WebSphere Studio Application Developer Version 5 Programming Guide part 50 pps

This chapter provides information on the following topics: ? Introduction to the Visual Editor for Java ? Sample GUI ? Setting up your sample project ? Launching the Visual Editor ? Visu

Creating a Web service from a session bean

Creating a Web service from an EJB session bean is very similar to the process for a JavaBean There are only a few differences Let us go through the process

in abbreviated fashion:

򐂰 In the J2EE Hierarchy view, expand the ItsoProGuideEJB project

򐂰 Select the BankEJB session bean and New -> Other -> Web Services -> Web Service

򐂰 The type of Web service is now preselected as EJB Web service Select Generate a proxy and Test the generated proxy

򐂰 Select the ItsoProGuideWebServ project as the Web project

򐂰 Leave all the defaults on the EJB configuration

򐂰 Leave all the defaults on the identity The URI is:

http://tempuri.org/itso.ejb.model.facade.BankEJB

򐂰 Leave all the methods selected

򐂰 Leave the proxy class to proxy.soap.BankEJBProxy

򐂰 Leave the sample test application folder as sample/BankEJB Make sure the client project is ItsoProGuideWebServClient

򐂰 Click Finish

The code is generated and the test client opens (Figure 13-18)

Implementing a real client application

We provide a very simple client consisting of one JSP to execute the deposit and

withdraw methods of the Banking service:

򐂰 Import the TestBankingWebService.jsp into the ItsoProGuideWebServClient

project (Web Content folder)

򐂰 The main logic is shown in Figure 13-19:

– A proxy bean (proxy.soap.ClientBankingProxy) to invoke the Web service is allocated using <useBean>

– The parameters from the form are retrieved and tested

– Depending on the Submit button, either the deposit or withdraw method of the Web service is invoked

– After the banking operation, the getAccount method is invoked so that we can display the account information

– The rest is HTML code with JSP tags to display the form with input fields and push buttons, and to display the resulting account information

– Note that the proxy and the Account classes are imported

The client proxy makes coding of a real client very simple

Notes:

򐂰 If you encounter runtime errors, restart the server

򐂰 Methods that return collections are not supported in the test client, because an instance cannot be created

򐂰 The methods of our session bean return arrays of objects; these are very well supported by SOAP encoding

<jsp:useBean id="proxy" class="proxy.soap.ClientBankingProxy"

scope="session"></jsp:useBean>

<%! String accid = null;

String amount = null;

String deposit = null;

String withdraw = null;

java.math.BigDecimal amountD = new java.math.BigDecimal(0.00); Account account = new Account();

%>

<%

accid = request.getParameter("accountid");

amount = request.getParameter("amount");

deposit = request.getParameter("deposit");

withdraw = request.getParameter("withdraw");

if ( accid != null && amount != null && !accid.trim().equals("")

&& !amount.trim().equals("") ) { amountD = new java.math.BigDecimal(amount);

if ( deposit != null ) proxy.deposit(accid, amountD);

if ( withdraw != null ) proxy.withdraw(accid, amountD);

account = proxy.getAccount(accid);

}

%>

<h1>Banking Web Service Test</h1>

<FORM action="/ItsoProGuideWebServClient/TestBankingWebService.jsp" method="post">

<TABLE>

<tr><td>Enter an account number:</td>

<td><INPUT type="text" name="accountid" size="20"

value="<%= accid %>"></td></tr>

<tr><td>Enter an amount:</td>

<td><INPUT type="text" name="amount" size="20"></td></tr>

<tr><td>&nbsp; </td>

<td><INPUT type="submit" name="deposit" value="Deposit">

<INPUT type="submit" name="withdraw" value="Withdraw"></td></tr>

</TABLE>

<h2>Account information</h2>

<TABLE border="1">

<tr><td>Account number: </td><td><%= account.getId() %> </td></tr>

<tr><td>Account type: </td><td><%= account.getType() %> </td></tr>

<tr><td>Account balance: </td><td><%= account.getBalance() %></td></tr>

Figure 13-20 Client JSP invoking a Web service

Summary

In this chapter, we introduced Web services We then showed an example of using Application Developer to generate a Web service from an existing JavaBean Finally, we showed how easy it was to create a Web service client using the built-in wizard

More information

The 2003 IBM Redbook WebSphere Version 5 Web Services Handbook, SG24-6891, goes into thorough detail about the concept of SOA as well as Web Services for WebSphere Version 5 It also contains examples using Application Developer Version 5

Additional information about using and creating Web Services is available from the online help included in Application Developer

Chapter 14. Developing GUI applications

Application Developer 5 introduces the Visual Editor for Java (hereafter called Visual Editor) that lets developers build graphical user interfaces (GUIs) based

on the JavaBeans component model

In this chapter we introduce you to the Visual Editor and develop a sample GUI, which lists the content of a table in a DB2 database and has an action that writes the selected value back to a text field This GUI is runnable as a JavaBean and

as a Java application

This chapter provides information on the following topics:

򐂰 Introduction to the Visual Editor for Java

򐂰 Sample GUI

򐂰 Setting up your sample project

򐂰 Launching the Visual Editor

򐂰 Visual Editor look and feel

򐂰 Customizing the appearance of the Visual Editor

򐂰 Changing the default Java Editor

򐂰 Working with the Visual Editor

򐂰 Adding data to the JavaBean

򐂰 Adding additional methods to the sample GUI

򐂰 Writing event handling code

򐂰 Running and testing JavaBeans

򐂰 Running the sample outside of Application Developer

14

Introduction to the Visual Editor for Java

The Visual Editor for Java is a code-centric editor that helps you design applications containing a graphical user interface (GUI) It is based on the JavaBeans component model and supports visual construction using either the Abstract Windows Toolkit (AWT) or Swing For more information concerning Swing and AWT, see the either Application Developer’s help manual or Sun’s Web site:

http://java.sun.com/products/jfc/index.html The Visual Editor allows you to compose class files visually Using the Visual Editor, you can drag beans from different palettes, manipulate them in the Design view, and edit their properties in the Properties view The Visual Editor also includes a Source view where you can both see and modify the generated Java code You can make changes in either the Source view or in the Design view

The new Visual Editor provides similar function as the earlier VisualAge for Java Visual Composition Editor Unlike VisualAge for Java, the Visual Editor is a code centric editor, so you have to use its embedded Java editor to write event handling logic

Sample GUI

The sample GUI we develop in this chapter is shown in Figure 14-1 The sample GUI displays a list with the last names of customers that are stored in the sample

EJBBANK database The GUI also provides a push button action that retrieves the corresponding first name of the customer and writes the first name to a text field

in the GUI

Note: JavaBeans is basically a portable, platform independent, reusable

component model When talking about a JavaBean in this chapter, we mean a reusable software component that can be visually manipulated in builder tools

Figure 14-1 Sample GUI

By creating the sample GUI, you should learn how to work with the new Visual Editor and how to compose and add visual components, change their properties, add event handling code, and run the GUI

Setting up your sample project

To demonstrate the capabilities of the Visual Editor, we set up a new project Therefore we create a new Java project and name it ItsoProGuideGui See

“Creating a Java project” on page 94 for a description of how to create a new Java project

Once this is done, we create a Java package named itso.gui “Creating Java packages” on page 99 provides information regarding this issue Our new project skeleton is shown in Figure 14-2

Figure 14-2 Project skeleton You also have to update the Java build path for this project You do this by selecting the ItsoProGuideGUI project and Properties from the context menu Then you select the Java Build Path entry and the Libraries tab (Figure 14-3) Click Add Variable, select DB2JAVA and confirm both dialogs with OK

JList bean JButton bean

JTextField bean JLabel bean

See “Creating and working with a Java project” on page 94 for more information about the Java build path

Figure 14-3 Libraries settings for the sample project After having created the project, we create a new class and launch the Visual Editor

Launching the Visual Editor

The Visual Editor allows you to create and modify application GUIs by manipulating beans in a WYSIWYG (what you see is what you get) editor There are two ways to launch the Visual Editor:

򐂰 Create a visual class, which is automatically assigned and opened with the Visual Editor

򐂰 Create a Java class from scratch and open the class with the Visual Editor

In this example we create a visual class as described in the first step above

Create a visual class

To create a visual class, select File -> New -> Other -> Java -> Visual Class or, even easier, select the itso.gui package and New -> Visual Class from the context menu

Enter CustomerGUI in the Name field, make sure the package is set to itso.gui, select Panel from the extension list, select Swing—our sample class will inherit from the javax.swing.JPanel class—and select to have a main method created (Figure 14-4)

Figure 14-4 Create a visual Java class

We have a choice of using Swing or AWT as GUI framework

Table 14-1 shows a brief description of the user interface classes that can be selected in the New Java Class dialog