS: windows, linux, mac, solaris

Java Platformhttp://download.oracle.com/javase/6/docs/

The following conceptual diagram illustrates all the component technologies in Java SE platform and how they fit together.

Typical Java Development Environment

Ada 5 tahapan pengembangan aplikasimenggunakan Java: Tahap 1: Creating a program Tahap 2: Compiling the program into bytecodes Tahap 3: Loading the program into memory Tahap 4: Byte verification Tahap 5: Execution

Tahap 1: Creating a program

Pada tahap ini, kita membutuhkan suatu editor untukmenulis kode program.

Kode program disimpan pada file berekstensi “.java”

Editor yang dapat digunakan:

Editor teks sederhana: notepad, editPlus, Textpad, UltraEdit

Editor teks berbasis Java: JGrasp, JCreator, DoctorJava

Editor teks + diagram sederhana: BlueJ

Integrated Development Environment (IDE):

Free: NetBeans, Eclipse, Oracle JDeveloper

Commercial: IntelliJ IDEA, IBM, BEA, Borland JBuilder

Tahap 2: Compiling

Pada tahap ini, kita compile kode program menjadi bytecodesdengan menggunakan perintah “javac”

Contoh: Kita membuat program dengan nama “Welcome.java” Perintah compile: javac Welcome.java

Apabila proses compile berhasil, maka compiler akan menghasilkan sebuahfile dengan ekstensi “.class” yaitu “Welcome.class”

File “.class” bukan bahasa mesin, melainkan merupakanBytecodes yang dapat dimengerti oleh Java Virtual Machine (JVM) JVM inilah yang akan mengeksekusi bytecodes ke dalam bahasa mesin JVM inilah yang menyebabkan Java begitu powerful, secure, scalable dan

multi-platform/portable Bytecode ini dapat dieksekusi di mesin/platform apapun asalkan telah

diinstal JVM yang dapat mengerti versi Java tempat bytecode tersebutdicompile sebelumnya

Untuk menjalankan JVM dan mengeksekusi program, kitagunakan perintah “java” Misalnya: java Welcome

Tahap 3-5

Phase 3: Loading a Program into Memory In Phase 3, the program must be placed in memory before it can

execute a process known as loading.

The class loader takes the .class files containing the program's bytecodes and transfers them to primary memory.

The class loader also loads any of the .class files provided by Java that our program uses.

Phase 4: Bytecode Verification In Phase 4, as the classes are loaded, the bytecode verifier

examines their bytecodes to ensure that they are valid and do not violate Java's security restrictions.

Phase 5: Execution In Phase 5, the JVM executes the program's bytecodes, thus

performing the actions specified by the program.

Latihan 1: HelloMe.java

Berdasarkan program “HelloWorld.java”, buatlahsebuah program baru bernama HelloMe.java

Pada saat di-run, program harus menampilkanpesan sbb:

Hello World, Niko!

Note: Ganti dengan nama Anda sendiri…

Biasakan beri NRP dan Nama anda (dalam bentukcomment)

Pertanyaan: apa perbedaan antara print danprintln ?

Pembahasan Program

0: // Exercise 1: HelloMe.java

1: // NIK: 730015, NAMA: Niko Ibrahim

2: public class HelloMe {

3: public static void main (String args[ ]) {

4: System.out.println("Hello World, Niko!");

5: }

6: }

Line 0: Komentar program, judul program, keterangan penting.

Line 1: Selalu tuliskan identitas penulis program.

Line 2: - Nama kelas. Setiap program Java minimal memiliki 1 deklarasi kelas.- Kelas diawali huruf kapital untuk setiap kata.- Untuk men-save public class ke file, harus diberi nama sesuai dengan

nama kelastsb dan diakhiri dengan ekstensi .java. Tentang public akan dibahas

nanti.

Line 3: main method the starting point of every Java application

Line 4: instruksi pada komputer untuk menulis suatu String (kata-kata)

Compile & Run menggunakan command window

Kita dapat menggunakan command window untuk melakukan compile dan run program Java.

Jalankan command window: Start menu run ketik cmd

Masuk ke direktori tempat Anda menyimpan file HelloMe.java

PERINTAH COMPILE : javac HelloMe.java

PERINTAH RUN : java HelloMe

Note: JAVA PATH harus di-set terlebih dahulu disistem operasi

print, println,dan printf

Untuk menuliskan sesuatu, Java memberikan 3 pilihan methods: print posisi akhir kursor berada di garis yang sama

Contoh: System.out.print ("Hello World");

println posisi akhir kursor berada di garis yang baru(seolah menekan enter)

Contoh: System.out.println("Hello World");

printf print dalam bentuk format tertentu (f = formatted)

Contoh: System.out.printf("%s\n %s\n", "Hello", "World");

Karakter Khusus

Kita juga dapat memasukan karakter khusus ke dalam String.

Untuk itu kita perlu menggunakan tanda “escape”, sbb: Contoh:

Sequence Character

\n New line\t Tab\r Return\” Quotation Mark\\ Backslash

String Result

"Code: JSPS\nPrice: $50.25" Code: JSPS

Price: $50.25"Niko\tIbrahim\r\Maranatha\tUniversity" Niko Ibrahim

Maranatha University"Type \"x\" to exit" Type "x" to exit

"C:\\java\\files" C:\java\files

Tipe Data Primitif

Java memiliki 8 tipe data primitifType Bits Bytes Minimum Range Maximum Range

byte 8 1 -128 or -27 127 or 27-1

short 16 2 -32,768 or -215 32,767 or 215-1

int 32 4 -2,147,483,648 or -231 2,147,483,647 or 231-1

long 64 8 -263 263-1

float 32 4 -3.4E38 3.4E38

double 64 8 -1.7E308 1.7E308

char 16 2 n/a n/a

boolean 8 1 n/a n/a

float 7 significant digits

double 16 significant digits

Variabel & Assignment

Java merupakan bahasa pemrograman yang bersifat static, artinya kita harus mendeklarasikan nama variabel sebelummeng-assign suatu nilai

Sintaks: tipeData namaVariabel

Contoh: int counter;

counter = 1;

Kita juga dapat secara langsung meng-assign suatu nilai kepadavariabel: int counter = 1;

boolean valid = false;

char letter = ‘A’;

char letter = 65;

double distance = 3.65e+9;

Untuk menginisialisai suatu konstanta, kita gunakan keyword “final”: final int DAYS_IN_NOVEMBER = 30;

final double SALEX_TAX = 0.75

String di Java

String dapat berisi huruf, angka, dan karakter khusus String bukan merupakan tipe data primitif melainkan

tipe data reference Untuk menyambung (concat) dua/lebih string, gunakan

operator +

Syntax:String variableName = value;

Examples:String message1 = "Invalid data entry";

String message2 = " ";

String message3 = null;

String firstName = "Niko";

String lastName = "Ibrahim";

String name = firstName + " " + lastName;

Operator Aritmatika

Program seringkali membutuhkan berbagai operasiaritmatika. Java menyediakan berbagai operasiaritmatika untuk melakukan:

Penjumlahan, Pengurangan,

Pembagian, Perkalian,

Sisa Pembagian

Parentheses ( )

Kita dapat menggunakan tanda kurung dalammelakukan operasi aritmatika.

Contoh: a dikalikan dengan hasil penjumlahanantara b dengan c

Yang manakah yang benar?1) a * b + c

2) a * (b + c)

3) (a * (b + c))

Note: operasi di dalam kurung akan diprosespertama kali!

Precedence dari operator aritmatika

Berikut ini adalah urutan pengerjaan operasi aritmatika(precedence)

Contoh urutan pengerjaan:

More: Operator Aritmatika

Operator Name # Operands Description

+ Addition 2 Add two operands

- Subtraction 2 Subtract the right operand from the left

* Multiplication 2 Multiplies the right operand and left operand

/ Division 2 Divides the right operand into the left operand

% Modulus 2 Returns the value that is left over after dividing the right operand into the left operand

++ Increment 1 Adds 1 to the operand (x = x + 1)

-- Decrement 1 Subtracts 1 from the operand (x = x -1)

+ Positive Sign 1 Promotes byte, short, and char types to the int type

- Negative Sign 1 Changes a positive value to negative, and vice versa

Secara keseluruhan Java memiliki 9 operator aritmatika:

Contoh-contoh operasi aritmatika

Integer Arithmetic:

int x = 14;

int y = 8;

Double Arithmetic:

double a = 8.5;

double b = 3.4;Operations Results Operations Results

int result1 = x + y;

int result2 = x – y;

int result3 = x * y;

int result4 = x / y;

int result5 = x % y;

int result6 = -y + x;

int result7 = --y;

int result8 = ++x;

result1 = 22

result2 = 6

result3 = 112

result4 = 1

result5 = 6

result6 = 6

result7 = 7

result8 = 15, x = 15

double result9 = a + b;

double result10 = a – b;

double result11 = a * b;

double result12 = a / b;

double result13 = a % b;

double result14 = -a + b;

double result15 = --a;

double result16 = ++b;

result9 = 11.9

result10 = 5.1

result11 = 28.90

result12 = 2.5

result13 = 1.7

result14 = -5.1

result15 = 7.5

result16 = 4.4Character Arithmetic:

char letter1 = ‘C’; // letter1 = ‘C’ Unicode integer is 67

char letter2 = ++letter1; // letter2 = ‘D’ Unicode integer is 68

Shorcut Assignment Operators

Java memiliki 6 shortcut assignment operators:Operator Name Description

= Assignment Assigns a new value to the variable

+= Addition Adds the operand to the starting variable value of the variable and assigns the result to the variable

-= Subtraction Subtracts the operand from the starting value of the variable and assigns the result to the variable

*= Multiplication Multiplies the operand by the starting value of the variable and assigns the result to the variable

/= Division Divides the operand by the starting value of the variable and assigns the result to the variable

%= Modulus Derives the value that is left over after dividing the right operand by the value in the variable, and then assigns this value to the variable

Contoh shortcut assignment operator

count += 1; // count is increased by 1

count -= 1; // count is decreased by 1

total += 100.0; // total is increased by 100.0

total -= 100.0; // total is decreased by 100.0

price *= .8; // price is multiplied by 0.8

sum += nextNumber;// sum is increased by the

value of nextNumber

Using Console for Input & Output

Mulai Java versi 5, cara paling mudah untuk mendapatkan input dariconsole adalah dengan menggunakan Scanner class

Untuk menampilkan output ke console adalah menggunakan method (fungsi) System.out.println

Sebelum menggunakan Scanner class, kita harus melakukan proses import sbb:

import java.util.Scanner;

Untuk membaca input dari console, kita buat objek scanner dengan caramenuliskannya sbb:

Scanner sc = new Scanner(System.in);

Ada 4 buah methods dari objek Scanner (yaitu sc) yang dapat kita gunakansesuai kebutuhan:

Method Description

next() or nextLine() Reads a String value from the user

nextInt() Reads an integer value from the user

nextDouble() Reads a double value from the user

nextBoolean() Reads a boolean value from the user

Latihan 2: Operasi Penambahan Integer// Addition program that displays the sum of two numbers.

import java.util.Scanner; // program uses class Scanner

public class Addition {

// main method begins execution of Java applicationpublic static void main( String args[] ){

// create Scanner to obtain input from command windowScanner input = new Scanner( System.in );

int number1; // first number to addint number2; // second number to addint sum; // sum of number1 and number2

System.out.print( "Enter first integer: " ); // prompt number1 = input.nextInt(); // read first number from user

System.out.print( "Enter second integer: " ); // prompt number2 = input.nextInt(); // read second number from user

sum = number1 + number2; // add numbers

System.out.print( "Sum is " + sum ); // display sum

} // end method main

} // end class Addition

Variabel dan Konsep Memori

Nama variable seperti number1, number2, dan sum sebenarnya berkorenpondensi dengan lokasi dimemori komputer.

Setiap variabel memiliki nama, tipe, ukuran, dan nilai

Kode dari contoh 2:

number1 = input.nextInt(); // read first number from user

Pada saat kode tsb dieksekusi, nomor yang diketik oleh user akandisimpan ke suatu lokasi dimemori yang telah diberikan kepadanumber1 oleh compiler.

Misal, user memasukkan angka 45, maka komputer akanmenyimpan nilai integer ke lokasi number1 sbb:

Variabel dan Konsep Memori (cont.)

number2 = input.nextInt(); // read second number from user

Memory locations after storing values for number1 and number2.

sum = number1 + number2; // add numbers

Memory locations after calculating and storing the sum of number1 and number2.

Latihan 3: InvoiceApp.java// Latihan 3: InvoiceApp.java

import java.util.Scanner;

public class InvoiceApp {

public static void main (String args[]) {

// create a Scanner object

Scanner sc = new Scanner(System.in);

// read a string

System.out.print("Enter product code: ");

String productCode = sc.next();

// read a double value

System.out.print("Enter price: ");

double price = sc.nextDouble();

// read an int value

System.out.print("Enter quantity: ");

int quantity = sc.nextInt();

// perform a calculation and display the result

double total = price * quantity;

System.out.println();

System.out.println(quantity + " " + productCode + " @ "

+ price + " = " + total);

}

}

Ekspresi Boolean

Ekpresi Boolean biasanya digunakan untuk mengatur control statements.

Ekpresi Boolean menghasilkan nilai true atau false. Ada 6 operator relational yang membandingkan operand

bertipe data primitif dan menghasilkan nilai boolean. Dalam suatu ekpresi boolean, suatu operand dapat berupa

literal, ekpresi aritmatika, maupun keyword true atau false.

Operator Name Description

== Equality Returns a true value if both operands are equals

!= Inequality Returns a true value if the left and right operands are not equal

> Greater Than Returns a true value if the left operand is greater than the rightoperand

< Less Than Return a true value if the left operand is less than the rightoperand

>= Greater Than Or Equal Returns a true value if the left operand is greater than or equalto the right operand

<= Less Than or Equal Return a true value if the left operand is less than or equal tothe right operand

Contoh ekpresi boolean

discountPercent == 2.3 // equal to a numeric literal

letter == ‘y’ // equal to a char literal

isValid == false // equal to the false value

subtotal != 0 // not equal to a numeric literal

years > 0 // greater than a numeric literal

i < months // less than a variable

subtotal >= 500 // greater than or equal

to a numeric literal

quantity <= reorderPoint // less than or equal to a variable

Kita juga dapat menggabungkan beberapa nilai Boolean dengan menggunakan operator AND dan OR:

Operator Name Example Description

&& AND a && b true if both a and b are true|| OR a || b true if either a or b (or both) is true^ XOR a ^ b true if only a or b is true! NOT !a true if a is not true

String Comparison

Karena String adalah suatu objek, bukan tipe data primitif, kita tidak dapat menggunakan operator relational untukmembandingkannya.

Kita harus menggunakan method “equals” atau“equalgnoreCase” yang dimiliki oleh kelas String.

Contoh: firstName.equals("Niko"); // equal to a string literal

firstName.equalsIgnoreCase("Niko"); // equal to a string literal

firstName.equals(""); // equal to an empty string

!lastName.equals("Ibrahim"); // not equal to a string literal

!code.equalsIgnoreCase(productCode); // not equal to another

string variable

firstName == null // equal to a null value

firstName != null // not equal to a null value

Java 6 only: firstName.isEmpty() // check if firstName is an

empty string

Next Week!

Struktur Control: Looping

For Loop

For Each Loop

While Loop

Do While Loop

Branching

If Else

Switch Case

Konsep Arrays

Java Documentation