Project 6

Software Implementation

Using Test Driven Development

Mission:

You were hired to implement usingJava a Train system simulation, designed by a developer who suddenly left the team. You are provided with the design specification document (Project6-Train-SDS.doc) and unit test suite (tests.zip). You are to assume that design description is correct for what each class and method is supposed to do and so are the JUnit tests and your Java code is supposed to match them.

Objectives:

You must implement the system using the given design and make sure that all the unit tests pass against your code. Your program must implement the complete design to include all the classes, methods, constructors, constants, and attributes, and the input and output specification exactly. You cannot redesign or change the system.

Steps:

Create a new project in Eclipse and import the unit tests (tests.zip) and data files into your projects src. Add JUnit library to your Eclipse project

Note that you will have syntax errors in the tests until you create all the classes

The unit test suite is divided into the basic and advanced tests for each Java class.

You should first implement (for each class) the attributes, constants, and empty methods (method signatures) to pass the basic tests.

Then you should start implementing each method running the appropriate tests against it.

To run an individual test, highlight the test method name, right click on it, select Run As and select JUnit Test

Trains simulate method has been implemented for you. Copy and paste the code in simulate.txt to your Train class.

Run the code and unit tests against them until all defects are fixed

For default file tests under TestSimulatorAdvanced you will need to run them individually with and without that file being on your system (C:/train/customer-data.txt). Check comments for tests which tests require the file and which not

Once all the unit tests are working, create a sample input file and run the program with it. Capture the screenshot of the output

Warning: If you use Scanner for reading console and/or file, do not close it because when you try to use again it will not work.

Resources:

Proj6-MSIT660-GradingCriteria.doc lists the grading criteria

You can use any code examples under My Course Content->Code Examples

Deliverables:

Your program files - all .java files (one java file per class)

Sample data file data.txt

Output screenshot paste into Word doc your-name-Output.docx

----------------------------------------------------------------------------------------------------------------------------------------------------------

Software Design Specification

for

Simple Train Simulator

Version 3.0

Prepared by Leva Kurginyan;

Modified by Dr Rand Mcfadden

<05>

Table of Contents

1. Introduction............................................................................................................................... 1

1.1 Purpose................................................................................................................................... 1

1.2 Intended Audience and Reading Suggestions............................................................................. 1

1.3 Product Scope.......................................................................................................................... 1

1.4 Overview................................................................................................................................. 1

2. Design Considerations............................................................................................................... 2

2.1 Assumptions and Dependencies................................................................................................ 2

2.2 General Constraints.................................................................................................................. 2

2.3 Development Methods.............................................................................................................. 2

3. System Architecture.................................................................................................................. 2

3.1 High level Overview of System Architecture (class diagram)...................................................... 2

4. Human Interface Design........................................................................................................... 4

4.1 Interface description................................................................................................................. 4

4.2 Screenshots of Interface............................................................................................................ 4

4.2.1 Prompt for stops and loop if incorrect................................................................................. 4

4.2.2 Prompt for pathname and loop if not exist........................................................................... 5

4.2.3 Check input data and loop if incorrect................................................................................ 5

4.2.4 Display output as simulation runs....................................................................................... 5

5. Detailed System Design............................................................................................................. 6

5.1 Simulator Class........................................................................................................................ 6

5.2 Train class............................................................................................................................... 8

5.3 Customer class....................................................................................................................... 10

Revision History

Name	Date	Reason For Changes	Version
Leva Kurginyan	07/22/14	Instructors feedback updated to Elevator Simulation	1.1
Renata Rand Mcfadden	07/24/14	Modified for Train Simulation	2.0
Renata Rand McFadden	05/09/2015	Modified for TDD Project	3.0

1. Introduction

1.1 Purpose

This is the Software Design Specification for the simple Train Simulator. This document will define the design of the simulator, by breaking down the project into components to describe in detail what the purpose of each component is and how it will be implemented. It will contain specific information about the expected input, output, and functionality. Also it will explain system constraints, assumptions, dependencies and interface.

1.2 Intended Audience and Reading Suggestions

This Software Design Specification is intended for:

Development team who will develop the first version of the system.

Developers who can review projects capabilities and more easily understand where their efforts should be targeted to improve or add more features to it.

Product testers can use this document as a base for their testing strategy. Also it might be used as a tool for verification and validation of the final product.

1.3 Product Scope

Simple Train Simulator system will be a simple train simulation, implemented with object-oriented approach using Java. It will simulate a train traveling to multiple stops (in a loop starting at stop 1 to stop N) with customers entering and exiting the train. The train will not stop if there are no customers waiting to enter or exit the train at that stop.

User of the program will need to input how many stops the train will have and the absolute path of text file with all customer data. While the simulation is running, it will display data to the console with train stops and customers entering and leaving the train. At the end of the simulation, the program will display how many stops it made to service all customers.

1.4 Overview

The remainder of this document includes 4 chapters.

The second one introduces system constraints and assumptions about the product.

The third chapter gives high level overview of system architecture.

The fourth chapter provides the description of the system interface.

The final fifth chapter provides detailed system design inclooding main data structures, atributes, and metodes used in each class.

2. Design Considerations

2.1 Assumptions and Dependencies

None.

2.2 General Constraints

Implementation environment

Project must be written in Java using Object Orientated approach.

Hardware

None.

2.3 Development Methods

Simple Train Simulator must be implemented using Object Orientated approach.

3. System Architecture

3.1 High level Overview of System Architecture (class diagram)

The three main components of Simple Train Simulator are: Simulator class, Train class and Customer class. Simulator is responsible for prompting and parsing user input data and running simulation. It creates an instance of Train class and N number (depending on data file) of instances of Customer class. It then runs the Train methods for the simulation.

Simulator prompts user for number of stops and the input file with customer data. Parses the file and created a list of customers using Customer class. Creates an instance of Train and runs its methods for the simulation.

Customer stores the four values parsed from file (id, arrival, enter, exit) for the customer. Sets up constants and status variable to determine status where CUST_NOT_PROCESSED means the customer has not been processed yet; CUST_ENTERED means_ the customer is on the train; and CUST_EXITED means the customer was processed and left the train.

Train - stores the number of stops train will have and the customer list. It also has an attribute for storing how many stops the train made as it processed the customers. The Simulator will create an instance of Train and set these values using the constructor. The simulate() method runs the strategy printing the appropriate output. The displayStops method prints the message with the number of stops the train made to process all customers and how long it took.

4. Human Interface Design

4.1 Interface description.

Simple Train Simulator will have text based user interface with textual output and textual prompts where user needs to type in a response.

When program starts, user gets prompted for number of stops the train has on its route: Enter number of stops the train has on its route (must be greater than 1): .

On invalid input, user will get error message Invalid input, try again. " and will be prompted to enter the number of stops again.

On correct input user gets prompted for customer data file name: Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter: .

If file does not exist, user will get error message File not found, try again. " and will be prompted to input the file path again.

If file has non-integer as one of the first four values, user will get error message Each line must have four integers. Try again. and will be prompted to input the file path again.

If any of the data in the customer file is not valid, user will get error message Data in input file is not correct. Try again. Then user will be prompted to enter another file path.

After user inputs all necessary correct information simulation begins.

During simulation information about each step of simulation (current time, current stop, customers entering train and customers leaving train) is printed out for user.

When simulation is done information about number of stops that were made and how long it took is printed out. The display will be Train made x stops and it took y time units to process all customers with x and y the actual values from the simulation

Program terminates.

4.2 Screenshots of Interface

4.2.1 Prompt for stops and loop if incorrect

Enter number of stops the train has on its route (must be greater than 1): 0

Invalid input, try again

Enter number of stops the train has on its route (must be greater than 1):

Enter number of stops the train has on its route (must be greater than 1): n

Invalid input, try again

Enter number of stops the train has on its route (must be greater than 1):

4.2.2 Prompt for pathname and loop if not exist

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

blah

File not found, try again.

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

4.2.3 Check input data and loop if incorrect

# id numbers are duplicate in input file (same for other constraints)

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

C:/train/customer-bad-id.txt

Data in input file is not correct. Try again.

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

# non-integer in the input file

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

C:/train/customer-bad-arrival2.txt

Each line must have four integers. Try again.

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

4.2.4 Display output as simulation runs

For input file (C:\train\customer-data.txt) with contents:

10 1 1 5

11 1 2 5

12 3 3 1

13 10 4 6

Output is:

Enter number of stops the train has on its route (must be greater than 1): 7

Enter absolute path for data file or for default (C:/train/customer-data.txt) press Enter:

Current Time=1 Current Stop=1

Customer enters train: id=10

Current Time=2 Current Stop=2

Customer enters train: id=11

Current Time=3 Current Stop=3

Customer enters train: id=12

Current Time=5 Current Stop=5

Customer exits train: id=10

Customer exits train: id=11

Current Time=8 Current Stop=1

Customer exits train: id=12

Current Time=11 Current Stop=4

Customer enters train: id=13

Current Time=13 Current Stop=6

Customer exits train: id=13

Train made 7 stops and it took 13 time units to process all customers

5. Detailed System Design

5.1 Simulator Class

This class is responsible for:

Prompting user for all necessary inputs

Reading data file and parsing it

Checking for invalid input

Creating and storing instances of Customer class into ArrayList

Creating an instance of Train class

Running simulation by calling Trains simulate method

Attributes None

Methods

Method	Description
main()	Runs the program
void run(int, ArrayList)
int getStopsFromUser()	Prompts user for number of stops, checks for invalid data and re-prompts, returns the valid value of stops
File getInputFile()	Prompts user for input file and checks that file exists. Loops prompting until user gives path for existing file.
ArrayList checkFile(int stops, File)	Parses and checks for invalid data. If file has anything invalid, it returns null list. If file has valid values, creates instances of Customer and creates an ArrayList of type Customer and returns the list

Uses/Interactions

Creates instance of Train class.

Creates instances of Customer class - as many as necessary based on data file.

Simulator class is not used by any other class

Constraints

Number of stops for the train must be entered as numeric (integer) value and greater than 1.

Data file, which is specified by user, must exists and have correct data for each customer.

Customer data constraints:

Each customer must have a unique id, greater than 1, and it must be an integer

The arrival time at the train must be greater than 0 and must be an integer. It represents the time the customer arrives at the train.

The enter stop value must be greater than 0 and an integer. It has to be less than or equal to the highest stop the train has. It representing the stop number of the train where customer wants to enter the train. Stops start at 1 and go up to the N stops that user specified.

The exit stop value must be greater than 0 and integer. It has to be less than or equal to the highest stop the train has. It representing the stop number of the train that customer wants to exit the train.

Customer cannot enter and exit the train at the same stop.

Resources

The only resource that is used by this class is data file specified by user.

Processing

getStopsFromUser(): int

Prompts user to enter number of stops.

Checks input (must be integer > 1) and gives error message if it is not. Loops until correct value is entered.

Returns the obtained value to caller

getInputFile(): File

Loop until the path given is for file that exists

Prompts user for the input file path

If no file is given (user presses enter) then use the default path name (C:/train/customer-data.txt)

Use given path to create File instance

Checks if file exists.

If file does not exist gives an error message and loop until correct path is entered.

Return File instance

checkFile(int stops, File file): ArrayList

Creates empty list (ArrayList list)

In while loop

Reads file line by line

Parses the four integer values per line

Checks data that it meets the above constraints. If data is incorrect, stops parsing, gives error message, and returns null

Creates instance of customer class (using data from single line from data file)

Stores instance of customer into list.

Exits loop when no more lines to read.

Returns list

run(int stops, ArrayList custList):

Create an instance of Train and pass through constructor stops and custList

Call Trains simulate method

Call Trains displayStops method

main() method:

Creates an instance of Simulation class

Creates custList of type ArrayList and assigns null

Calls Simulators getStopsFromUser() method and saves the return value in variable (stops)

Loops as long as custList is null

Calls Simulators getInputFile() method. Save the returned File instance

Call Simulators checkFile() method passing it stops and instance of File. Save returned value in custList

Call Simulators run method passing it the stops and custList

5.2 Train class

This class is responsible for:

Picking up customers

Dropping off customer

Moving train (one stop at a time)

Calculating number of stops and the time it took for train to process all customers made and to print out results.

Class Attributes

Attribute	Description
stops : int	Used to store the number of stops train has on its route.
madeStops: int	Used to store number of stops the train made to process all customers.
currTime: int	Used to store the time for the train made to process all customers.
custList : arrayList	Used to store list of customers to process in the simulation.

Methods

Method	Description
Train(int, ArrayList)	Constructor to pass values of stops and customer list from Simulator and to initialize Trains attributes
simulate()	Runs the train and processes customers entering and exiting the train. Train starts at stop 1 and travels to stop N. The route is a loop so then the train goes to stop 1 again and it keeps running until there are no more customers to process.
displayStops()	Displays the message of how many stops the train made and how long it took to process all customers

Uses/Interactions

The only class that uses Train class is the Simulator class. Train uses Customer class as it processes the list

Constraints

Preconditions all necessary values are passed to instance of Train class by Simulator class (stops, custList).

Processing

Train() constructor:

All attributes are initialized

simulate() method:

Train starts running at current time = 1 and current stop =1.

Make loopAgain = true (Boolean to control the loop)

Loop until no more customers to process Loop for each customer in the list

Check if there is any customers to process (status does not equal Customer CUST_EXITED). If yes then make loopAgain set to true so that when finishes processing this iteration, goes through loop again

Print message with current time and current stop only if there is customer to enter or exit the train

If customer not processed yet and his arrival time is less than or equal to current time and his enter stop is same as current stop, have customer enter the train (customers status gets set to Customer.CUST_ENTERED). Print message about customer entering train.

If customer is in train already (status== Customer.CUST_ENTERED) and exit stop is equal to current stop, have customer exit the train (status gets set to Customer.CUST_EXITED). Print message about customer exiting train.

If a customer entered or exited train, then increment by 1 the madeStop and update currTime

Increment local variable keeping track of time and local variable to keep track of current stop

If current stop == last stop (N), assign 1 to current stop for the train to loop

displayStops() method:

Print message Train made X stops and it took Y time units to process all customers using value of madeStops for X and value of currTime for Y.

5.3 Customer class

This class is responsible for storing and returning (when it is requested) customer information such as customer id, arrival time, enter stop, exit stop, and customers status.

Constants

Constant	Description
CUST_NOT_PROCESSED: static final int	Assigned value of 0 and means customer has not been processed yet
CUST_ENTERED: static final int	Assigned value of 1 and means customer entered the train
CUST_EXITED: static final int	Assigned value of 2 and means customer exited the train and is done processing

Attributes

Attribute	Description
id : int	Used to store customers ID
arrival : int	Used to store customers arrival time at the train
enter : int	Used to store the stop that customer will enter train
exit : int	Used to store the stop that customer will exit train
status : int	Used to track customers status using the constants

Methods

Method	Description
Customer(int Custid, int arrivalTime, int enterStop, int exitStop)	Constructor method to set attributes passed from Simulator It also sets status attribute to CUST_NOT_PROCESSED
void setStatus(int status)	Used to set customers status to the value passed by caller.
int getStatus()	Returns customers current status
int getId()	Returns customers ID
int getArrival()	Returns customers arrival time
int getEnter()	Returns entered stop
int getExit()	Returns exit stop

Uses/Interactions

Customer class is used by Simulator and Train classes.

This class does not use any other classes.

Constraints

All constraints are already described under Simulator class

Processing

All attributes are initialized by constructor method.

When getId() method is called it returns value of id attribute.

When getArrival () method is called it returns value of arrival attribute

When getEnter () method is called it returns value of enter attribute

When getExit () method is called it returns value of exit attribute

When getStatus () method is called it returns value of status attribute

When setStatus(status) method is called it sets passed parameter value as a value of status attribute.