Web Application Services Practice Session #2

Transcription

1 INTRODUCTION In this lab, you create the BrokerTool Enterprise Application project that is used for most of the exercises remaining in this course. You create a servlet that displays the details for a customer stored in a javax.servlet.http.httpsession. Figure.1: The trader.web.customerdetails Servlet Output Page 1

2 EXERCISE 1: Implementing the Customer View in the CustomerDetails Servlet This exercise contains the following sections that describe the tasks to create the BrokerTool Enterprise Application and the CustomerDetails servlet and to make the CustomerDetails servlet the default page: Task 1 Creating an Enterprise Application Project Task 2 Creating the CustomerDetails Servlet Task 3 Configuring, Deploying, and Testing the Application PREPARATION This exercise assumes that the application server is installed. Page 2

3 Task 1 Creating an Enterprise Application Project 1. From the menu select File then New Project. 2. Under Categories, click Enterprise. 3. Under Project, click Enterprise Application. 4. Click the Next button. 5. Enter the following information for the new Enterprise Application project: Project Name: BrokerTool Project Location: /export/home/student/projects Set as Main Project: (checked) 6. Click the Next button. 7. Include the following information in The Server and Settings dialog: Server: GlassFish v2 J2EE Version: Java EE 5 Create EJB Module: BrokerTool-ejb (Checked) Create Web Application Module: BrokerTool-war (Checked) 8. Click the Finish button. A folder for BrokerTool, BrokerTool-ejb, and BrokerTool-war are created. Task 2 Creating the CustomerDetails Servlet 1. Right-click the BrokerTool-war icon. 2. Select New then Package. 3. Enter trader for the package name. 4. Click the Finish button. 5. Copy classes from the BrokerTool_SE project to the trader package in the BrokerTool-war project. a. Open the BrokerTool_SE project. b. Open Source Packages, then trader. c. To copy a class, right-click the class you want to copy in the BrokerTool_SE trade package. Next, click on the target trade package in the BrokerTool project. Right-click the target package and select Paste. d. Copy the following classes: trader.brokerexception trader.brokermodel trader.brokermodelimpl trader.customer trader.customershare trader.stock 6. Close the BrokerTool_SE project. 7. Create a new servlet in the BrokerTool-war project named CustomerDetails. 8. In the name and location dialog, enter the following information: Class Name: CustomerDetails Location: Source Packages Package: trader.web Page 3

4 9. Click the Next button. 10. In the Configure Server Deployment Dialog enter the following information: Add information to deployment descriptor (web.xml) (Checked) Servlet Name: CustomerDetails URL Pattern: /CustomerDetails 11. Click the Finish button. 12. Modify the web.xml configuration file of the BrokerTool-war project to make CustomerDetails the default Welcome Page. a. Open the Configuration Files folder. b. Double-click web.xml. c. Select the Pages tab. d. Remove index.jsp as the welcome file and replace it with CustomerDetails. 13. In the CustomerDetails servlet, import the classes in the trader package. 14. For the CustomerDetails servlet, perform the following steps. a. Ensure that the content type is set to text/html. b. Using the HttpResponse s PrintWriter, create a navigational menu along the top that includes links to the following pages (created in subsequent exercises): <a href= CustomerDetails >Customer Details</a> <a href= CustomerController >All Customers</a> <a href= Stocks.jsp >Stocks</a> c. Check the a request object for an attribute named customer (case sensitive). Assign the value of the attribute to a variable named cust of type Customer. If cust is not null, use the getname, getaddr, and getid methods of Customer to assign values to the String variables name, address, and id. A Customer object will be placed in the request scope by the servlet created in the next exercise. d. Create a form for a customer s details (see Figure.1). The default values for the form elements should be equal to the data in the Customer object if it was found in the request scope. The form can be laid out using any method you want, such as tables or CSS. The form should have the following properties: The action should be CustomerController. The method should be GET. An HTML text input field with a name of customername. An HTML text input field with a name of customeridentity. An HTML text input field with a name of customeraddress. Four submit buttons with the name submit and the values Get Customer, Update Customer, Add Customer, and Delete Customer. e. If the Customer object was found in the request scope, then print a URL to that customer s portfolio. Use the getid method of Customer to retrieve an ID that is passed as an HTTP GET form parameter to the PortfolioController development in the next exercise. Use the following example: <a href= PortfolioController?customerIdentity= + id + >View Portfolio</a> f. Using an if statement, attempt to retrieve a String attribute named message (case sensitive), from the HttpServletRequest. This message is created by other classes when errors occur. Display the message string in red below the customer details form. g. Close the PrintWriter. Page 4

5 Task 3 Configuring, Deploying, and Testing the Application Complete the following steps: 1. Make sure the BrokerTool enterprise application project is open. 2. Open the BrokerTool-ejb project if it is not open. 3. Build the BrokerTool enterprise application. Correct any errors. 4. Deploy the BrokerTool enterprise application. 5. Run the application or test the servlet by pointing a browser at: You should see an empty customer details form. Page 5

6 EXERCISE 2: Implementing Controller Components This exercise contains the following sections that describe the tasks to create the CustomerController servlet and the BrokerDelegate java class: Task 1 Creating a Business Delegate Class Named BrokerDelegate Task 2 Creating the CustomerController Servlet Task 3 Creating the PortfolioController Servlet Task 4 Configuring, Deploying, and Testing the Application PREPARATION This exercise assumes that the application server is installed. Page 6

7 Task 1 Creating a Business Delegate Class Named BrokerDelegate 1. In the BrokerTool-war project, create a new Java class named BrokerDelegate in the trader package. The new class should have the following characteristics: Class Name: BrokerDelegate Location: Source Packages Package: trader 2. The BrokerDelegate class implements the Business Delegate and the Singleton design patterns. The Singleton design pattern ensures that a class is only instantiated once inside a Java virtual machine. The following code snippet is an example of the Singleton design pattern. public class BrokerDelegate { private static BrokerDelegate instance= new BrokerDelegate(); public static BrokerDelegate getinstance() { return instance; } private BrokerDelegate() {} } 3. The BrokerDelegate must use a BrokerModel to execute business operations. To obtain a reference to a BrokerModel object, add an instance-level variable in BrokerDelegate of: private BrokerModel model = BrokerModelImpl.getInstance(); 4. The delegation of business logic in BrokerDelegate allows you to change the BrokerModel in the future without having to change the CustomerController. Implement the following methods in BrokerDelegate: public Customer addcustomer(string customerid, String name, String address) throws BrokerException; public CustomerShare addcustomershare(string customerid, String stocksymbol, int quantity) throws BrokerException; public void deletecustomer(string customerid) throws BrokerException; public CustomerShare[] getallcustomershares(string customerid) throws BrokerException; public Customer[] getallcustomers() throws BrokerException; public Stock[] getallstocks() throws BrokerException; public Customer getcustomer(string customerid) throws BrokerException; public Stock getstock(string symbol) throws BrokerException; public Customer updatecustomer(string customerid, String name, String address) throws BrokerException; public CustomerShare updatecustomershare(string customerid, String stocksymbol, int quantity) throws BrokerException; Page 7

8 Task 2 Creating the CustomerController Servlet 1. Create a new servlet in the BrokerTool-war project. 2. In the Name and Location dialog, enter the following information: Class Name: CustomerController Location: Source Packages Package: trader.web 3. Click the Next button. 4. In the Configure Server Deployment Dialog enter the following information: Add information to deployment descriptor (web.xml) (Checked) Servlet Name: CustomerController URL Pattern: /CustomerController 5. Click the Finish button. 6. Import the trader package. 7. Import javax.servlet.requestdispatcher. 8. Use the following steps to code the processrequest method: a. Remove any code that sets the content type or uses the response s PrintWriter. b. Create an instance of the BrokerDelegate named delegate using the BrokerDelegate.getInstance method. c. Retrieve the request form parameter values for customeridentity, customername, customeraddress and submit. Assign the values to String variables id, name, address, and submit. d. If one of the submit buttons in the CustomerDetails servlet was pressed to invoke this servlet, perform the following actions: If the Get Customer submit button was pressed, use the BrokerDelegate to look up the customer with the customeridentity request parameter. Store the customer as a request attribute named customer (case sensitive). If the Update Customer submit button was pressed, use the BrokerDelegate to update the customer with the ID of the customeridentity request parameter to have the values of customername and customeraddress. Store the customer as a request attribute named customer (case sensitive). If the Add Customer submit button was pressed, use the BrokerDelegate to create a new customer with the customeridentity, customername, and customeraddress request parameters. Store the customer as a request attribute named customer (case sensitive). If the Delete Customer submit button was pressed, use the BrokerDelegate to delete the customer with the customeridentity request parameter. Use exception handling to deal with any errors that might occur when using the BrokerDelegate. If exceptions occur, call the Exception class getmessage method and store the value in a request attribute named message. Use a RequestDispatcher to forward the response to the CustomerDetails servlet. RequestDispatcher dispatcher = request.getrequestdispatcher("customerdetails"); dispatcher.forward(request, response); e. If a submit button was not used to invoke this servlet, perform the following actions: Page 8

9 Use the BrokerDelegate to retrieve an array of all customers. Store the array of all customers as a request attribute named customers. Use a RequestDispatcher to forward the response to AllCustomers.jsp. RequestDispatcher dispatcher = request.getrequestdispatcher("allcustomers.jsp"); dispatcher.forward(request, response); Task 3 Creating the PortfolioController Servlet The PortfolioController servlet is used in the next module. It is designed to retrieve a customer s portfolio and forward that data to a Portfolio.jsp for display. 1. Create a new Servlet in the BrokerTool-war application. 2. In the name and location dialog, enter the following information: Class Name: PortfolioController Location: Source Packages Package: trader.web 3. Click the Next button. 4. In the Configure Server Deployment Dialog enter the following information: Add information to deployment descriptor (web.xml) (Checked) Servlet Name: PortfolioController URL Pattern: /PortfolioController 5. Import the trader package. 6. Import javax.servlet.requestdispatcher. 7. Implement the processrequest method as follows protected void processrequest(httpservletrequest request, HttpServletResponse response) throws ServletException, IOException { String customerid = request.getparameter("customeridentity"); BrokerDelegate delegate = BrokerDelegate.getInstance(); try { CustomerShare[] shares = delegate.getallcustomershares(customerid); Customer customer = delegate.getcustomer(customerid); request.setattribute("shares", shares); request.setattribute("customer", customer); } catch(brokerexception be) { request.setattribute("message", be.getmessage()); } RequestDispatcher dispatcher = request.getrequestdispatcher("portfolio.jsp"); dispatcher.forward(request, response); } Page 9

10 Task 4 Configuring, Deploying, and Testing the Application 1. Build the BrokerTool enterprise application. Correct any errors. 2. Deploy the BrokerTool enterprise application. 3. Run the application or test the servlet by pointing a browser at: 4. You will see an empty customer details form. You should be able to enter a known customer identity, such as , and retrieve information for that customer. Try all the buttons on the customer details page except the View Portfolio button if it is shown. Fix any errors that occur. Page 10