Chapter 91© copyright Janson Industries 2011 Java Design Concepts ■ JSP’s ■ MVC MVC ■ Beans...

Chapter 9 1© copyright Janson Industries 2011

Java Design Concepts

■ JSP’s

■MVC

■Beans

■ JSP Tags



■How do you like having to type in all that HTML for servlet?

■Make a few source code entry mistakes?

■Page Designer and JSP’s make it easier


JSP Example

▮ Java Server Pages are comprised of HTML with embedded Java statements, JSP tags, or JSTL tags HTML code

Java codeHTML codeJava codeHTML code▮ JSP Java statement types

▮ Scriptlet▮ Expression▮ Declaration▮ Directive


Java Statement Tags

▮ Java scriptlet syntax: <% java statement %>

▮ Java expression syntax: <%= java statement %>

▮ Java declaration syntax: <%! java statement %>

▮ Java directive syntax: <%@ java statement %>


JSP Example<HTML>

<HEAD>

<TITLE>

JSP Example

</TITLE>

</HEAD>

<BODY BGCOLOR="#FFFFFF">

<% for (int i = 0; i < 5; i++) { %>

<P>Howdy from the JSP example.</P>

<% } %>

<P>The current date and time is:

<%= new java.util.Date() %>

</P>

</BODY>

</HTML>

A lot less code than a

servlet!

Scriptlet

Expression

Scriptlet


Java Statement Tags

▮ Java declaration allows you to define a method:

<%! private void error() {System.out.println(“Error,

Error!”); } %>

▮ Java directive allows you to specify JSP wide instructions:

<%@page import = “java.io.*” %>


JSP Example

▮ Problem with Java statements – not XML compliant

▮ Use JSP tags:

<jsp:scriptlet> for (int i = 0; i < 5; i++) { </jsp:scriptlet>

<jsp:expression> new java.util.Date() </jsp:expression>

<jsp:declaration> private void error() {System.out.println(“Error, Error!”); }

</jsp:declaration>

<jsp:directive.page import = "java.io.*" />


To Create, click on MyWeb, File, New, Web Page

Give JSP a name (JSPEx), click on JSP in the Basic Templates area then click Finish


Initial code inserted by RAD


In Navigation Pane, right click JSPEx and select Run on

Server

Cut and paste example code (from earlier slide) over RAD code


Do same using JSP tags not Java Statement tagsSolution


JSP

▮ JSP’s are actually converted into Servlets by the JSP container

▮ For instance, in Tomcat, for each .jsp file there is a .java and .class file created in

/Tomcat 5.0/work/standalone/localhost/test

▮ I.e. if I created Studio.jsp, Tomcat will create the files Studio$jsp.java & Studio$jsp.class


So, really, the advantage to JSP’s is ease of

construction for the programmer


JSP

▮ For JSPs, RAD generates a class file with the same name as the JSP preceded by an underscore

▮ _JSPEx.class

▮ The class file is stored in the WAR

▮ RAD doesn't provide access or even display the file (as far as I can tell!)


JSP

But using Computer you can drill into the server and find it


RAD JSP

▮ Design pane provides a GUI to build JSP’s

▮ Drop and drag Web page GUI components

▮ Property definition panes

▮ Format Java statements

▮ Insert predefined routines (scriptlets)

▮ For example, create a JSP called RAD

© copyright Janson Industries 2011Chapter 9 17

Insert this text

RAD JSP


To Insert a Scriptlet, position cursor on page, click JSP, Insert Scriptlet


Display the Properties view of the Scriptlet


In properties pane specify Java codeIn this example, inserted the beginning of a

loop


Insert another scriptlet with the rest of the for

loop


Run on the server

Should have a <br> tag to insert a line in each loop

© copyright Janson Industries 2011Chapter 9 23

RAD JSP

Save the code


Refresh the browser


▮ Need to be a Java programmer to implement▮ Cumbersome syntax▮ Knowledge of object oriented

programming

▮ No coding standards ▮ for (int i = -200 ; i < -100; i=i+20) {

▮ JSTL Tags are the solution (more later)

Java Statement Problems


JSP In Class Assg

▮ Create a JSP that uses a loop to print the system date five times



■MVC design pattern for server-based applications

♦ Model

♦ View

♦ Controller


MVC

■ Model – classes that access/store data and perform business functions

■ View – classes that:♦ Enable users to input data/instructions♦ Format and display results

■ Controller – classes that manage the model and view

Means creates


Java MVC Example

DB

Data andinstructions

Data

View

User


Applicationresults

DataModel

Data

View

Controller


MVC

■ You can see the MVC pieces in the client app

■ However:

♦ Separation of pieces difficult with client technology

♦ Initially, user must interact directly with Controller


Customer

CustomerApp Model

CustomerFrameUser

run CustomerAppinstruction

EnterCustInfocreates

EmptyFrame

Frame (with data)& Display instruction

data

CustomerFramewith data

Controller

1

2

3

4

5

8

6

View

cust

Client App MVC Example

data 7

View Controller


Server Side MVC Example

JavaBean

JavaBean

DB

Controller

Model

JSP’s

View

UserHTML (response)

WebPages

ViewServlet

Data

Data

Data

Data



Employee MVC Example

EmpExtractor EmployeeEmpServlet

Controller Model

DispEmpInfoJSP

View

User

HTML (response)

RequestResponse

DispEmpGrossJSP

DispEmpTaxAmtJSP

Request

Employee

View

EnterEmpInfoForm

Data

Data


Employee Example

■ EmpServlet acted as the Controller

■ The JSPs and EmpExtractor were the View

■ Employee was the Model

■ The View created the Model


MyWeb Example

Func2Servlet

Customerobject

FuncServlet

co

CustServlet

User

Functions.html

SaleServlet

Data

Cust orSale.html

Cust.html

HTML (response)With Cust info

Sale.html

HTML (response)With Sale info

ControllerModel

View

requestresponse

coData


Java MVC Example

■ The current thinking is to separate the GUI from the programming logic

♦ Have “graphic designers” create the View (e.g. html and html of the JSPs)

♦ Programmers define the controller (servlets) & business logic (Model) as java beans

♦ JSPs access java beans

►No java code in JSPs, use tags to access beans


MVC Advantages

■ Separating html development from program development cuts down on

♦ Duplicate programming code (in web page, legacy interface, new interfaces, etc.)

♦ Errors

■ Cheaper “resources” develop interface rather than the more expensive programming personnel


MVC Advantages

■ Separating business logic and controller from interface means:

♦ New interfaces can be easily added►Web Services►Text messaging►EDI►Telephony

♦ Changes to DBMS only affect Model


Java MVC Example


Data

View

User


Applicationresults

DataModelView

Controller

User

Phone View


Java MVC Example

■ Many shops make legacy code part of the model and create servlets and JSPs for view and controller portion

■ Some shops recode all the model/legacy in Java


What is a Java Bean

■ A convention/standard for classes

♦ A public Java class

♦ Has a default null constructor

■ Usually has getter/setter methods for each private bean variable (i.e. each property) defined as follows:

♦ public VariableType getVariableName()

♦ public void setVariableName (VariableType x)


What is a Java Bean

■ But guess what?

■ On the server, you can define (just about) any class as a bean

♦ Just won’t be able to access the properties if you don’t have getters and setters


Server Beans

■ Many categories of Server beans:

♦ Entity – associated with a DB table, EJB

♦ Session – last for length of session (duration of browser-server communication)

♦ Request – goes with request

►(Also Page and Application)

■ Can be created/defined by either JSPs or Servlets


Server Beans

■ The Servlet or JSP has to: ♦ Identify the bean

■ Identifying the bean means♦ Giving the bean a name♦ Tying the bean to a Java class/object♦ Defining a bean type/scope

■ Once created, Servlets or JSPs can: ♦ Set a bean parameter/property ♦ Get a bean result/property


JSP Tags

■ In servlet, create object and tie to session (or request, or page, or app) by defining object as an attribute of the session:

Customer Cust = new Customer(); HttpSession sess = req.getSession();

sess.setAttribute("CustBean", Cust);

■ In JSPs, Bean tags used to work with beans: <jsp:xxx> </jsp:xxx>

■ Identify a bean and tie to a java class file with a useBean tag:

<jsp:useBean id=“CustBean“ class=“Customer“>

</jsp:useBean>


Accessing a Bean in a Servlet

■ Set: CustBean.setCustName(req.getParameter(“CustNameTF"));

■ Get:

CustBean.getContactPerson();

■ Because it’s a session bean, any servlet invoked during browser sess can access


■ Set and get bean properties with the Bean tags getProperty and setProperty♦ Name is name of bean

♦ Property is property name

■ setProperty used to set property value

■ getProperty used to get results

<jsp:setProperty name=“CustBean" property=“custName” param=“CustNameTF”/>

<jsp:getProperty name=" CustBean " property=“contactPerson" />

Accessing a Bean in a JSP


Java Bean Example

■ Servlet code: CustBean.setCustName(req.getParameter(“CustNameTF"));

■ Same as jsp tag:

■ Servlet Code: CustBean.getContactPerson();

■ Same as jsp tag:

<jsp:setProperty name=“CustBean" property=“custName” param=“CustNameTF”/>

<jsp:getProperty name=" CustBean " property=“contactPerson" />


Java Bean Example

▮ Of course, class must have set/get methods matching the property names

▮ public String getContactPerson(){...}


Java Bean Sale Example

When data entered into Sale.html, want to see....


Notice the formatting: date & time, line for each item


...total in the Sale.jsp



▮ Need a new class called Tx (transaction)

▮ Stores all sale info▮ item, qty, price, customer name

▮ Calculates total $ for sale

▮ Returns receipt info (getReceipt method)

▮ The new servlets, bean, and JSPs…


Sale Example

SaleServlet

Txobject

FuncServlet

TxBean

User

Functions.html

Sale.jsp

Creates

Cust orSale.html

Sale.html

HTML (response)with receipt info

ControllerModel

View

Redirects ReceiptInfo

Sale info


Java Beans and Servlets

▮ To create the bean in Sale servlet

▮ Create a Tx object

▮ Get a Session object from the request object

▮ Define the Tx object as a session attribute▮ TX object is a session bean


Tx object

▮ Need private variables for properties

▮ Then getters and setters for each property

private StringBuffer custName;

private StringBuffer itemName;

private int qty;

private double price;


Tx object▮ Will overload all the setters to

accept Stringspublic void setPrice(String d) {

this.setPrice(Double.parseDouble(d));}

public void setQty(String i) {

this.setQty(Integer.parseInt(i));}

public void setCustName(String string) {

StringBuffer sb = new StringBuffer(string);

this.setCustName(sb);}

public void setItemName(String string) {

StringBuffer sb = new StringBuffer(string);

this.setItemName(sb);}


Java Bean Example

▮ We won’t build the getReceipt method yet

▮ Instead we’ll CALTAL▮ Create Sale servlet to:

▮ Create Tx object and set the CustName property value (from the request)

▮ Define the bean TxBean▮ Redirect to Sale.jsp

▮ Create Sale.jsp to▮ Retrieve the customer name from TxBean

(using tags)▮ Display customer name


CALTAL Sale

Txobject

TxBean

User Sale.jsp

Creates

Sale.html(with all info)

HTML (response)with CustName

ControllerModel

View

CustName

CustName

Sale(Servlet)

Redirects


Java Bean Example

▮ Sale servlet:▮ 1: Create Tx object assign to variable txBean ▮ 2: Set the CustName property▮ 3: Define TxBean as a session bean▮ 4: Redirect to Sale jsp

import javax.servlet.http.HttpSession;

Tx txBean = new Tx();

txBean.setCustName(req.getParameter("CustName"));

HttpSession sess = req.getSession();

sess.setAttribute("TxBean", txBean);

resp.sendRedirect("Sale.jsp");

3:1:

2:

3:

3:

4:


Java Bean Exampleimport java.io.IOException;

: : : : :

import javax.servlet.http.HttpSession;

: : : : :

import javax.servlet.http.HttpServletResponse;

public class Sale extends HttpServlet implements Servlet {

Tx txBean = new Tx();

public void doGet …{…}

public void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {

txBean.setCustName(req.getParameter("CustName"));

HttpSession sess = req.getSession();

sess.setAttribute("TxBean", txBean);

resp.sendRedirect("Sale.jsp");

}

}


Java Bean Example▮ In Sale.jsp let RAD generate bean tags to:

▮ Retrieve the cust name from TxBean

▮ Display customer name

Create JSP, insert textThen click:

JSP, Insert Get Property


Notice property name begins with a lower case

letter


Must tie Sale.html to Sale servlet

Select the form

In Properties view,

click action button

Select servlet


Select Sale

Chapter 9 67© copyright Janson Industries 2011Time to test

Also, make sure Post is selected


Run Sale.html on server

Enter a customer nameClick the Submit button


Connections all work!! Now:

Change Sale servlet to set all properties

Add methods to Tx to:calc totalreturn formatted receipt

Change Sale.jsp to display receipt


txBean.setItemName(req.getParameter("ItemName"));

txBean.setPrice(req.getParameter("Price"));

txBean.setQty(req.getParameter("Qty"));

▮ Change Sale servlet to set all properties▮ Notice Strings are passed for all parms

▮ Add function to Tx to:▮ calc total: getTotal()▮ return formatted receipt: getReceipt()

Java Bean Example


Java Bean Example

▮ getTotal() not too tough

public double getTotal(){

double total = price * qty * 1.06;

return total;

}


Java Bean Example

▮ getReceipt() a little more involved▮ When this info inserted

▮ Want to see…


Notice the formatting: date & time, line for each item

Java Bean Example


Java Bean Example

▮ Tx needs:

▮ Date and time formatters▮ Currency formatter▮ Date object▮ Date and time properties w/ setters and

getters▮ Date and time properties must be initialized▮ getReceipt will generate the HTML for the

formatting


Java Bean Example

▮ Tx needs:▮ Date and time formatters▮ Currency formatter▮ Date object

import java.text.DateFormat;

import java.text.NumberFormat;

import java.util.Date;

private Date d = new Date();

private DateFormat dfMedium = DateFormat.getDateInstance(DateFormat.MEDIUM);

private DateFormat tfShort = DateFormat.getTimeInstance(DateFormat.SHORT);

private NumberFormat cf = NumberFormat.getCurrencyInstance();


Java Bean Example

▮ Tx needs:▮ Date and time properties ▮ w/ setters and getters

private String date = null;

private String time = null;

public String getDate() {

return date; }

public String getTime() {

return time; }

private void setDate() {

date = dfMedium.format(d); }

private void setTime() {

time = tfShort.format(d); }


Java Bean Example

▮ Tx needs to:▮ Initialize the date and time

properties

▮ Have a getReceipt method that generates the HTML and info in the correct formatting

public Tx() {

this.setDate();

this.setTime();

}


Java Bean Example

Easiest way to generate the HTML is to create the page in Page Designer with static text and

formatting


Then copy the HTML source into the bean and

modify

Java Bean Example


Java Bean Examplepublic String getReceipt(){

String receipt = null;

StringBuffer sb = new StringBuffer();

sb.append("<div align='center'><table border='0'>");

sb.append("<tbody><tr>");

sb.append("<td align='center'>");

sb.append("<font size='4' color='#000000' face='Verdana'> ");

sb.append("TNT Salvage</font><br>");

sb.append("<font size='3' color='#000000' face='Arial'>");

sb.append(this.getDate() + "<br>");

sb.append(this.getTime() + "</font></td>");

sb.append("</tr>");

for (int i = 1; i <= this.getQty(); i++){

sb.append("<tr>");

sb.append("<td><font color='#0000a0'>" +

this.getItemName() + " " +

cf.format(this.getPrice()) + "</font></td>");

sb.append("</tr>");

}

Date/time, item name, and price inserted for static

text

Loop using getQty inserted

Change html " to '


Java Bean Examplesb.append("<tr>");

sb.append("<td align='center'><br>" +

"<font size='3' color='black' face='Arial'>" +

"Total Sale Amount: " +

cf.format(this.getTotal()) + "</font></td>");

sb.append("</tr>");

sb.append("<TR>");

sb.append("<td align='center'>" + this.getCustName() + "<br>");

sb.append("Thanks for shopping with us</td>");

sb.append("</tr>");

sb.append("</tbody>");

sb.append("</table></div>");

receipt = String.valueOf(sb);

return receipt;

}

Must convertsb to String and

return the HTML

Sub real data for static

text


Change Sale.jsp to get receipt property and delete static text and formatting


Java Bean Example


Sale Bean Example

Txobject

FuncServlet

TxBean

Functions.html

Sale.jsp

Creates

Cust orSale.html

Sale.html


ControllerModel

View

Redirects ReceiptInfo

Sale info

User

Sale(Servlet)


Sale Example

■ However, we have violated MVC!!

■ The TX class is creating the view

♦ getReceipt returns a web page/html – that’s the view's job!

♦ Should have a JSP get TX properties and format!


JSPs

▮ Will create new JSP called SaleJSP

▮ SaleJSP will get the info and format the receipt using:

▮ JSP standard action tags

▮ Bean tags


Sale Example

Sale(Servlet)

Txobject

FuncServlet

TxBean

User

Functions.html

SaleJSP

Creates

Cust orSale.html

Sale.html


ControllerModel

View

Redirects Propertyvalues

Sale info


JSPs

<jsp:getProperty name=“TxBean" property=“custName"/>

<jsp:getProperty name=“TxBean" property=“price"/>

▮ Use JSP getProperty tag to access the bean

▮ Can type in the above code or use Page Designer


Add a table with 6 rows 1 col with static text

More JSP Tags


Click Get Property and click 2nd row


Make sure the bean type is session, then specify Bean and Property names, click OK


JSP tag icon displayed

JSP tag result can be formatted by selecting the tag and clicking

FormatThen delete static text "date"


HTML and JSP tags that were generated


Time to test: Run Sale.html on server

Change Sale to redirect to SaleJSP


More JSP Tags

To test, enter info and click submit


More JSP Tags

Need to add tags to get other properties


More JSP Tags


Now, when the above is entered:


There are JSTL tags that allow looping To use the bean property qty (to control the

loop) the tag requires EL (Expression Language)

Of course, getTotal() & getPrice should be changed to return a formatted value plus

there’s no loop


▮ Create CustJSP:

▮ Access the Customer bean

▮ Display the customer info using bean tags

▮ Change Func2Servlet to create CustBean and redirect to CustJSP

In class assg 2


MyWeb Currently

Func2Servlet

Customerobject

FuncServlet

co

CustServlet

User

Functions.html

Data

Cust orSale.html

Cust.html

HTML (response)With Cust info

ControllerModel

View

requestresponse

coData


In class assg 2

Func2Servlet

Customerobject

FuncServlet

CustBean

User

Functions.html

CustJSP

Creates

Cust orSale.html

Cust.html


ControllerModel

View


Cust info

Solution


Looping with JSTL tags

■ The JSTL (Java Standard Tag Library) provides a forEach tag for looping

■ We could cheat and add to SaleJSP...

<c:forEach begin="1" end="2">

html and/or content to be repeated</c:forEach>


Since there are multiple items need a <br> at end


But, of course, this will always show the item twice regardless of

the qtyWant to loop the qty number of

times


Expression Language

■ Created for easy access to beans and properties (don’t need tags)

■ Syntax is: ${beanname.property}

■ EL is part of JSP not JSTL♦ i.e. EL can be used apart from JSTL tags

■ For example, adding the following : The item qty is: ${TxBean.qty}


Then save and refresh the browser


Get rid of text and EL then substitute the EL for 2 in the for

each tag’s end value

Results in...


Save and go back in the browser and change quantity to 4 then

click Submit


Other JSP And JSTL Tags

■ There are several useful JSP tags

♦ jsp:include – places a file’s content in a JSP

■ And JSTL tags for conditional logic♦ <c:if test=“condition”> body </c:if>♦ <c:choose>

►<c:when test=“condition”> body </c:when>►<c:when test=“condition”> body </c:when>

♦ <c:choose>

<jsp:include page=“footer” flush=“true”/>


A file in the project (footer) has an HTML snippet that defines a footer table to appear

at the bottom of every page


... add the include to the JSP, save the source ...


... refresh the browser


JSTL Tags and EL

▮ EL allows:

▮ Easy access to beans and implicit objects

▮ pageContext, request, response, param

▮ Implicit objects created and provided by server

▮ Use of all Java comparison operators (==, <, >, etc.) in EL condition definition


If tag and EL

▮ Allow JSP to do one thing on GET and another on POST (i.e. when the user responds)

▮ if tag with EL<c:if test=‘$

{pageContext.request.method==“GET”}’>Display initial page with form

</c:if>

▮ Notice no .equals when evaluating string!


JSTL if/when & EL Example

<c:if test=‘${pageContext.request.method==“POST”}’><c:choose>

<c:when test=‘${param.functionLB == "Display"}'><jsp:forward page="DispEmpInfoJSP.jsp"></jsp:forward>

</c:when><c:when test=‘${param.functionLB == "Gross"}'>

< jsp:forward page ="DispEmpGrossJSP.jsp"></jsp:forward>

</c:when><c:when test=‘${param.functionLB == "TaxAmt"}'>

< jsp:forward page ="DispEmpTaxAmtJSP.jsp">

</jsp:forward></c:when>

</c:choose></c:if>


▮ Create a CustJSP2 that:

▮ Accesses CustBean bean using EL instead of getProperty bean tags

▮ Change Func2Servlet to redirect to CustJSP2

In class assg 3


In class assg

Func2Servlet

Customerobject

FuncServlet

CustBean

User

Functions.html

CustJSP2

Creates

Cust orSale.html

Cust.html


ControllerModel

View


Cust info

Solution


▮ Customers will be able to order from phones

▮ Of course, need the new phone app with its View

▮ But watch how much we have to change our current app to add that view

New Mobile View


User runs app on phone…


…enters data, clicks button…


…gets this “receipt”


▮ The phone app will send a post request (just like our web app)

▮ However, the customer name will be proceeded by the text mobilePhoneOrder:

▮ The controller (Sale) will check for the text and if it is a mobile order will simply return the total

New Mobile View


Web-based Sale App

Sale(Servlet)

Txobject

FuncServlet

TxBean

User

Functions.html

SaleJSP

Creates

Cust orSale.html

Sale.html


ControllerModel

View


Sale info


Mobile Sale App

Txobject

PhoneSale

TxBean

User

Saleinfo

Creates

Salereceipt

ControllerModel

Sale info

Mobile View

Sale info

Sale total

Sale(Servlet)

Sale total

postrequest

response


Web/Mobile Sale App

Txobject

PhoneSale

TxBean

User

Saleinfo

SaleJSP

Creates

Salereceipt

Sale.html


ControllerModel

WebView


Sale info

Mobile View

Sale info

Sale total

Sale(Servlet)

Sale total


New Mobile View

import java.io.PrintWriter; : : : : :public class Sale extends HttpServlet implements Servlet { : : : : : public void doPost(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException { : : : : : sess.setAttribute("TxBean", TxBean);// new code for phone order view StringBuffer custNameSB = new StringBuffer(req.getParameter("CustName"));// checks if it’s a mobile phone order if (custNameSB.length() >= 17 &&

custNameSB.substring(0, 17).equals("mobilePhoneOrder:"))


New Mobile View

{// sets Customer name correctly

txBean.setCustName(custNameSB.substring(17));resp.setContentType("text/html");try {

PrintWriter out = new PrintWriter(resp.getOutputStream());

// gets the total from the bean and imbeds into the responseout.println(txBean.getTotal());out.close();

} catch (Exception e) {System.out.println("Sale Servlet failed: ");e.printStackTrace(); }

} else {// its not a mobile order so invoke the web view

resp.sendRedirect("SaleJSP.jsp"); } }}


New Mobile View

TxBean

PhoneUser

Creates

Post request

response(with Total)

Controller ModelView

Sale infoSale(Servlet)

Total

Txobject

▮ Notice how in the phone architecture the view does not access the model

▮ The controller acts a buffer between the two


Mobile App

▮ The Mobile App (PhoneSale) screens defined with XML

▮ For example, this is the receipt screen

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" >

<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:orientation="horizontal" >


Mobile App

▮ The Mobile App (PhoneSale) screens defined with XML▮ For example, this is the receipt screen

<TextView android:id="@+id/nameTV" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="TNT Salvage" /> </LinearLayout>


<TextView android:id="@+id/itemTV" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" /> </LinearLayout>



Mobile App


<TextView android:id="@+id/custTV" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="" /> </LinearLayout>


<TextView android:id="@+id/footerTV" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:text="Thanks for shopping with us" /> </LinearLayout>

</LinearLayout>


Mobile App Java Code


package com.phone.sale;

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.util.ArrayList;import java.util.List;import org.apache.http.HttpResponse;import org.apache.http.NameValuePair;import org.apache.http.client.HttpClient;import org.apache.http.client.entity.UrlEncodedFormEntity;import org.apache.http.client.methods.HttpPost;import org.apache.http.impl.client.DefaultHttpClient;import org.apache.http.message.BasicNameValuePair;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.EditText;import android.widget.TextView;


Mobile App


public class PhoneSaleActivity extends Activity {/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);// Displays the order entry screensetContentView(R.layout.main);

}// Called when button clickedpublic void doClick(View arg0) {// Retrieves the text specified in the EditTextsEditText custNameET = (EditText) findViewById(R.id.nameET);String custName = custNameET.getText().toString();EditText itemNameET = (EditText) findViewById(R.id.itemET);String itemName = itemNameET.getText().toString();EditText qtyET = (EditText) findViewById(R.id.qtyET);String qty = qtyET.getText().toString();EditText priceET = (EditText) findViewById(R.id.priceET);String price = priceET.getText().toString();BufferedReader in = null;


Mobile App


try {// Creates a client and request objectHttpClient client = new DefaultHttpClient();HttpPost request = new HttpPost(

"http://sth-radsrv-01.student.fccj.org:9080/MyWeb/Sale");

// Creates a list and populates it with the entered dataList<NameValuePair> postParameters = new

ArrayList<NameValuePair>();postParameters.add(new BasicNameValuePair("CustName",

custName));postParameters.add(new BasicNameValuePair("ItemName",

itemName));postParameters.add(new BasicNameValuePair("Price", price));postParameters.add(new BasicNameValuePair("Qty", qty));// Creates a form and ties the parameter list to the formUrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(

postParameters);// Ties the form to the requestrequest.setEntity(formEntity);// Executes the request and captures the responseHttpResponse response = client.execute(request);// Creates a reader tied to the responsein = new BufferedReader(new

InputStreamReader(response.getEntity().getContent()));


Mobile App


// Displays the receipt screensetContentView(R.layout.receipt);TextView itemTV = (TextView) findViewById(R.id.itemTV);// Reads the response and uses the text in the msgitemTV.setText("You've purchased " + qty + " " + itemName

+ "(s) for a total of $" + in.readLine());TextView custTV = (TextView) findViewById(R.id.custTV);// Displays the customer namecustTV.setText(custName);in.close();

} catch (Exception e) {e.printStackTrace();

} finally {if (in != null) {try {in.close();

} catch (IOException e) {e.printStackTrace();

}}

}}

}

Chapter 91© copyright Janson Industries 2011 Java Design Concepts ■ JSP’s ■ MVC MVC ■ Beans...

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Transcript of Chapter 91© copyright Janson Industries 2011 Java Design Concepts ■ JSP’s ■ MVC MVC ■ Beans...