WebSphere Studio Application Developer Version 5 Programming Guide part 34 pps

304 WebSphere Studio Application Developer Version 5 Programming Guide  On the Struts Settings page, select Override default settings : – Change the Struts version to 1.1 (beta2). – Enter itso.strutsweb as the Default Java package prefix. – Leave itso.strutsweb.resources as the Java package for the resource bundle. – Leave ApplicationResources as the resource bundle name. – Click Finish (Figure 10-8). Click OK when prompted to repair the server configuration. This action adds the new Web project to the server configuration. Figure 10-8 Setting Struts properties The new Web project is configured with:  An application resources file: Java Source\itso.strutsweb.resources.ApplicationResources.properties  An action servlet (in web.xml)  A configuration file (struts-config.xml) and six tag libraries (struts-xxxx.tld) in Web Content\WEB-INF  The Struts runtime classes (struts.jar and dependent JAR files) in Web Content\WEB-INF\lib. we used the Struts beta support Chapter 10. Developing Struts applications 305 Copying the facade We will use the same model and facade as in Chapter 7, “Developing Web applications” on page 179. The easiest way to get the facade is by copying:  Select the itso.bank.facade package in the ItsoProGuideBasicWeb project and Copy from the context menu.  Select the Java Source folder in the ItsoProGuideStrutsWeb project and Paste from the context menu. Alternatively you can create the itso.bank.facade package manually and import the Banking class from the \sg246957\sampcode\dev-struts\initial\facade directory. Importing RedBank Web content We want to mirror the image and style sheet of the ItsoProGuideBasicWeb project in the new ItsoProGuideStrutsWeb project:  Open the Web perspective, J2EE Navigator view, select the ItsoProGuideStrutsWeb\Web Content directory and Import (context).  Select File system as source to import from and then click Next .  Click Browse and locate: \sg246957\sampcode\dev-struts\initial\Web Content  Expand the Web Content directory and select the check box next to it.  Click Finish (Figure 10-9). Notes:  If you create a Web project with Struts 1.02 support, there will be only one JAR file (struts.jar) in the lib directory, because Struts 1.02 includes all dependent classes in this single JAR. In Struts 1.1 these classes are now split into multiple JAR files.  Although not necessary for our simple application, you would probably want to upgrade the Struts JAR file to a later version than the 1.1 beta 2 shipping with Application Developer 5.0. At the time of writing, the latest version of Struts is 1.1 Release Candidate 1.  The Struts action servlet is configured (in web.xml) to intercept all requests with a URL ending in .do (the servlet mapping is *.do). This is common for Struts applications, but equally common is using a servlet mapping of /action/* to intercept all URLs beginning with /action. 306 WebSphere Studio Application Developer Version 5 Programming Guide Figure 10-9 Importing sample code Updating ApplicationResources.properties The wizard created an empty ApplicationResources.properties file for us and we have to update it with the texts and messages for our application. While developing Struts applications, you will usually find yourself having this file open, because you will typically add messages to it as you go along writing your code. Figure 10-10 shows an extract of this file. Chapter 10. Developing Struts applications 307 Figure 10-10 ApplicationResources.properties (extract)  In the Web perspective, expand Java Source and then open the itso.strutsweb.resources.ApplicationResources.properties file.  Replace then contents of the file with the contents in: \sg246957\sampcode\dev-struts\initial\ApplicationResources.properties  Press Ctrl-S to save the file and then close the editor. The exception classes we use extend the itso.bank.exception.BankException class and have a method called getMessageKey. This method returns the key for the error message so that we can retrieve the clear text message from the ApplicationResources.properties file when an error has occurred. An example of the getMessageKey method is: public String getMessageKey() { return "error.customerDoesNotExistException"; } Creating the Struts Web diagram We take a top-down approach to design the Web application by laying out all the components in a Web diagram:  Select the WEB-INF folder and New -> Other -> Web -> Struts -> Web diagram . Click Next . Enter strutsbank as the file name and click Finish . # Optional header and footer for <errors/> tag. errors.header=<P><font color="#ff0000"><strong><ul> errors.footer=</ul></strong></font></P> error.missing.customerId=<li>You must enter your customer ID. error.missing.accountNumber=<li>You must select an account to work with. error.invalid.customerId=<li>Invalid customer ID. Please try again. error.invalid.amount=<li>Invalid amount. Please correct your entry. text.pageTitle=ITSO Bank text.welcome=Welcome to the ITSO Bank text.customersAccounts={0}'s Accounts prompt.enterCustomerId=Please, enter your customer ID: prompt.account=Select the account: prompt.transaction=Select the transaction: 308 WebSphere Studio Application Developer Version 5 Programming Guide  The Web diagram editor opens on the strutsbank.gph file (.gph is the file type for Web diagrams).  Notice the icons in the tool bar: The icons on the right are to place new components into the empty diagram. The icons are connections, actions, form beans, JavaBeans, JSPs, sub-diagrams, and Struts modules. Adding the components Use the icons in the toolbar to add four JSP pages, three actions, and two form beans on the empty surface (Figure 10-11):  When you drop a JSP page or an action, you can change its name to the name shown in Figure 10-11.  When you drop a form bean, you are prompted for a name and scope. Enter customerInfoForm and transactionForm as names and select request as scope. Figure 10-11 Web diagram with initial components Components in gray are not yet implemented, meaning they are only available in the Web diagram and not as an underlying file such as a Java class or JSP. Chapter 10. Developing Struts applications 309 Designing the application flow When the components are laid out, it is time to connect them to define the flow of the application. Figure 10-12 shows the layout with connections. Figure 10-12 Web diagram with components connected  Select index.jsp and select Connection (context). A line appears connecting index.jsp to the mouse cursor. Click the listAccounts action to complete the connection. A dotted line appears from index.jsp to listAccounts. (You can also use the Connection icon and click the two items to connect.)  Connect listAccounts.jsp to the accountDetails action, the accountDetails.jsp to the performTransaction action, and the listTransactions.jsp to the accountDetails action.  Connect the listAccounts action to listAccounts.jsp. Connecting an action to a JSP page creates a forward, and you are prompted to enter a name for it. Overtype <new> with the name success. The listAccounts action can then lookup the listAccounts.jsp by referring to the name success.  Connect the accountDetails action to the accountDetails.jsp and enter success as the name for this forward as well.  The performTransaction action uses four different forwards depending on which transaction was performed: – Connect the performTransaction action to listTransactions.jsp and call this forward listTransactions. 310 WebSphere Studio Application Developer Version 5 Programming Guide – Add three forwards from performTransaction back to accountDetails.jsp and call the forwards deposit, withdraw, and transfer, respectively.  Connect the customerInfoForm to the listAccounts action and also to the accountDetailsAction. The customerInfoForm is used by both actions.  Connect the transactionForm to the performTransaction action.  Save the Web diagram by pressing Ctrl-S. Implementing the Struts Web diagram When the Web diagram is laid out, it is time to start implementing the components. This can be done in a different order, and the support you get from Application Developer’s Struts tools depends on the order you choose:  You can implement the form beans first. When you later implement the JSPs, you can choose which fields from the form beans should be present on the pages.  You can implement the JSPs first. When you later implement the form beans, you can choose which fields from the JSP pages should be added to the form beans as properties. We choose to implement the form beans first to have full control over their contents and structure. Developing the form beans We start by implementing the customerInfoForm form bean:  Double-click the customerInfoForm form bean in the Web diagram. This opens up the New ActionForm Class dialog as shown in Figure 10-13. Tip: You can select a component in the diagram and from the context menu select:  Change Path to change the name of a JSP or action  Edit the forward name to change the name of a connection  Change Description to add descriptive text to any components To improve the layout of the application flow, you can drag components to another spot and you can rearrange connections by dragging their middle point. Chapter 10. Developing Struts applications 311 Figure 10-13 New ActionForm Class wizard Application Developer automatically generates a Struts form bean class called itso.strutsweb.forms.CustomerInfoForm and implement skeleton methods for its reset and validate methods. The default values in the dialog are fine, so click Next to proceed.  On the next page we can select the fields from the JSPs we want to include in the form bean. Because we do not yet have any implemented JSPs, we cannot use this feature, so just click Next (Figure 10-14). 312 WebSphere Studio Application Developer Version 5 Programming Guide Figure 10-14 Selecting fields from JSPs  On the third page of the wizard we can enter the fields we want our form bean to hold. Click Add and add each of the following fields (Figure 10-15): customerNumber String customerName String (firstname lastname) accountNumber String (after selection) accountNumbers String[] (list retrieved from customer) validateKey String (1 or 2, which action) Figure 10-15 Adding form bean fields Click Next . Note: Make sure you press Enter after entering the text in each field. Otherwise, when you click Next , Application Developer may not include the last field you updated. Chapter 10. Developing Struts applications 313  On the next page (Figure 10-16) you are prompted to add a mapping for the form bean to the Struts configuration file. Accept the defaults and click Finish . Figure 10-16 Adding struts-config.xml mapping The form bean wizard creates a new Java class extending the org.apache.struts.action.ActionForm class and opens it up in the editor.  Replace the validate method (not the whole class) with the code shown in Figure 10-17. The code is available in: \sg246957\sampcode\dev-struts\initial\forms\CustomerInfoForm.txt Figure 10-17 CustomerInfoForm validate method public ActionErrors validate( ActionMapping mapping, HttpServletRequest request) { ActionErrors errors = new ActionErrors(); // Validate the customerNumber if ("1".equals(validateKey)) { if (customerNumber == null || customerNumber.trim().length() == 0) errors.add( ActionErrors.GLOBAL_ERROR, new ActionError("error.missing.customerId")); else if (customerNumber.trim().length() != 3) errors.add( ActionErrors.GLOBAL_ERROR, new ActionError("error.invalid.customerId")); } // Validate the accountNumber - defer to action class if ("2".equals(validateKey)) {} return errors; } . 304 WebSphere Studio Application Developer Version 5 Programming Guide  On the Struts Settings page, select Override default settings : – Change the Struts version to 1.1 (beta2) Struts applications, but equally common is using a servlet mapping of /action/* to intercept all URLs beginning with /action. 306 WebSphere Studio Application Developer Version 5 Programming Guide Figure. ID: prompt.account=Select the account: prompt.transaction=Select the transaction: 308 WebSphere Studio Application Developer Version 5 Programming Guide  The Web diagram editor opens on the strutsbank.gph file (.gph