This exercise asks you to to develop a GradeSummary class that takes multiple instances of StudentResult and produce a summary of how many students achieved each grade (HD, D, C, etc) and who the top scoring student was.

For this exercise your GradeSummary class will be tested directly. The Runner class is not involved in testing at all, and any changes you make to it will be ignored. Feel free to edit it to isolate and test different parts of your code.

Specification

Your GradeSummary class must provide the following methods:

A constructor that accepts no input. Calling this constructor should result in a new instance of GradeSummary being created that is empty (i.e. does not include any student results).

An add method that accepts an instance of StudentResult as input, and returns nothing. Calling this method should cause the summary to be updated to include the given student result.

An addAll method that accepts an array of StudentResult as input, and returns nothing. Calling this method should cause the summary to be updated to include all of the given student results.

A reset method that accepts no input, and returns nothing. Calling this method should cause all data in the summary to be completely reset (i.e. so that it does not include any student results).

A renderToString method that accepts no input, and returns a String containing a rendered summary of student results. If the summary is empty (i.e. if it has just been created or just been reset), then this method should return "No results to show" without any punctuation. If at least one student result has been added then it should return a summary of how many students achieved each grade (HD, D, C, etc) and who the top scoring student was (see example section below).

All of these methods should be public and not static. There should not be any other public methods or properties, but you are welcome to add any private properties and methods that you feel are necessary/helpful.

Available classes and methods

To assist you in this task, your workspace includes precompiled versions of Student, Subject and StudentSummary, all of which have been implemented according to the specification defined in the previous task (Storing student results). You can use them here even if you didn't successfully complete the previous task.

Your workspace also incudes a precompiled PercentFormatter class, which provides the following methods:

A static format method that accepts a decimal number (as a double) as input, and returns a String containing the number formatted as a percentage value. For example, if given the number 25 as input, this method will return the string "25.0%".

A static format method that accepts a dividend (as an int) and a divisor (as an int), and returns a String containing the result of dividing the dividend by the divisor, formatted as a percentage value .For example, if given the dividend 1 and the divisor 3, this method will return the string "33.3%".

Finally, we have also provided the following helper properties/methods within the GradeSummary class:

A static grades property that contains a list of available grades (as a String array) in descending order: e.g. HD, D, C, etc.

A static getGradeIndex method that accepts a grade (as a String) and returns the index of that grade in the grades array (as an int). For example if given the grade "HD", this method will return 0. If given the grade "D" this method will return 1.

Example

Here is what the output of your program should look like if you implement GradeSummary correctly and leave the runner unchanged:

Note that these results are completely fictional, and have been generated randomly.

Results for Programming Fundamentals HD: 12 (19.4%) D: 6 (9.7%) C: 4 (6.5%) P: 12 (19.4%) Z: 28 (45.2%) Top student: 2532375: Maximilian Owens with 96.7% (HD) Results for Communication for IT Professionals HD: 12 (19.7%) D: 3 (4.9%) C: 4 (6.6%) P: 7 (11.5%) Z: 35 (57.4%) Top student: 2570704: Rebecca Holmes with 100.0% (HD) Results for Introduction to Information Systems HD: 10 (13.0%) D: 9 (11.7%) C: 3 (3.9%) P: 14 (18.2%) Z: 41 (53.2%) Top student: 2420256: Michael Riley with 97.4% (HD)

Your code will be tested with different data (i.e. different student results) so you can't pass the tests just by printing out this summary verbatim.

Runner.java:

public class Runner {

public static void main(String[] args) throws Exception {

StudentResult[] allResults = ResultLoader.readFile("results.csv");

//Create summaries for each subject String[] subjects = { "Programming Fundamentals", "Communication for IT Professionals", "Introduction to Information Systems" };

GradeSummary[] subjectSummaries = new GradeSummary[subjects.length]; for (int i=0 ; i

//Go through each result, adding it to the appropriate summary for (StudentResult result: allResults) {

//add result to appropriate subject summary for (int i=0 ; i

//if the current result is for the current subject if (result.getSubject().getName().equals(subjects[i])) { //add it to the corresponding summary subjectSummaries[i].add(result); } } } //print summaries for (int i=0 ; i< subjects.length ; i++) { System.out.println("Results for " + subjects[i]); System.out.println(subjectSummaries[i].renderToString()); } } }

GradeSumamry.java:

public class GradeSummary {

private static String[] grades = {"HD", "D", "C", "P", "Z"} ;

private static int getGradeIndex(String grade) { switch (grade) { case "HD": return 0; case "D": return 1 ; case "C": return 2 ; case "P": return 3 ; case "Z": return 4 ; }

return -1 ; }

//Implement the rest of GradeSummary here

}