Just Lunch For Java Source

Contoh Mudah DB4O untuk JAVA

2010-06-26T13:40:00.005+07:00

Seperti yang saya katakan pada posting sebelumnya, maka kali ini saya akan membahas tentang contoh mudah DB4o untuk java. Saya berasumsi bahwa anda menggunakan Netbeans dan telah menginstal DB4O library kedalam netbeans. Untuk anda yang belum menggunakan Netbeans silahkan menunggu posting saya selanjutnya, dimana saya akan membahas cara menginstall Netbeans dan DB4O library.

Pada contoh ini saya menggunakan Mahasiswa sebagai entity class nya. Berikut adalah gambar kelas Mahasiswa :

Selanjutnya adalah membuat kode program dari entity class diatas. Berikut adalah kode programnya :

package DB4o.db4o1.PDModel;

/**

* @author aji

public class Mahasiswa {

String namaMahasiswa;

String nomorMahasiswa;

int jmlMKuliahDiambil;

public Mahasiswa(String namaMahasiswa, String nomorMahasiswa, int jmlMKuliahDiambil) {

this.namaMahasiswa = namaMahasiswa;

this.nomorMahasiswa = nomorMahasiswa;

this.jmlMKuliahDiambil = jmlMKuliahDiambil;

}

public int getJmlMKuliahDiambil() {

return jmlMKuliahDiambil;

}

public String getNamaMahasiswa() {

return namaMahasiswa;

}

public String getNomorMahasiswa() {

return nomorMahasiswa;

}

public void setJmlMKuliahDiambil(int jmlMKuliahDiambil) {

this.jmlMKuliahDiambil = jmlMKuliahDiambil;

}

public void setNamaMahasiswa(String namaMahasiswa) {

this.namaMahasiswa = namaMahasiswa;

}

public void setNomorMahasiswa(String nomorMahasiswa) {

this.nomorMahasiswa = nomorMahasiswa;

}

@Override

public String toString() {

return namaMahasiswa+"/"+nomorMahasiswa+"/"+jmlMKuliahDiambil;

}

Selanjutnya adalah membuat main programnya. Berikut adalah kode programnya :

package DB4o.db4o1;

import DB4o.db4o1.PDModel.Mahasiswa;

import com.db4o.Db4o;

import com.db4o.ObjectContainer;

import com.db4o.ObjectSet;

/**

* @author aji

public class Main {

public Main() {

ObjectContainer db = Db4o.openFile("Mahasiswa.ODB");

try {

//persistance

Mahasiswa mh = new Mahasiswa("Riki", "12302123456", 11);

db.set(mh);

System.out.println(mh +" sudah disimpan");

Mahasiswa mh2 = new Mahasiswa("Bento", "12302123457", 10);

db.set(mh2);

System.out.println(mh2 +" sudah disimpan");

//list hasil objek mh

ObjectSet hasil = db.get(mh);

listResult(hasil);

}finally{

db.close();

}

/**

* method untuk menampilkan hasil

public static void listResult(ObjectSet res){

System.out.println(res.size());

while (res.hasNext()) {

System.out.println(res.next());

}

/**

* main method

public static void main(String[] args){

Main Test = new Main();

}

Contoh diatas merupakan contoh mudah DB4O untuk java dalam hal client/single user mode. Pada contoh diatas dapat dilihat telah dibuat file "Mahasiswa.ODB" dan dipanggil oleh ObjectContainer. Selanjutnya membuat objek "mh" dari entity class Mahasiswa. Objek mh kemudian disimpan ke dalam database dengan perintah set(). Hal yang sama terjadi pada objek ke 2 (mh2). Kemudian program akan menampilkan data "mh" dengan menggunakan method "listResult" dengan sebuah parameter bertipe ObjectSet. Berikut adalah gambar output dari program diatas :

Demikian contoh sederhana penggunaan DB4O untuk java.Anda juga dapat mengunduh seluruh kode program(lihat halaman download bagian Sourcecode). Semoga dapat berguna untuk anda.

Db4o Sebagai Database Berorientasi Objek(Object Oriented Database atau OODB)

2010-06-23T17:07:00.003+07:00

Wooke....hihihi...kali ini saya ingin menceritakan tentang DB4O. Seperti yang kita ketahui sekarang Pemrograman Berorientasi Objek(Object Oriented Programming atau OOP) sudah sangat populer dan berkembang dengan pesat. Nah...selain OOP ternyata teknologi database pun ikut berkembang. Berkembangnya teknologi database mulai dari model hierarchial, network, dan kemudian ke model relational jika dikaitkan dengan teknologi OOP maka dapat dikatakan teknologi database pun berkembang menjadi model Database Berorientasi Objek(Object Oriented Database atau OODB).

Pada perkembangannya terdapat berbagai produk software OODB, yaitu: ObjectDB, DB4O, ObjectStore dan lainnya. Namun saya hanya membahas tentang DB4O, khususnya DB4O untuk JAVA.

DB4o dapat berjalan di dua platform, yaitu JAVA dan dotNet. DB4o sangat unik karna dapat di-embed kedalam equipment atau device, seperti : server platform, desktop, bahkan mobile. Hal ini dikarenakan DB4O memiliki Footprint yang cukup kecil. Meskipun demikian class library DB4O menyediakan berbagai fitur yang lengkap sehingga menjadi sangat cocok untuk di-embed kedalam aplikasi.

Jadi...apakah anda tertarik menggunakan OODB?sudah pasti anda harus mengerti konsep OOP terlebih dahulu....hihihihi... ^_*...next time saya akan membahas contoh mudah penggunaan DB4O untuk JAVA. Anda juga bisa mendownload DB4O disini atau kunjungi langsung situs resminya www.db4o.com.

Semoga dapat bermanfaat untuk anda.

sumber :

http://www.db4o.com/about/productinformation

http://www.db4o.com/about/productinformation/whitepapers/

Welcome Back!!!

2010-06-22T17:23:00.001+07:00

Yeah...welcome back to me!!! ^_^

after all this time never post on this blog....wooot?since 2007...nvm

for the next post ill use indonesian language....but i've put the Google Translation tool.. ^_*

cyah...

Simple example for object-oriented programming

2007-07-07T10:21:00.004+07:00

An example that better demonstrates object-oriented programming:

// OddEven.java
 import javax.swing.JOptionPane;
 public class OddEven {
 private int input;
 public OddEven() { 
 input = Integer.parseInt(JOptionPane.showInputDialog ...
 ("Please Enter A Number"));
 }

 public void calculate() {
 if (input % 2 == 0)
 {JOptionPane.showInputDialog("Even"); }
  else      
 {JOptionPane.showInputDialog("Odd"); }
 }
 public static void main(String[] args) {
 OddEven number = new OddEven();
 number.calculate();
 }
 }

The import statement imports the JOptionPane class from the javax.swing package.
The OddEven class declares a single private field of type int named input. Every instance of the OddEven class has its own copy of the input field. The private declaration means that no other class can access (read or write) the input field.
OddEven() is a public constructor. Constructors have the same name as the enclosing class they are declared in, and unlike a method, have no return type. A constructor is used to initialize an object that is a newly created instance of the class. In this case, the constructor initializes the input field to the value entered into a JOptionPane input dialog. The dialog returns a String which is converted to an int by the Integer.parseInt(String) method.
The calculate() method is declared without the static keyword. This means that the method is invoked using a specific instance of the OddEven class. (The reference used to invoke the method is passed as an undeclared parameter of type OddEven named this.) The method tests the expression input % 2 == 0 using the if keyword to see if the remainder of dividing the input field belonging to the instance of the class by two is zero. If this expression is true, then it prints Even; if this expression is false it prints Odd. (The input field can be equivalently accessed as this.input, which explicitly uses the undeclared this parameter.)
OddEven number = new OddEven(); declares a local object reference variable in the main method named number. This variable can hold a reference to an object of type OddEven. The declaration initializes number by instantiating an instance of the OddEven class using the new keyword and then calling the OddEven() constructor to initialize the newly created object.
The statement number.calculate(); calls the calculate method. The instance of OddEven object referenced by the number local variable is used to invoke the method and passed as the undeclared this parameter to the calculate method.
For simplicity, error handling has been ignored in this example. Entering a value that is not a number will cause the program to crash. This can be avoided by catching and handling the NumberFormatException thrown by Integer.parseInt(String).
Result

Java Example

2007-07-07T10:14:00.005+07:00

Hallo World
This is a minimal usage of Java, but it does not demonstrate object-oriented programming well. No object is explicitly created since the keyword new> is never used.

// Hello.java
public class Hello {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}

To execute this program, one first saves the above code as a file named Hello.java. One then compiles it to bytecode:

$ javac Hello.java

which produces a file named Hello.class . This class is then launched with the java launcher (usually named java, java.exe, or some variant depending on the operating system).

$ java Hello
Hello, World!

$

About Java Programming

2007-07-07T10:01:00.002+07:00

Java is a programming language originally developed by Sun Microsystems and released in 1995. Java applications are typically compiled to bytecode, although compilation to native machine code is also possible. At runtime, bytecode is usually either interpreted or compiled to native code for execution, although direct hardware execution of bytecode by a Java processor is also possible.
The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. JavaScript, a scripting language, shares a similar name and has similar syntax, but is not directly related to Java.

The original Java compilers, virtual machines, and class libraries were developed by Sun Microsystems from 1995. Others have also developed alternative implementations of these Sun technologies, the most well known of which are the free software Java implementations>, such as the
GNU Compiler for Java and GNU Classpath.
Between November 2006 and May 2007, Sun Microsystems made available most of their Java technologies under the
GNU General Public License, in compliance with the specifications of the Java Community Process, thus making almost all of Sun's Java also free software.

Java Releases

The Java project has seen many release versions. Since 1997 they are:

J2SE 1.1.4 (Sparkler) September 12, 1997
- JDK 1.1.5 (Pumpkin) December 3, 1997
- JDK 1.1.6 (Abigail) April 24, 1998
- JDK 1.1.7 (Brutus) September 28, 1998
- JDK 1.1.8 (Chelsea) April 8, 1999
J2SE 1.2 (Playground)
December 4, 1998
- J2SE 1.2.1 (none)
  March 30, 1999
- J2SE 1.2.2 (Cricket) July 8, 1999
J2SE 1.3 (Kestrel) May 8, 2000
- J2SE 1.3.1 (Ladybird) May 17, 2001
J2SE 1.4.0 (Merlin)
February 13, 2002
- J2SE 1.4.1 (Hopper) September 16, 2002
- J2SE 1.4.2 (Mantis) June 26, 2003
J2SE 5.0 (1.5.0) (Tiger) September 29, 2004
Java SE 6 (1.6.0) (Mustang) December 11, 2006