JavaFx 2.2 – Webservice - Oracle DB example

This short example demonstrates us, how javafx works as a client, in an application having a client-server arhitecture. The tutorial uses the following softwares and tools, and if you wish to try it, you should have installed, these on your computer:

-         Oracle Database Express Edition 11g Release

(http://www.oracle.com/technetwork/products/express-edition/downloads/index.html)

-         Java SE Development Kit 7

JavaFX SDK is now included in the JDK 7 for Windows, Mac OS X, and Linux x86/x64.

(http://www.oracle.com/technetwork/java/javase/downloads/jdk7u7-downloads-1836413.html)

-         Netbeans 7.2 Development IDE

(http://netbeans.org/downloads/index.html). Download the Java EE or the full version of Netbeans. This setup will install to your computer the Apache Tomcat and also the Glassfish Server if you check these options. In this tutorial we use just the Tomcat Apache Server 7.0.27.

-         JDBC Driver to the Oracle Database Express Edition 11g

(http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html)

Web services are Web based applications that use open, XML-based standards and transport protocols to exchange data with clients. Web services are developed using Java Technology APIs and tools provided by an integrated Web Services Stack called Metro. The Metro library package is also installed on your computer by Netbeans. 

JavaFX is the next step in the evolution of Java as a rich client platform. It is designed to provide a lightweight, hardware-accelerated Java UI platform for enterprise business applications. With JavaFX, developers can preserve existing investments by reusing Java libraries in their applications. They can even access native system capabilities, or seamlessly connect to server-based middleware applications.

FYI:

You can use also your favorite IDE instead of Netbeans, but you must ensure that the additional packages(Tomcat, Metro), are also installed.

 After having installed all the software and tools, we will have 3 more steps to do, first database operations, then creating the web service in Netbeans, and finally the client part programming, javafx.

1.    Database tasks

The example is about storing information about books, read by me, and retrieving information from database by a given book id, and presenting them by javafx client, through a webservice. In the database we will have a book table, with the fields: Id, Title and Writer. To increment the primary key at every new record, in the book table, we use triggers and sequences in Oracle. You should use, the free SQLDeveloper tool. (http://www.oracle.com/technetwork/developer-tools/sql-developer/downloads/index.html). The sql code for creating a login user, the table, sequence, and trigger, are the following:

Login user

-- Create the user

create user TESTER

  identified by ""

  default tablespace SYSTEM

  temporary tablespace TEMP

  profile DEFAULT

  password expire;

-- Grant/Revoke role privileges

grant dba to TESTER;

-- Grant/Revoke system privileges

grant unlimited tablespace to TESTER;

Create table

-- Create table

create table BOOK

(

  ID     NUMBER not null,

  TITLE  NVARCHAR2(50) not null,

  WRITER NVARCHAR2(100)

)

tablespace SYSTEM

  pctfree 10

  pctused 40

  initrans 1

  maxtrans 255

  storage

  (

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

  );

-- Add comments to the table

comment on table BOOK

  is 'Testing javafx and webservice';

-- Add comments to the columns

comment on column BOOK.ID

  is 'Primary key';

comment on column BOOK.TITLE

  is 'Title of the book';

comment on column BOOK.WRITER

  is 'Writer of the book';

-- Create/Recreate primary, unique and foreign key constraints

alter table BOOK

  add constraint PK_ID primary key (ID)

  using index

  tablespace SYSTEM

  pctfree 10

  initrans 2

  maxtrans 255

  storage

  (

    initial 64K

    next 1M

    minextents 1

    maxextents unlimited

  );

Create sequence

-- Create sequence

create sequence SEQ_BOOK

minvalue 1

maxvalue 9999999999999999999999999999

start with 1

increment by 1

cache 20;

Create trigger

create or replace trigger TRG_BOOK

  before insert on book 

  for each row

declare

  -- local variables here

begin

   IF INSERTING THEN

  IF :NEW.ID IS NULL THEN

   SELECT SEQ_BOOK.NEXTVAL INTO :NEW.ID FROM DUAL;

  END IF;

 END IF;

end TRG_BOOK;

/

2.    Creating the Webservice

Using the Netbeans IDE, to create a webservice, is very easy. First you create a Web Application, by doing: File-New Web Application in Netbeans' Menu. In this demo, we use the Apache Tomcat 7.0.27. as a webserver for our web application. Netbeans 7.2 IDE allows you to choose this webserver, when you create the web application. After the first step we easyly create the webservice, just right clicking on project source and saying, create webservice. Name your webservice(class), WebServcieForJavaFx. Then Netbeans will create you, also a simple “hello” example method, that we will change to the method GetBookInfo. The GetBookInfo() function will retrieve the informations, book title and writer from database, by an ID. The ID will be an input parameter to this method, and the return type of this function will be a special type, created by us: RecordType. Because the program works with Oracle database you must also add the oracle jdbc driver to this project. Right click at the project and at the Properties you can add the ojdbc6.jar file.

First let’s see the special return type, the RecordType java class file, how it looks:

package utils;

/**

 *

 * @author Sipos Lehel

 */

public class RecordType {

    private String Title;

    private String Writer;

   

    RecordType() {

       

    }

    public String getTitle() {

        return Title;

    }

    public void setTitle(String Title) {

        this.Title = Title;

    }

    public String getWriter() {

        return Writer;

    }

    public void setWriter(String Writer) {

        this.Writer = Writer;

    }

   

}

And then the webservice main class will be the following:

package server;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.Statement;

import java.sql.ResultSet;

import javax.jws.WebService;

import javax.jws.WebMethod;

import javax.jws.WebParam;

import utils.*;

/**

 *

 * @author Sipos Lehel

 */

@WebService(serviceName = "WebServiceForJavaFx")

public class WebServiceForJavaFx {

    @WebMethod(operationName = "GetBookInfo")

    public RecordType GetBookInfo(@WebParam(name = "strID") String strID) {

        RecordType answer = new RecordType();

        answer.setTitle("empty");

        answer.setWriter("empty");

       

        try {            

            Class.forName("oracle.jdbc.OracleDriver");

            Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:XE", "tester", "tester");           

            ResultSet rs = null;

            Statement stmt =  con.createStatement();

            rs=stmt.executeQuery("select * from book where ID="+strID);           

            if (rs!=null) {

                rs.next();

                answer.setTitle(rs.getString("TITLE"));

                answer.setWriter(rs.getString("WRITER"));                                         

                rs.close();

            }

            stmt.close();           

        } catch (Exception ex) {

            answer.setTitle(ex.getMessage());

            answer.setWriter("Error occured!");           

        }                                        

        return answer;

    }

}

A webservice publishes it’s method through a WSDL file, and therefore right click in Netbeans, at webservice and say generate WSDL file. Start your webservice, by running this application. You can test the web service information by also, right clicking in Netbeans:

3.    Programming JavaFx – webservice client

To create a javafx application in Netbeans, just simply say, File-New Project-JavaFx-Create JavaFx Application. Call your java main file in this project: WebClientJavaFx.

Creating a webservice client at the second step, is also very easy, just right click your source in the Projects window and say create web service client. Creating your webservice client you will need to point the WSDL location, which you can do by specifying its URL:

In the java source file you can call the Web Service Operation in your start method, by right clicking in the netbeans source editor, and saying Insert Code and then Call Web Service Operation.

We will have 3 components to work with, a button to call the webservice, a label to see the answer, and a field component to bypass the ID input parameter to the webservice method.

Your WebClientJavaFx java file, after programming should look like this:

package webclientjavafx;

import javafx.application.Application;

import javafx.event.ActionEvent;

import javafx.event.EventHandler;

import javafx.scene.Group;

import javafx.scene.Scene;

import javafx.scene.control.Button;

import javafx.scene.control.Label;

import javafx.scene.control.TextField;

import javafx.stage.Stage;

import webclientjavafx.webclient.RecordType;

/**

 *

 * @author Sipos Lehel

 */

public class WebClientJavaFx extends Application {

    Label lbl = new Label("Lehel Sipos read: ");

    TextField fld = new TextField("2");  

    RecordType answ;

   

    @Override

    public void start(Stage primaryStage) {       

        answ = getBookInfo("2");               

        Button btn = new Button();

        btn.setText("Get a book from the shelf");

        btn.setOnAction(new EventHandler<ActionEvent>() {

            @Override

            public void handle(ActionEvent event) {

                answ = getBookInfo(fld.getText());

                lbl.setText("Lehel Sipos read: "+answ.getTitle()+" "+answ.getWriter());

            }

        });               

        Group root = new Group();       

        root.getChildren().add(0,lbl);        

        root.getChildren().add(1,fld);

        root.getChildren().add(2,btn);

        root.getChildren().get(0).setLayoutX(50);               

        root.getChildren().get(0).setLayoutY(10);       

        root.getChildren().get(1).setLayoutX(50);       

        root.getChildren().get(1).setLayoutY(40);       

        root.getChildren().get(2).setLayoutX(50);       

        root.getChildren().get(2).setLayoutY(100);                             

        Scene scene = new Scene(root, 600, 250);       

        primaryStage.setTitle("JavaFx-Webservice example");

        primaryStage.setScene(scene);

        primaryStage.show();

    }

   

    public static void main(String[] args) {

        launch(args);

    }

   

    private static RecordType getBookInfo(java.lang.String strID) {

        webclientjavafx.webclient.WebServiceForJavaFx_Service service = new webclientjavafx.webclient.WebServiceForJavaFx_Service();

        webclientjavafx.webclient.WebServiceForJavaFx port = service.getWebServiceForJavaFxPort();

        return port.getBookInfo(strID);

    }

}

This application can be run also from browsers, if the javafx applet will be a signed jar file, or maybe you change your java.policy security file by adding the following lines to the …jre7\lib\security\java.policy

grant { 

 permission java.security.AllPermission;

};

The running program is showed in the following pictures:

MGWT - A very simple example - click the button

MGWT

MGWT stands for developing mobile applications with GWT and mgwt.
Mgwt works on all kind of mobile devices that support webkit (like iPhone, iPad, iPod, Android, Blackberry, ...)

• Native support for touchevent the GWT Way
• Animations built in with GWT MVP
• lots and lots of widgets
• specific theme for each plattform (iOS, Android, ...)

 Let' se a simple example starting from a Google Web Toolkit(GWT) project:

1. Create a GWT project
2. In your gwt xml file add this line:
   <inherits name='com.googlecode.mgwt.MGWT'/>

3. Add the MGWT library to your project
(It can be downloaded from: http://www.m-gwt.com/ )

4. And your EntryPoint will be this:


public class mobileEntryPoint implements EntryPoint {

    //global variables
    int countI;
    MTextBox lbl;
   
    public void onModuleLoad() {
                //initialization
                lbl = new MTextBox();
                countI=0;
       
                //set viewport and other settings for mobile
                MGWT.applySettings(MGWTSettings.getAppSetting());
                //build animation helper and attach it
                AnimationHelper animationHelper = new AnimationHelper();
                RootPanel.get().add(animationHelper);

                //build some UI
                LayoutPanel layoutPanel = new LayoutPanel();
                Button button = new Button("Hello User!");               
                //for click event
                button.addTapHandler(new TapHandler() {
                    @Override
                    public void onTap(TapEvent event) {
                        countI++;                                               
                        lbl.setText("You clicked: "+countI+" times");
                    }                   
                }) ;                                                                                             
                layoutPanel.add(button);
                layoutPanel.add(lbl);

                //animate at click
                animationHelper.goTo(layoutPanel, Animation.SLIDE);              
    }
}

By using gwt-phonegap and mgwt you can write applications that can be deployed into the app store or the market place with GWT.

JavaFx - Scene Builder

GWT - plugin for Netbeans editor

For using Google Web Toolkit (GWT) under Netbeans IDE, there is a plugin to install:

http://plugins.netbeans.org/plugin/716/gwt4nb

JavaFx - CHART example

We would like to have a chart of the imported fruits. 

Let' see in JavaFx the PieChart diagram:

public class JavaFXApplication1 extends Application {

    public static void main(String[] args) {
        launch(args);
    }
   
    @Override
    public void start(Stage primaryStage) {
       
      primaryStage.setTitle("Chart example");
      ObservableList<PieChart.Data> pieChartData = FXCollections.observableArrayList(
                new PieChart.Data("Grapefruit", 13),
                new PieChart.Data("Oranges", 25),
                new PieChart.Data("Plums", 10),
                new PieChart.Data("Pears", 22),
                new PieChart.Data("Apples", 30));
        PieChart chart = new PieChart(pieChartData);
        chart.setTitle("Imported Fruits");       
       
        StackPane root = new StackPane();
        root.getChildren().add(chart);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
               
    }
}

Java - read from console, dos prompt

The JAVA file is the following, for an example of reading input values from console:

package javaapplication1;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class JavaApplication1 {

    public static void main(String[] args) throws IOException {
       
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
       
        String prompt = "";       
        System.out.println("Enter your name: ");
        prompt = reader.readLine();
        if (prompt.equals("\t"))
            System.out.println("You entered a TAB from your keyboard.");
        else
            System.out.println("Your name is: "+prompt);
       
    }
}

Java - sorting strings with Hungarian characters

        Let's sort some Hungarian strings in alphabetical order:

        String[] words = {"Bruce","Géza","Ákos"};

        Collator c = Collator.getInstance(new Locale("hu"));      
        Arrays.sort(words, c);

        for(int m=0; m<words.length; m++)
            System.out.print(words[m]+", ");

Java - Enumerated types

To enumerate some constant values, and/or associate to them methods or values, we can use enum in java. Enum types in Java are considered like classes, they can have constructors too, can implement interfaces, but can have no descendants. Let see, how we work with enum in java, through an example that classifies programming languages.
Create your own test class, and then test the following code:

    private enum prog_language {
        //enumerated constants
        java(true), c(true), basic(true), php(true), delphi(true), csharp(false), cplus(false);
       
        //fields to associate with the enum types
        private int position;
        private boolean usedbyme;
       
        //constructor
        prog_language(boolean bUsedByMe) {
            usedbyme = bUsedByMe;
        }           
        //getters and setters of the fields
        public int getPosition() {
            return position;
        }
        public void setPosition(int position) {
            this.position = position;
        }          
        public boolean isUsedbyme() {
            return usedbyme;
        }       
    };

.......................................       
        int i = 0;
        for (prog_language p : prog_language.values()) {
            i++;
            p.setPosition(i);
        }                              
        System.out.print(prog_language.valueOf("java").name());      
        System.out.println(" - at position: "+prog_language.valueOf("java").getPosition());
        System.out.println("I am using this language: "+prog_language.valueOf("java").isUsedbyme());

   
 
Enum types can also participate in switch-case statements too.

Java - Data Structures

Data Structure    –    Advantages       –         Disadvantages

Array	Quick insertion (very fast access if index known.)	Slow search,  Slow deletion,  fixed size.
Ordered Array	Quicker search	Slow insertion, Slow deletion, fixed size.
Stack	Provides last-in, first-out access	Slow access to other items
Queue	Provides first-in, first-out access	Slow access to other items
Linked list	Quick insertion, quick deletion	Slow search
ArrayList            (is same as a Vector. Vectors are synchronized, can be thread safe, but slower)	Binary Search, Sort	Slow insertion, deletion
Binary tree	Quick insertion, deletion (if tree remains balanced), and search.	Deletion algorithm is complex
Red-black tree	Quick insertion, deletion (this tree is always balanced), and search.	Complex
2-3-4 tree	Quick insertion, deletion (this tree is always balanced, is good for disk storage progr.), and search.	Complex
Hash table (~arrays)	Very fast access if key known. Fast insertion	Slow deletion, access slow if key not known, inefficient memory usage.
Heap (~LinkedList)	Fast insertion, deletion, access to largest item.	Slow access to other items
Graph	Models real-world situations.	Slow and complex.

                       

Java - Maps / storing values in key-value pair

        Map<String, Integer> mPair = new HashMap<String, Integer>();       

        mPair.put("one", new Integer(1));
        mPair.put("two", new Integer(2));
        mPair.put("three", new Integer(3));
        System.out.println(mPair.values());

        if (mPair.containsKey("two"))
            System.out.println(mPair.get("two"));