The aim of this tutorial is to create an application with the Enterprise Application Framework – JVx. Moreover, a quick overview of the framework's possibilities will be given.

The application's task is to display the data from a database table and make them editable. The application requests authentification with user name and password.

The following skills and tools are needed:

• JVx Binary package
• Eclipse IDE (>= 3.4) with JDT (Recommended: Eclipse IDE for Java EE developers)
• JDK 5.0 (1.5) or higher
• HyperSQL library (http://www.hsqldb.org)
• Database and SQL skills

This documentation covers the following areas

• JVx folder structure
• Eclipse project configuration
• Application development
  • Client
  • Server
• Creation of a work screen
• Use of a HyperSQL database

Folder structure

To develop an application with JVx, a special folder structure is recommended. This simplifies the Build process and separates any dependencies between Client and Server. This structure is to be created as follows:



A conventional structure:

can also be used on request. However, the documentation refers to the recommended structure.

Once the folder structure has been created, copy the library jvxclient.jar to the folder libs/client and the library jvx.jar to the folder libs/server. Both libraries are contained in the JVx binary package.

Project configuration

Once the configuration steps have been performed, a new project can be created with Eclipse:

• File / New / Java Project
• Note that the project has to be set up in the application folder firstapp.
  
• Remove the src folder from the Source Folders
  Set the folders src.client, src.server and test as Source Folder
  
• Add the jvx.jar library, from the project directory JVxFirstApp/libs/server
  
• The project can now be created

The project is shown in Eclipse as follows:

The src folder can be deleted for consistency, as it is not needed in our application.

Application development

On the server side, the application needs a configuration file for the settings that only concern the application. For the configuration of the server, an extra configuration file is needed. First we create the file for the application:

• File / New / File - config.xml
  (created directly in the application folder JVxFirstApp)
  

The file is filled as follows:

<?xml version="1.0" encoding="UTF-8"?>

<application>
  <securitymanager>
    <class>com.sibvisions.rad.server.security.XmlSecurityManager</class>
    <userfile>users.xml</userfile>
  </securitymanager>

  <!-- predefined life-cycle object names -->
  <lifecycle>
    <mastersession>apps.firstapp.Session</mastersession>
    <application>apps.firstapp.Application</application>
  </lifecycle>  

</application>

The server configuration file must be stored in the folder ../JVxFirstApp/rad/server.

However, the folder does not appear in our Eclipse project because it is at a higher folder level. The configuration file could be created directly in the file system or we can create a folder link in our project:

• File / New / Folder
  

The configuration file can then be created:

• File / New / File - config.xml
  

The file is filled as follows:

<?xml version="1.0" encoding="UTF-8"?>

<server>
</server>

The server does not need any special parameters for our application.

For the client, we now need a class of type javax.rad.application.IApplication. A standard implementation of JVx is implemented via com.sibvisions.rad.application.Application. We then derive our client from it and thereby create a class, in the directory src.client, with the following source code:

package apps.firstapp;

import javax.rad.application.genui.UILauncher;
import javax.rad.remote.IConnection;

import com.sibvisions.rad.application.Application;
import com.sibvisions.rad.server.DirectServerConnection;

/**
 * First application with JVx, Enterprise Application Framework.
 * <p/>
 * @author René Jahn
 */
public class FirstApplication extends Application
{
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Initialization
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /**
   * Creates a new instance of <code>FirstApplication</code> with a technology
   * dependent launcher.
   * <p/>
   * @param pLauncher the technology dependent launcher
   */
  public FirstApplication(UILauncher pLauncher)
  {
    super(pLauncher);
  }
  
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Overwritten methods
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /**
   * {@inheritDoc}
   */
  @Override
  protected IConnection createConnection() throws Exception
  {
    return new DirectServerConnection();
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected String getApplicationName()
  {
    return "firstapp";
  }

}  // FirstApplication

It is now time for the first start of the application. To do so, we set up a Runtime configuration:

• Run / Run Configurations... / Application - New launch configuration - with the settings:
  
  

The application can now be started and looks as follows:

The first login attempt fails with the following message

Userfile 'users.xml' does not exist!

This file was defined in the  config.xml file of the application; however, it has not yet been created. We do so now here:

• File / New / File - users.xml
  

We fill the file with the following:

<?xml version="1.0" encoding="UTF-8"?>

<users>
  <user name="admin" password="admin"/>
</users>

Any number of user lines can be entered!

Now the login to the application works perfectly. However, to fulfill our task, we still need the possibility to display or edit a database table. We will now turn to this part of the task.

Create a work screen

Before we create a WorkScreen, we prepare the application to display the WorkScreen. To do so, we extend our FirstApplication class as follows:

package apps.firstapp;

import javax.rad.application.genui.UILauncher;
import javax.rad.genui.UIImage;
import javax.rad.genui.component.UIButton;
import javax.rad.genui.container.UIToolBar;
import javax.rad.genui.menu.UIMenu;
import javax.rad.genui.menu.UIMenuItem;
import javax.rad.remote.IConnection;

import com.sibvisions.rad.application.Application;
import com.sibvisions.rad.server.DirectServerConnection;

/**
 * First application with JVx, Enterprise Application Framework.
 * <p/>
 * @author René Jahn
 */
public class FirstApplication extends Application
{
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Initialization
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /**
   * Creates a new instance of <code>FirstApplication</code> with a technology
   * dependent launcher.
   * <p/>
   * @param pLauncher the technology dependent launcher
   */
  public FirstApplication(UILauncher pLauncher)
  {
    super(pLauncher);
  }
  
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Overwritten methods
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /**
   * {@inheritDoc}
   */
  @Override
  protected IConnection createConnection() throws Exception
  {
    return new DirectServerConnection();
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected String getApplicationName()
  {
    return "firstapp";
  }
  
  /**
  * {@inheritDoc}
  */
  @Override
  protected void afterLogin()
  {
    super.afterLogin();
  
    //configure MenuBar
  
    UIMenu menuMasterData = new UIMenu();
    menuMasterData.setText("Master data");
  
    UIMenuItem miDBEdit = createMenuItem
                          ("doOpenDBEdit", null, "DB Edit", 
                           UIImage.getImage(UIImage.SEARCH_LARGE));

    menuMasterData.add(miDBEdit);

    //insert before Help
    getMenuBar().add(menuMasterData, 1);
  
    //configure ToolBar

    UIToolBar tbMasterData = new UIToolBar();
  
    UIButton butDBEdit = createToolBarButton
                         ("doOpenDBEdit", null, "DB Edit", 
                          UIImage.getImage(UIImage.SEARCH_LARGE));
  
    tbMasterData.add(butDBEdit);
  
    getLauncher().addToolBar(tbMasterData);
  }

  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Actions
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  /**
   * Opens the edit screen.
   */
  public void doOpenDBEdit()
  {
    //TODO open the workscreen
  }

}  // FirstApplication

We now create the client class for our work screen:

• File / New / Class
  

and use the following Source Code

package apps.firstapp.frames;

import javax.rad.genui.container.UIGroupPanel;
import javax.rad.genui.container.UIInternalFrame;
import javax.rad.genui.control.UITable;
import javax.rad.genui.layout.UIBorderLayout;
import javax.rad.remote.AbstractConnection;
import javax.rad.remote.MasterConnection;

import com.sibvisions.rad.application.Application;
import com.sibvisions.rad.model.remote.RemoteDataBook;
import com.sibvisions.rad.model.remote.RemoteDataSource;

/**
 * A simple database table editor.
 * <p/>
 * @author René Jahn
 */
public class DBEditFrame extends UIInternalFrame
{
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Class members
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /** the application. */
  private Application application;
  
  /** the communication connection to the server. */
  private AbstractConnection connection;
  
  /** the DataSource for fetching table data. */
  private RemoteDataSource dataSource = new RemoteDataSource();
  
  /** the contacts tabl. */
  private RemoteDataBook rdbContacts = new RemoteDataBook();
  
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // Initialization
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  /**
   * Creates a new instance of DBEditFrame for a specific application.
 * <p/>
 * @param pApp the application
 * @throws Throwable if the remote access fails
 */
 public DBEditFrame(Application pApp) throws Throwable
 {
 super(pApp.getDesktopPane());
 
 application = pApp;
 
 initializeModel();
 initializeUI();
 }
 
 /**
 * Initializes the model.
 * <p/>
 * @throws Throwable if the initialization throws an error
 */
 private void initializeModel() throws Throwable
 {
 //we use a new "session" for the screen
 connection = ((MasterConnection)application.getConnection()).
 createSubConnection("apps.firstapp.frames.DBEdit");
 connection.open();

 //data connection
 dataSource.setConnection(connection);
 dataSource.open();
 
 //table
 rdbContacts.setDataSource(dataSource);
 rdbContacts.setName("contacts");
 rdbContacts.open();
 }
 
 /**
 * Initializes the UI.
 * <p/>
 * @throws Exception if the initialization throws an error
 */
 private void initializeUI() throws Exception
 {
 UIGroupPanel group = new UIGroupPanel();
 group.setText("Available Contacts");
 
 UITable table = new UITable();
 table.setDataBook(rdbContacts);
 
 group.setLayout(new UIBorderLayout());
 group.add(table);
 
 //same behaviour as centered component in BorderLayout 
 setLayout(new UIBorderLayout());
 add(group); 

 setTitle("Contacts");
 setSize(new UIDimension(400, 500));
 } 

 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // Overwritten methods
 //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 /**
 * Closes the communication connection and disposes the frame.
 */
 @Override
 public void dispose()
 {
 try
 {
 connection.close();
 }
 catch (Throwable th)
 {
 //nothing to be done
 }
 finally
 {
 super.dispose();
 }
 }

} // DBEditFrame

The WorkScreen is now ready and can be integrated in the application. We now implement the missing call:

public class FirstApplication extends Application
{
  ...
  ...
  ...

  /**
   * Opens the edit screen.
   * <p/>
   * @throws Throwable if the edit frame can not be opened
   */
  public void doOpenDBEdit() throws Throwable
  {
    DBEditFrame frame = new DBEditFrame(this);
 
    configureFrame(frame);
 
    frame.setVisible(true);
  }

}  // FirstApplication

The client implementation is now finished. Before we can use the application, we must create the missing server classes. We create the following classes:

package apps.firstapp;

import com.sibvisions.rad.server.GenericBean;

/**
 * The LCO for the application.
 * <p/>
 * @author René Jahn
 */
public class Application extends GenericBean
{

}  // Application

package apps.firstapp;

import com.sibvisions.rad.persist.jdbc.DBAccess;
import com.sibvisions.rad.persist.jdbc.IDBAccess

/**
 * The LCO for the session.
 * <p/>
 * @author René Jahn
 */
public class Session extends Application
{
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // User-defined methods
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  
  /**
   * Returns access to the database.
   * 
   * @return the database access
   * @throws Exception if a connection error occurs
   */
  public IDBAccess getDBAccess() throws Exception
  {
    DBAccess dba = (DBAccess)get("dBAccess");
  
    if (dba == null)
    {
      dba = new HSQLDBAccess();
   
      dba.setUrl("jdbc:hsqldb:hsql://localhost/firstappdb"); 
      dba.setUsername("sa");
      dba.setPassword("");
      dba.open();
     
      put("dBAccess", dba);
    }
  
    return dba;
  }  

}  // Session

package apps.firstapp.frames;

import javax.rad.persist.IStorage;

import com.sibvisions.rad.persist.jdbc.DBStorage;

import apps.firstapp.Session;

/**
 * The LCO for the DBEdit WorkScreen.
 * <p/>
 * @author René Jahn
 */
public class DBEdit extends Session
{
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // User-defined methods
  //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

  /**
   * Returns the contacts storage.
   * 
   * @return the contacts storage
   * @throws Exception if the initialization throws an error
   */
  public IStorage getContacts() throws Exception
  {
    DBStorage dbsContacts = (DBStorage)get("contacts");
  
    if (dbsContacts == null)
    {
      dbsContacts = new DBStorage();
      dbsContacts.setDBAccess(getDBAccess());
      dbsContacts.setFromClause("CONTACTS");
      dbsContacts.setWritebackTable("CONTACTS");
      dbsContacts.open();
   
      put("contacts", dbsContacts);
    }
  
    return dbsContacts;
  }
  
}  // DBEdit

The application is now fully implemented and ready to run. So as to be able to work with the application, we need a database with the CONTACTS table which we want to access. The configuration of HyperSQL DB is not described in detail in this document, as the examples on the project page are detailed and suffice. In the next chapter, you will find a short summary of the necessary steps.

Create database

The following steps should take place to create and start a HyperSQL DB.

• Copy the HyperSQL JDBC-Driver (hsqldb.jar) to the directory
  ../JVxFirstApp/libs/server/
• Add the JDBC-Driver to the CLASSPATH of the JVxFirstApp Project
• Create a database with the alias firstappdb and the following table:

  create table CONTACTS
  (
    ID            INTEGER IDENTITY,
    FIRSTNAME     VARCHAR(200) not null,
    LASTNAME      VARCHAR(200) not null,
    BIRTHDAY      DATE,
    STREET        VARCHAR(200),
    NR            VARCHAR(200),
    ZIP           VARCHAR(4),
    TOWN          VARCHAR(200)
  )

• Start the database, e.g.:

  java -cp ../libs/server/hsqldb.jar org.hsqldb.Server 
  -database.0 file:firstappdb -dbname.0 firstappdb

The first application

Once the database has been started, the application can also be started. The final application should look as follows:

The Source Code and the Eclipse project can be found in the Download section.