LAB EXERCISE 13: Rainfall Statistics

Goal: In this exercise, you will learn how to:
1. Insert the Main Method (Main Entry Point to the Java Program)
2 Import a Java Class Library
3. Declare Variables and Initialize
4. Create a Method which will return data
5. Create a Method which will accept an argument
6. Create Arrays to store data of the same data type in memory
7. Use the For Loop to allow the iteration and the repetitive execution of code
8. Create an Object from the Class
9. Call the Object’s Method and pass an argument

Program Specifications:
Create an application that allows the user to input each month’s amount of rainfall (in inches) and calculates the total and average rainfall of a year. The total and average rainfall is displayed on the screen.

A. Pre-requisites:
1. Create a folder on your desktop Exercise-13

2. Launch Java EE- Eclipse
Note: You will need to use the Java Perspective Workbench for this exercise

3. Setup your Eclipse Workspace to point to the Exercise-13 folder
a. Select File-> Switch Workspace
b. Browse and select your Exercie-13 folder as your Workspace.

B. Requirements:

1. Create a Java Project and name it as RainfallStatistics

2. Create the first Class that will have the Main Method

a. Name the Class as MainApp

b. Choose the main method to insert into the class

3. Create the second Class that will have the Constructor and Methods

a. Name the Class as Statistics

b. Do not select the main method stub

C. Requirements for the Statistics Class:

1. Insert the import java.util.Scanner class which will allow data to be inputted from the console.

2. Declare the variable- totalRainFall and avgRainFall using the double data type.
Initialize both variables to 0

3. Declare the array statsArray[] using the double data type. This will store each month’s rainfall data.

4. Declare the monthArray[] to store the name of the month. Initialize the values in the array. Below is the code you can copy and paste.

String monthArray[] = {"Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"};

5. Create the Method called getRainFallStats() that will prompt the user to input the data and accumulate the total rainfall.

a. Declare the scanner input class objects - Scanner inputStats = new Scanner(System.in)

b. Used the For Loop to perform the following iteration:
1. Prompt the user to input the rainfall stats in inches for each month (Jan to Dec)
2. Store the monthly rainfall stats in the array
3. Accumulate the total sales using a Running Total

c. Close the scanner input class object - inputStats.close()

d. Return the results - totalRainFall

6. Create the Method called calcAverageRainFall() that will calculate the average yearly rainfall
a. This method should accept the argument parameters (double total)
b. Calculate the avgRainFall = total /12 and return the result value

D. Requirements for the MainApp Class:

1. Add comments (documentation)– Program Description, Author and Date

2. Create the instance of object called rainfall from the Statistics class

3. Call the object’s method - rainfall.getRainFallStats() that will get user data and calculate the running rainfall total. Store the returned result to the rainTotal variable using a double data type

4. Call the object’s method - rainfall.calcAverageRainFall(rainTotal) that will calculate the yearly average rainfall. Pass the rainTotal value as an argument. Store the returned result to the avgYearlyRain variable using a double data type

5. Display the returned result on the console. Below is the code you can copy and paste.

System.out.println();
System.out.print("Total Yearly Rainfall: ");
System.out.format("%.2f",rainTotal);
System.out.println();
System.out.print("Average Yearly Rainfall: ");
System.out.format("%.2f",avgYearlyRain);

E. Test:

1. Save your Java code

2. Compile and run your Java program.

3. Verify there is no syntax, logical or run-time errors.

4. Use the following set of test data to determine if the application is calculating properly:

F. Submit your exercise in the Canvas Lab Exercise #13 Drop Box.

1. Submit the screen shot of the Eclipse Workbench window showing the Console output screen.
You can use Paint (save as JPG) or Word to paste the screenshot.

2. Zip up and submit the compressed RainfallStatistics subfolder that is in the Exercise-13 folder.
NOTE: Right click on the subfolder and select Send to “Compress Folder”. The file will have a file extension of .zip.