Java Programming

This assignment is built on top of lab 6

Add capability to handle Grade Book for different subjects (Chemistry and Computer Science).

We will assume a maximum of five assignments and up to 40 students.

Details will be provided in the classFrom

Lab 6 - You have a Printable interface - used by Student.

Steps for completing Lab 7 -

1. Create a new interface for Faculty to use:

package adapter;

public interface Createable {

public void createGradeBook(String fname);

public void printGradeBook();

}

2. Create a class called InstructorReport

package model;

public class InstructorReport {

private Student s[] = null;

private Statistics st = null;

public InstructorReport(Student [] s, Statistics st){

this.s = s;

this.st = st

}

public void print() {

//call a method that prints info for all students - prints student []

//st.print();

}

}

3. Add methods in Util or FileIO class (Util package) to serialize and deserialize InstructorReport.

public void writetodisk(InstructorReport a1, String fname)

{

try {

FileOutputStream p = new FileOutputStream(fname);

ObjectOutputStream p1 = new ObjectOutputStream(p);

p1.writeObject(a1);

}

catch(Exception e)

{

//exception message

}

}

public InstructorReport readfromdiskforInstructor(String fname)

{

InstructorReport a= null;

try {

FileInputStream p = new FileInputStream(fname);

ObjectInputStream p1 = new ObjectInputStream(p);

a = (InstructorReport)p1.readObject();

}

catch(Exception e)

{

//exception message

}

return a;

}

4. Rename your Print class to CreatePrint.

package adapter;

public abstract class CreatePrint {

private Util u = new Util();

private Student arr[] = new Student[40];

private Statistics s = new Statistics();

private StudentReport arr2[] = new StudentReport[40];

private InstructorReport arr3 = null;

public void createGradeBook(String fname) {

//This method must be called first - before printGradeBook() or getStats() or printStudentScores()

//we will call existing methods to:

//a. read the file and build a student array - call readFile in Util

//b. compute statistics. - call methods in Statistics

//c. build StudentReport array [done in lab 6]

//d. serialize studentreport - upto 40 files. [done in lab 6]

//e. For instructor - write one file (serialized) with Student [] and Statistics[]

}

public void printGradeBook() { }

//use debug flag for printing. if debug = true then print other no printing.

public void getStats() {

//print stats from any object - read one object from disk and print stats.

}

public void printstudentscores(int id) {

//use the serialized life so your life is easy.

//pl. don't use search in studentreport array. long way. no good.

}

}

5. Create a class called GradeBook that extends the abstract class called CreatePrint

package adapter;

public class GradeBook extends CreatePrint implements Creatable, Printable {

}

//default package.

6. Testing your code

public class Driver7 {

public static void main(String [] args)

{

//Test Instructor interface

Creatable p = new GradeBook();

String fname = "c:\path to filename";

p.createGradeBook(fname);

p.printGradeBook();

//next three lines should give a compiler error - can you say why?

//p.getStats();

//p.printstudentscores(1234);

//p.printstudentscores(9111); //invalid student id shld print a friendly message - no such student.

//Test Student Interface

Printable s = p;

//s.printGradebook(); //Error

s.getStats();

s.printstudentscores(1234);

s.printstudentscores(9111); //invalid student id shld print a f

}

}

______________________________________________________________________________________________________

import model.StudentReport;

public class Driver

{

//create student report and process

public static void main(String[] args)

{

StudentReport report = new StudentReport();

report.process();

}

}

______________________________________________________________________________________________________

package model;

public class Statistics

{

// store lowest scores of students

private int[] lowScores;

// store highest scores of students

private int[] highScores;

// store averages of students

private double[] avgScores;

// store grades of students

private String[] grades;

//determines the lowest score and stores in an array

private void calcLowest(Student[] students)

{

// allocate memory

lowScores = new int[students.length];

// for each student

for (int i = 0; i < students.length; i++)

{

lowScores[i] = students[i].getLowest();

}

}

//determines the highest score and stores in an array

private void calcHighest(Student[] students)

{

// allocate memory

highScores = new int[students.length];

// for each student

for (int i = 0; i < students.length; i++)

{

highScores[i] = students[i].getHighest();

}

}

//computes average and grade of the students

private void calculateAverages(Student[] students)

{

// allocate memory

avgScores = new double[students.length];

grades = new String[students.length];

// for each student

for (int i = 0; i < students.length; i++)

{

// compute average

avgScores[i] = students[i].calcAverage();

// compute average

grades[i] = students[i].getGrade();

}

}

// print statistics for all students and all quizzes

public void printStatistics(Student[] students)

{

calcLowest(students);

calcHighest(students);

calculateAverages(students);

// Build header row

String output = "";

System.out.printf("******************************************************************** ");

output += String.format("*%-12s %-15s %-15s %-15s %s%n", "Student ID", "Highest Score", "Lowest Score",

"Average Score", "Grade* " + "********************************************************************");

for (int i = 0; i < students.length; i++)

{

output += String.format("%-12d %-15d %-15d %-15.2f %s%n", students[i].getSID(), highScores[i], lowScores[i],

avgScores[i], grades[i]);

}

System.out.printf(output);

}

}

______________________________________________________________________________________________________

package model;

import java.io.Serializable;

public class Student implements Serializable

{

private static final long serialVersionUID = -123433434343L;

private int SID;

private int scores[] = new int[5];

// getter and setter functions

public int getSID()

{

return this.SID;

}

// setter function

public void setSID(int id)

{

this.SID = id;

}

// Get scores

public int[] getScores()

{

return this.scores;

}

// set scores

public void setScores(int[] s)

{

// Make deep copy

for (int i = 0; i < s.length; i++)

{

this.scores[i] = s[i];

}

}

//determines highest score of a student

public int getHighest()

{

int highest = scores[0];

for (Integer i : scores)

{

if (i > highest)

{

highest = i;

}

}

return highest;

}

//determines lowest score of a student

public int getLowest()

{

int lowest = scores[0];

for (Integer i : scores)

{

if (i < lowest)

{

lowest = i;

}

}

return lowest;

}

//Determines the average score of a student

public double calcAverage()

{

double sum = 0;

for (Integer i : scores)

{

sum += i;

}

return sum / scores.length;

}

//determines the letter grade of the student by their average score

public String getGrade()

{

double average = calcAverage();

if (average >= 97)

return "A+";

else if (average >= 93)

return "A";

else if (average >= 90)

return "A-";

else if (average >= 87)

return "B+";

else if (average >= 83)

return "B";

else if (average >= 80)

return "B-";

else if (average >= 77)

return "C+";

else if (average >= 73)

return "C";

else if (average >= 70)

return "D+";

else if (average >= 63)

return "D";

else if (average >= 60)

return "D-";

else

return "F";

}

// prints all data of a student

public void printData()

{

System.out.printf("Student ID: " + SID + " ");

String str = "Scores: ";

for (int i = 0; i < scores.length; i++)

{

str += String.valueOf(scores[i]) + " ";

}

System.out.printf(str+" ");

System.out.printf("Lowest Score: " + getLowest()+" ");

System.out.printf("Highest Score: " + getHighest()+" ");

System.out.printf("Average Score: " + calcAverage()+" ");

System.out.printf("Letter Grade: " + getGrade()+" ");

}

}

_______________________________________________________________________________________________________

package model;

import adapter.Print;

import fileIO.Util;

public class StudentReport

{

//reads data, loads in an array, prints report

public void process()

{

// Load File

Student students[] = Util.readFile("Scores.txt");

// Serialize

Util.serializeStudents(students);

// Print Statistics

Print printer = new Print();

printer.printStats();

System.out.printf(" ******************************************* ");

System.out.printf("*Student Individual Reports by Student ID:* ");

System.out.printf("******************************************* ");

for(int i=0; i

{

System.out.printf("STUDENT #" + (i+1)+" ");

// print the student

printer.printStudentScores(students[i].getSID());

System.out.printf(" ");

}

}

}

_______________________________________________________________________________________________________

package fileIO;

import java.io.IOException;

import java.io.File;

import java.io.ObjectOutputStream;

import java.io.FileOutputStream;

import java.io.ObjectInputStream;

import java.io.FileInputStream;

import java.util.Scanner;

import model.Student;

public class Util

{

// binary file name

private static final String BINARY_FILE = "students.dat";

private static int numStudents;

//loads students into an array from the file

public static Student[] readFile(String fileName)

{

// Get student count

numStudents = countStudents(fileName);

// Create array to hold students, hold all students in file

Student students[] = new Student[numStudents];

try

{

File file = new File(fileName);

Scanner scanner = new Scanner(file);

// ignore first line

scanner.nextLine();

// Create Student records and store into array

for (int i = 0; i < numStudents; i++)

{

students[i] = new Student();

students[i].setSID(scanner.nextInt());

// read scores

int scores[] = new int[5];

for (int j = 0; j < 5; j++)

{

scores[j] = scanner.nextInt();

}

// set score

students[i].setScores(scores);

}

// close file

scanner.close();

}

catch (IOException e)

{

System.out.printf("Error -- " + e.toString());

}

return students;

}

//reads number of students in the file

private static int countStudents(String fileName)

{

int count = 0;

try

{

File file = new File(fileName);

Scanner scanner = new Scanner(file);

// ignore first line

scanner.nextLine();

// read line by line and count it

while (scanner.hasNextLine())

{

scanner.nextLine();

count++;

}

// close scanner

scanner.close();

}

catch (Exception e)

{

e.printStackTrace();

}

return count;

}

//serialize student data into a binary file

public static void serializeStudents(Student students[])

{

try

{

// open object output stream

File file = new File(BINARY_FILE);

FileOutputStream fos = new FileOutputStream(file);

ObjectOutputStream oos = new ObjectOutputStream(fos);

// write objects to file

for (Student std : students)

{

oos.writeObject(std);

}

// close stream

oos.close();

}

catch (Exception e)

{

e.printStackTrace();

}

}

//find student by ID in the binary file

public static Student getStudentByID(int id)

{

Student student = null;

try

{

// open object output stream

File file = new File(BINARY_FILE);

FileInputStream fis = new FileInputStream(file);

ObjectInputStream ois = new ObjectInputStream(fis);

Student std;

// read students

while ((std = (Student) ois.readObject()) != null)

{

if (std.getSID() == id)

{

student = std;

break;

}

}

// close stream

ois.close();

}

catch (Exception e)

{

e.printStackTrace();

}

return student;

}

//de-serialize students

public static Student[] getStudents()

{

Student students[] = new Student[numStudents];

try

{

// open object output stream

File file = new File(BINARY_FILE);

FileInputStream fis = new FileInputStream(file);

ObjectInputStream ois = new ObjectInputStream(fis);

Student std;

// read students

int counter = 0;

while (counter < numStudents && (std = (Student) ois.readObject()) != null)

{

students[counter++] = std;

}

// close stream

ois.close();

}

catch (Exception e)

{

e.printStackTrace();

}

return students;

}

}

_____________________________________________________________________________________________________

package adapter;

import model.Student;

import model.Statistics;

import fileIO.Util;

public class Print implements Printable

{

//Print Students statistics, read from the serialized file

public void printStats()

{

// Get all the Scores.

Student[] stds = Util.getStudents();

// Statistics object.

Statistics stats = new Statistics();

stats.printStatistics(stds);

}

//print statistics function by ID

public void printStudentScores(int id)

{

//Find Student by ID

Student std = Util.getStudentByID(id);

if(std == null)

{

System.out.printf("No Such Student exist with ID: " + id);

}

else

{

std.printData();

}

}

}

_______________________________________________________________________________________________________

package adapter;

public interface Printable

{

//Print Students statistics, read from the serialized file

public void printStats();

//print statistics function by ID

public void printStudentScores(int id);

}