Object-Oriented Programming (OOP)seg.ece.upatras.gr/Courses/MIM/Labs/3rdLab/LegoIn... · Object-Oriented Programming (OOP) The RPN Calculator ... diagram. The constituent components

Object-Oriented Programming (OOP)The RPN CalculatorWS 2010/11 Lecture

Kleanthis ThramboulidisVisiting Professor

Software Engineering Group

Electrical & Computer Engineering

University of Patras, Greece

[email protected]

[email protected] of Saarland

Nov 2010, Saarbrucken, Germany.

Η RPN Calculator example application

� Develop a program for the system to accept expressions based on the Polish reverse notation and calculate their values.

3 6 + 8 6 - * (3+6) * (8 -6)

©Kleanthis Thramboulidis “Lego Construction” Approach ‹#›2

� Design Constraint� Stack has to be used to store operands.

AgendaAgenda

� “Lego construction” approach

� Repository of components

� Program as an aggregation of existing components


components

� Mechanisms to integrate components

� The need for new objects

�� Mechanisms to Build new Mechanisms to Build new componentscomponents

� Case study: The RPN calculator

“Lego construction” approach“Lego construction” approach


“Lego construction” approach“Lego construction” approach

Requirements from the implementation environment

Repository of Repository of componentscomponents


Mechanisms to Mechanisms to Integrate componentsIntegrate components

Mechanisms to Build new componentsMechanisms to Build new components

Repository of componentsRepository of components

� JDK now contains 1.600 APIs� 200 offered in 95

� 500 offered in Java 1.1

� Includes 15 core class librariesapplet net accessibility


� applet net accessibility

� awt rmi swing

� beans security corba

� io sql text

� lang math util

Java Basic Library


1st step

Use the classes Double and Stack of the basic library of Java to develop a Java program for the system to be able to calculate the value of the expression using the stack


the stack12.0 24.0 +=

Using BlueJ

http://www.bluej.org/The interactive Java environment


The program (1st version)public class MyProg{

public static void main(){Double d1 = new Double(20);System.out.println("d1="+d1);Double d2 = new Double(40);

Stack<Double> st = new Stack<Double>();


Stack<Double> st = new Stack<Double>();st.push(d1);st.push(d2);

Double d3 = st.pop();Double d4 = st.pop(); st.push(new Double(d3+d4));System.out.println("sum is="+st.pop());

}

Draw the object interaction diagram

The constituent components

Stack

Repository New Components

MyProg

Edit-time vs. run-time


Double

System

MyProg

Object Interaction Diagram


public class MyProg{public static void main(){

Double d1 = new Double(20);System.out.println("d1="+d1);Double d2 = new Double(40);

Stack<Double> st = new Stack<Double>();

Increase modularity


Stack<Double> st = new Stack<Double>();st.push(d1);st.push(d2);

Double d3 = st.pop();Double d4 = st.pop(); st.push(d3+d4);System.out.println("sum is="+st.pop());

}

2nd Version – Constituent Components

Stack

Repository New Components

MyProg


Double

System

MyProg

Adder

Build new ComponentAdder

class Adder{public static void operate(){

Double d3 = st.pop();Double d4 = st.pop();


Double d4 = st.pop(); st.push(new Double(d3+d4));

}}

Integrate componentsMyProg

Adder

public class MyProg{public static void main(){


Stack<Double> st = new Stack<Double>();st.push(d1);st.push(d2);……

?


Adder……System.out.println("sum is="+st.pop());

}


Double d3 = st.pop();Double d4 = st.pop(); st.push(new Double(d1+d2));

}}

Flow of control ?

?

Source code (2nd version)public class MyProg{public static Stack<Double> st;public static void main(){




st = new Stack<Double>();st.push(d1);st.push(d2);

Adder.operate();System.out.println("sum is="+st.pop());

}

public static void operate(){Double d3 = MyProg.st.pop();Double d4 = MyProg.st.pop(); st.push(new Double(d1+d2));

}}

The graphical user interface


This is an instance of the class CalculatorGui that is included in the file CalcGuiV1Exer6.jar

Constructor: CalculatorGui(Operand op);

Τα components

Calc

Adder

CalcGuiV2Exer8.jar


Double

Stack

Operand

Who is creating these objects?

How do they communicate?

Constructor for CalcGuiV2Exer8: CalculatorGui(Operand op, Adder add,

Subtracter sub, Multiplier mul, Divider div, ResultPresenter rp){

UML class diagram


Ορισµός της κλάσης Calc

class Calc {

//data members ?

// methods ?


// methods ?

public static void main() {

?

}

}

Τhe components for the + operation

Adder


Double

StackHow do they communicate for the program to provide the plus functionality?

Object Interaction Diagram for +

user st:Stack

pop()

ad:Adder

operate()

:Double

?


pop()

push()

new Double()

The Adder class

class Adder {public void operate() {Double d1 = Calc.st.pop();Double d2 = Calc.st.pop();Double d3 = new Double(


Double d3 = new Double(d1.doubleValue() +d2.doubleValue());

Calc.st.push(d3);}

}

RPN Calculator project


BlueJ Project

MyCalculatorGui

public class MyCalculatorGui extends CalculatorGui {

public MyCalculatorGui(Operand op, Adder add, Subtracter sub, Multiplier mul, Divider div, ResultPresenter rp){


ResultPresenter rp){super(op, add, sub, mul, div, rp);}

}





Updated class diagram

Is there any Gen/Spec relationship?


Documents

Object-Oriented Programming (OOP)seg.ece.upatras.gr/Courses/MIM/Labs/3rdLab/LegoIn... · Object-Oriented Programming (OOP) The RPN Calculator ... diagram. The constituent components