Blood Alcohol Consumption Calculator Phase 2

All of your Alice programs have been using objects already. And the predefined function and procedure methods in Alice are equivalent to instance methods for those objects in Java. You also defined your own methods within an Alice class, which had to be applied to a specific object in order to run.

This assignment will apply the same concepts to Java. You will create a new class, and use the new class to create an object in Java. Methods defined within the new class (instance methods, similar to the Alice procedure and function methods) will be called using the dot (.) operator, to send a message to the object.

WARNING: This assignment will be more challenging than the previous assignments, so make sure to start early and allocate enough time to complete it, including time you might need to seek any necessary help.

Problem Summary

Suppose you wanted to modify your BAC Calculator from Java programming assignment 3. You could:

• Store all the previous data about one drinker as data fields within an object
• Add a drinker identification field
• Revise the calculation methods to be instance methods within the objects class
  • NOTE: This will eliminate the need to pass the drinkers data into the methods via parameters.

Since you will be modifying your BAC Calculator program from Java Assn 3, make sure you use your instructors feedback to fix any mistakes from Java Assn 3 before you submit Java Assn 4.

Overview of Program

This program will contain two classes, in two separate files within your project:

• A new Drinker class to define the data fields and methods for a Drinker object, containing:
  • Five data field (attribute) definitions for a Drinker object
  • A constructor method to create a Drinker object
  • Five setter methods to set the values for all of the data fields
  • Three getter methods to get the values of two of the data fields
  • An instance method to compute the volume distribution for men.
  • An instance method to compute the volume distribution for women.
  • An instance method to compute and display the current BAC.
• The main BACcalculator class, modified to define only 3 methods, containing:
  • A main method to display the program description, create an object, read the inputs from the user, and call the other methods.
  • A static method to display a description of what the program will do.
  • A static method to display drinkers information.

Program Requirements

Modify the program you wrote for Java Assn 3, as follows:

1. Define an additional Java class (File | New File | Java Class) named:

Drinker

Within the Drinker class, define the following private data fields to store properties about the person drinking:

• drinker identifier (String)
• weight in kilograms
• height in meters
• number of drinks consumed
• elapsed time since drinking began in hours

Remember that all private data fields defined at the class-level can be accessed by any method within the same class (without parameter passing).

Also within the new Drinker class, you will define instance methods that can be used with an object of the Drinker class, as follows:

• Define a default constructor with no parameters that will create the object with the following initial data values set:
  Drinker identifier set to "" (an empty String)
  Height and weight, both set to 0.0
  Number of drinks consumed and elapsed time, both set to 0
• Create setters for each data field, as follows:
  • Setter for drinker identifier
    Input parameters will be two Strings:
    the drinker’s last name
    the drinker’s 10-digit phone number, including dashes (e.g. 333-333-3333)
    
    Use the built-in Java String methods to uppercase the last name, and then extract the first 3 letters of the last name and concatenate them with the last 4 digits of the phone number to create a unique identifier for the drinker.
    Set the data field to this value.
  • Setter for weight
    Input parameter will be weight in pounds
    Define and use a local constant: the number of pounds in one kilogram (2.20462)
    Method will convert the parameter weight to kilograms and then set the weight data field to that value.
    
  • Setter for height
    Input parameter will be height in inches
    Define and use a local constant: the number of inches in one meter (39.3701)
    Method will convert the parameter height to meters and then set the height data field to that value.
  • Setter for number of drinks consumed
    No input parameters
    Use descriptive prompt and read number of drinks consumed
    Set the data field to the value input by user
  • Setter for hours elapsed since drinking started
    No input parameters
    Use descriptive prompt and read hours passed while consuming the drinks
    Set the data field to the value input by user
• Create getters for the following data fields in the Drinker class.
  • Get the drinker identifier
  • Getter for number of drinks consumed
  • Getter for hours elapsed since drinking started
  • Each getter should return the data fields current value.
• Move the volume distribution calculation (methods 2 and 3) in Java Assn 3 from the BACcalculator class to the new Drinker class. Then modify the methods, so they can be used as instance methods in the new Drinker class, as follows:
  • Eliminate the static keyword (since they will now be used with objects)
  • Eliminate the parameter lists (since they will now use data fields).
  • Modify the formulas, so that they will directly use the object data fields, instead of parameters.
• Move the BAC calculation (method 4) in Java Assn 3 from the BACcalculator class to the new Drinker class. This method will be modified to calculate and display the BAC, instead of returning the BAC. Modify the method, as follows:
  • Change the method header to indicate nothing will be returned.
  • Eliminate all parameters, except the volume distribution and metabolic rate to use.
  • Add a third parameter: a gender string (which will contain either male or female)
  • Modify the conversion formula to convert the data field weight in kilograms to grams (instead of the previous conversion from pounds to grams) and store the new value. Then use the new value in the BAC formula.
  • After calculating the current BAC, display a description, including the gender, and the BAC value to 3 decimal places. Only one line will be displayed (see next page for examples).
    
    NOTE: No decision statements will be necessary to do this!
    
    For example, if the gender parameter contains the word “male” and the current BAC is 0.0933333333, the output will be:

    a male has a current BAC of approximately 0.093

    But if the gender parameter contains the word “female” the output will be:

    a female has a current BAC of approximately 0.093

2. Within the original BACcalculator class that contains the main method:

• Make sure you deleted the old static calculation methods (2 4) from the BACcalculator class when you moved them to the Drinker class.
• Modify the assignment 3 static method (5) so that it will display only the drinkers information. The method will:
  • Have three parameters: the Drinker object
    the previously read height in inches
    the previously read weight in pounds
  • Use the Drinker object and a getter to display the drinker identifier
  • Display the Drinker's height in inches and weight in pounds (originally read from user)
  • Use the Drinker object and the getters to display the number of drinks consumed and the elapsed time while drinking.
    
    Sample of Output from this method

    Calculations for Drinker XYZ2345,
    who is 66 inches tall and weighs 150 pounds.
    
    After drinking 6 drinks, in 3 hours:

• Modify the main method to perform the following tasks (modified from Java Assn 3):
  • Remove the constants for converting the height and weight, since they are now located in the setters (but keep the metabolic rate constants).
  • After displaying program description, create an object of the new Drinker class type.
  • Use descriptive prompts to read:
    the drinkers last name (you can assume there will be no spaces in the last name and that it will contain at least 3 letters).
    the drinkers phone number
  • Same as in assn 3, use descriptive prompts to read: height in inches and weight in pounds.
    Sample Input read from main method

    Enter the drinker's last name: Smith
    Enter the drinker's phone number: 222-222-2222
    Enter drinker's height (in inches): 70
    Enter the drinker's weight (in pounds): 180

  • Use the Drinker object and the setters to set the values for all of the data fields of the object:
    Be sure to pass any necessary parameters to the setters.
    Note that the setters for the number of drinks and time elapsed will prompt the user for input.
  • After setting all the data fields, display a couple of blank lines to separate input and output.
  • Using the Drinker object:
    Call the volume distribution calculation method for men (method 2) to compute the volume distribution for men and save the result returned.
    Call the volume distribution calculation method for women (method 3) to compute the volume distribution for women and save the result returned.
  • Call the static method to display the drinker's information.
  • Use the Drinker object to call the instance method to calculate and display the BAC twice:
    The first call should pass in “male” as the gender String, the volume distribution computed for men, and the metabolic rate for men.
    The second call should pass in “female” as the gender String, the volume distribution computed for women, and the metabolic rate for women.

The main method code should not directly calculate any results, nor display any drinker information or BAC information. All this should be done from within methods that are called by the main method.

Complete Sample Output

Calculations for Drinker SMI2222,
who is 70 inches tall and weighs 180 pounds.

After drinking 4 drinks, in 2 hours:
if male, current BAC is approximately 0.067
if female, current BAC is approximately 0.096