Question

Set-Up ·

Create a new project in your Eclipse workspace named: Lab13 ·

In the src folder, create a package named: edu.ilstu ·

Import the following files from T:\it168\Labs\lab13. Note that the .txt file must be in the top level of your project, not inside your src folder. o Student.java

o StudentList.java

o students.txt

Carefully examine the Student.java and StudentList.java files. You are going to complete the StudentList class (updating all necessary Javadoc comments), following the instruction in the code.

Create a .java class called StudentListTester.java with a main method. In that class, write a program that tests all capabilities of the StudentList class. When writing the list to a file, use “studentout.txt”.

We have provided the students.txt file as an example data file.

The files need to be imported will be shown below

Student.java:

import java.io.PrintWriter;
import java.text.DecimalFormat;
import java.util.Scanner;

/**
* Student class maintains information about a particular student
*
* @author Mary Elaine Califf
*/
public class Student
{
private String name;
private String major;
private double gpa;
private int hoursCompleted;

/**Default constructor
*
*/
public Student()
{
       super();
   this.name = "";
   this.major = "";
   this.gpa = 0.0;
   this.hoursCompleted = 0;
}

/**Constructor
* @param name
* The student's name
* @param major
* The student's major
*/
public Student(String name, String major)
{
       super();
this.name = name;
this.major = major;
this.gpa = 0.0;
this.hoursCompleted = 0;
}

/**Constructor
* @param name
* The student's name
* @param major
* The student's major
* @param gpa
* The student's cumulative gpa
* @param hoursCompleted
* Number of credit hours the student has completed
*/
public Student(String name, String major, double gpa, int hoursCompleted)
{
       super();
this.name = name;
this.major = major;
this.gpa = gpa;
this.hoursCompleted = hoursCompleted;
}

/**
* @return The student's major.
*/
public String getMajor()
{
return this.major;
}
/**
* @param major The major to set.
*/
public void setMajor(String major)
{
this.major = major;
}
/**
* @return The student's name.
*/
public String getName()
{
return this.name;
}
/**
* @param name The name to set.
*/
public void setName(String name)
{
this.name = name;
}
/**
* @return The student's gpa.
*/
public double getGpa()
{
return this.gpa;
}
/**
* @return The number of credit hours the student has completed.
*/
public int getHoursCompleted()
{
return this.hoursCompleted;
}

/**
* @return The student's class (Freshman, Sophomore, Junior, Senior)
*/
public String getClassLevel()
{
String classLevel;
if (this.hoursCompleted < 30)
{
classLevel = "Freshman";
}
else if (this.hoursCompleted < 60)
{
classLevel = "Sophomore";
}
else if (this.hoursCompleted < 90)
{
classLevel = "Junior";
}
else
{
classLevel = "Senior";
}
return classLevel;
}

/**Update student's information to reflect completion of a semester's work
* @param semHours
* Number of credit hours the student has just completed
* @param semGPA
* GPA for the semester just completed
*/
public void updateStudent(int semHours, double semGPA)
{
int oldHours = this.hoursCompleted;
this.hoursCompleted = oldHours + semHours;
this.gpa = (oldHours * this.gpa + semHours * semGPA) / this.hoursCompleted;
}

/**Produces a string with information about a student in a nice format with
* appropriate labeling
*/
public String toString()
{
DecimalFormat fmt = new DecimalFormat("0.000");
String myString = this.name + " is a " + getClassLevel() + " "
   + this.major + "\n"
   + "who has completed " + this.hoursCompleted + " hours " +
   "with a " + fmt.format(this.gpa) + " gpa.\n";
return myString;
}

/** Reads student data in file format with name on first line, hours and gpa
* on second line, and major on third line.
* @param input
* Scanner connected to input source for student information
*/
public void read(Scanner input)
{
   this.name = input.nextLine();
   this.hoursCompleted = input.nextInt();
   this.gpa = input.nextDouble();
   input.nextLine();
   this.major = input.nextLine();
}

/**
* Prints student information in file format
* @param output
* PrintWriter connected to open output stream
*/
public void write(PrintWriter output)
{
   output.println(this.name);
   output.println(this.hoursCompleted + " " + this.gpa);
   output.println(this.major);
}
}

StudentList.java:

import java.io.*;

/**
* A class to maintain an array of students
*/
public class StudentList
{
   // add appropriate instance variables here: need an array of Students
   // and a way to keep track of how many students are in the list
   // assume there will never be more than 100 students
   // call your array stuArray

   // provide a default constructor that sets up an empty student array

   // provide a private helper method that accepts a Student's name and
   //   returns the index of the student in the array or -1 if the student
   //   is not in the array. This method should be called by the
   //   displayStudent method

   /**Reads a list of students from a file
   * @param fileName
   * Name of the file to read from
   */
   public void readList(String fileName)
   {
       // fill in code to read a list of students from a file
       // into the array -- this should end with StudentList
       // consisting of exactly those students in the file--so
       // the first student in the file will be the first student
       // in the array, and all operations on the list will only
       // affect the set of students in the file until additional
       // students are added using the addStudent method below.
       // Make sure you don't overfill the array.
       // For each student, create the Student object using the default
       // constructor and then use the read method of Student to get
       // the data from the file
   }

   /** Writes a list of students to a file
   * @param fileName
   * Name of the file to write to
   */
   public void writeList(String fileName)
   {
       PrintWriter outfile = null;
       try
       {
           outfile = new PrintWriter(new FileWriter("output.txt"));
           // use a for loop to write all of the Student objects from
           // the array to output.txt by calling the Student's write
           // method and passing it outfile
          
           outfile.close();
       }
       catch (IOException e)
       {
           System.out.println("An error occurred: "+e);
           System.out.println("The list of students was not written");
       }
   }

   /** Add a student to the end of the list
   * @param aStudent
   * The student to add
   */
   public void addStudent(Student aStudent)
   {
       // write code to add a student to the end of the list of students only if there is room
   }

   /**
   * @param studentName
   */
   public void displayStudent(String studentName)
   {
       // fill in missing pieces of the following code and uncomment it
       // add appropriate code to handle an incorrect name
       /*
       int index;
       index = // fill in code here ;
       System.out.println(this.stuArray[index]);
       */
   }

   // Write a method to count the number of freshmen, sophomores, juniors and seniors in the array
   // and print the counts to the screen. The Student class has a getClassLevel method that
   // returns a String with the value "Freshman", "Sophomore", "Junior" or "Senior". Use an array
   // to store your counts.
   // add an appropriate javadoc comment
   public void printClassCounts()
   {

   }
}

students.txt

Ann Hawkins
16 3.6
English
Miles Kimball
33 3.8
Computer Science
Mary Ellen de Silva
94 2.97
Arts Technology

Answer 1

Note: Could you plz go through this code and let me know if u need any changes in this.Thank You
_________________

students.txt (input file)

Ann Hawkins
16 3.6
English
Miles Kimball
33 3.8
Computer Science
Mary Ellen de Silva
94 2.97
Arts Technology

_________________________

// Student.java

package edu.ilstu;

import java.io.PrintWriter;
import java.text.DecimalFormat;
import java.util.Scanner;

/**
* Student class maintains information about a particular student
*
* @author Mary Elaine Califf
*/
public class Student {
   private String name;
   private String major;
   private double gpa;
   private int hoursCompleted;

   /**
   * Default constructor
   *
   */
   public Student() {
       super();
       this.name = "";
       this.major = "";
       this.gpa = 0.0;
       this.hoursCompleted = 0;
   }

   /**
   * Constructor
   *
   * @param name
   * The student's name
   * @param major
   * The student's major
   */
   public Student(String name, String major) {
       super();
       this.name = name;
       this.major = major;
       this.gpa = 0.0;
       this.hoursCompleted = 0;
   }

   /**
   * Constructor
   *
   * @param name
   * The student's name
   * @param major
   * The student's major
   * @param gpa
   * The student's cumulative gpa
   * @param hoursCompleted
   * Number of credit hours the student has completed
   */
   public Student(String name, String major, double gpa, int hoursCompleted) {
       super();
       this.name = name;
       this.major = major;
       this.gpa = gpa;
       this.hoursCompleted = hoursCompleted;
   }

   /**
   * @return The student's major.
   */
   public String getMajor() {
       return this.major;
   }

   /**
   * @param major
   * The major to set.
   */
   public void setMajor(String major) {
       this.major = major;
   }

   /**
   * @return The student's name.
   */
   public String getName() {
       return this.name;
   }

   /**
   * @param name
   * The name to set.
   */
   public void setName(String name) {
       this.name = name;
   }

   /**
   * @return The student's gpa.
   */
   public double getGpa() {
       return this.gpa;
   }

   /**
   * @return The number of credit hours the student has completed.
   */
   public int getHoursCompleted() {
       return this.hoursCompleted;
   }

   /**
   * @return The student's class (Freshman, Sophomore, Junior, Senior)
   */
   public String getClassLevel() {
       String classLevel;
       if (this.hoursCompleted < 30) {
           classLevel = "Freshman";
       } else if (this.hoursCompleted < 60) {
           classLevel = "Sophomore";
       } else if (this.hoursCompleted < 90) {
           classLevel = "Junior";
       } else {
           classLevel = "Senior";
       }
       return classLevel;
   }

   /**
   * Update student's information to reflect completion of a semester's work
   *
   * @param semHours
   * Number of credit hours the student has just completed
   * @param semGPA
   * GPA for the semester just completed
   */
   public void updateStudent(int semHours, double semGPA) {
       int oldHours = this.hoursCompleted;
       this.hoursCompleted = oldHours + semHours;
       this.gpa = (oldHours * this.gpa + semHours * semGPA)
               / this.hoursCompleted;
   }

   /**
   * Produces a string with information about a student in a nice format with
   * appropriate labeling
   */
   public String toString() {
       DecimalFormat fmt = new DecimalFormat("0.000");
       String myString = this.name + " is a " + getClassLevel() + " "
               + this.major + "\n" + "who has completed "
               + this.hoursCompleted + " hours " + "with a "
               + fmt.format(this.gpa) + " gpa.\n";
       return myString;
   }

   /**
   * Reads student data in file format with name on first line, hours and gpa
   * on second line, and major on third line.
   *
   * @param input
   * Scanner connected to input source for student information
   */
   public void read(Scanner input) {
       this.name = input.nextLine();
       this.hoursCompleted = input.nextInt();
       this.gpa = input.nextDouble();
       input.nextLine();
       this.major = input.nextLine();
   }

   /**
   * Prints student information in file format
   *
   * @param output
   * PrintWriter connected to open output stream
   */
   public void write(PrintWriter output) {
       output.println(this.name);
       output.println(this.hoursCompleted + " " + this.gpa);
       output.println(this.major);
   }
}

_________________________

// StudentList.java

package edu.ilstu;

import java.io.*;
import java.util.Scanner;

/**
* A class to maintain an array of students
*/
public class

package edu.ilstu;

import java.io.*;
import java.util.Scanner;

/**
* A class to maintain an array of students
*/
public class StudentList
{
// add appropriate instance variables here: need an array of Students
// and a way to keep track of how many students are in the list
// assume there will never be more than 100 students
// call your array stuArray

private Student stdArray[]=null;
private int counter;
// provide a default constructor that sets up an empty student array
public StudentList() {
stdArray=new Student[100];
counter=0;
}

// provide a private helper method that accepts a Student's name and
// returns the index of the student in the array or -1 if the student
// is not in the array. This method should be called by the
// displayStudent method
public int getStudentIndx(String name)
{
   int indx=-1;
   for(int i=0;i<counter;i++)
   {
       if(stdArray[i].getName().equalsIgnoreCase(name))
           indx=i;
   }
   return indx;
}

/**Reads a list of students from a file
* @param fileName
* Name of the file to read from
*/
public void readList(String fileName)
{
// fill in code to read a list of students from a file
// into the array -- this should end with StudentList
// consisting of exactly those students in the file--so
// the first student in the file will be the first student
// in the array, and all operations on the list will only
// affect the set of students in the file until additional
// students are added using the addStudent method below.
// Make sure you don't overfill the array.
// For each student, create the Student object using the default
// constructor and then use the read method of Student to get
// the data from the file
   Scanner sc=null;
   String name,major,str;
   int hours;
   double gpa;
   try {
       sc=new Scanner(new File(fileName));
       while(sc.hasNext())
       {
  
       if(stdArray.length!=counter)
       {
           name=sc.nextLine();
           str=sc.nextLine();
           String arr[]=str.split(" ");
           hours=Integer.parseInt(arr[0]);
           gpa=Double.parseDouble(arr[1]);
           major=sc.nextLine();
          
           Student s=new Student(name, major, gpa, hours);      
           addStudent(s);
       }
       }
   } catch (FileNotFoundException e) {
       System.out.print("** File not found **");
   }
}

/** Writes a list of students to a file
* @param fileName
* Name of the file to write to
*/
public void writeList(String fileName)
{
PrintWriter outfile = null;
try
{
outfile = new PrintWriter(new FileWriter(fileName));
// use a for loop to write all of the Student objects from
// the array to output.txt by calling the Student's write
// method and passing it outfile
for(int i=0;i<counter;i++)
{
   stdArray[i].write(outfile);
}
  
outfile.close();
}
catch (IOException e)
{
System.out.println("An error occurred: "+e);
System.out.println("The list of students was not written");
}
}

/** Add a student to the end of the list
* @param aStudent
* The student to add
*/
public void addStudent(Student aStudent)
{
// write code to add a student to the end of the list of students only if there is room
   stdArray[counter]=aStudent;
       counter++;
}

/**
* @param studentName
*/
public void displayStudent(String studentName)
{
// fill in missing pieces of the following code and uncomment it
// add appropriate code to handle an incorrect name

int index;
index =getStudentIndx(studentName);
if(index==-1)
{
   System.out.println("Student Not Found");
}
else
{
   System.out.println(stdArray[index]);
}
         

}

// Write a method to count the number of freshmen, sophomores, juniors and seniors in the array
// and print the counts to the screen. The Student class has a getClassLevel method that
// returns a String with the value "Freshman", "Sophomore", "Junior" or "Senior". Use an array
// to store your counts.
// add an appropriate javadoc comment
public void printClassCounts()
{
// int cntFreshMan=0,cntSophomore=0,cntJunior=0,cntSenior=0;
int cnts[]=new int[4];
for(int i=0;i<counter;i++)
{
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Freshman"))
   {
       cnts[0]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Sophomore"))
   {
       cnts[1]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Junior"))
   {
       cnts[2]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Senior"))
   {
       cnts[3]++;
   }
     
     
     
}

System.out.println("No of Freshman :"+cnts[0]);
System.out.println("No of Sophomore :"+cnts[1]);
System.out.println("No of Junior :"+cnts[2]);
System.out.println("No of Senior :"+cnts[3]);


}
}

{
// add appropriate instance variables here: need an array of Students
// and a way to keep track of how many students are in the list
// assume there will never be more than 100 students
// call your array stuArray

private Student stdArray[]=null;
private int counter;
// provide a default constructor that sets up an empty student array
public StudentList() {
stdArray=new Student[100];
counter=0;
}

// provide a private helper method that accepts a Student's name and
// returns the index of the student in the array or -1 if the student
// is not in the array. This method should be called by the
// displayStudent method
public int getStudentIndx(String name)
{
   int indx=-1;
   for(int i=0;i<counter;i++)
   {
       if(stdArray[i].getName().equalsIgnoreCase(name))
           indx=i;
   }
   return indx;
}

/**Reads a list of students from a file
* @param fileName
* Name of the file to read from
*/
public void readList(String fileName)
{
// fill in code to read a list of students from a file
// into the array -- this should end with StudentList
// consisting of exactly those students in the file--so
// the first student in the file will be the first student
// in the array, and all operations on the list will only
// affect the set of students in the file until additional
// students are added using the addStudent method below.
// Make sure you don't overfill the array.
// For each student, create the Student object using the default
// constructor and then use the read method of Student to get
// the data from the file
   Scanner sc=null;
   String name,major,str;
   int hours;
   double gpa;
   try {
       sc=new Scanner(new File(fileName));
       while(sc.hasNext())
       {
  
       if(stdArray.length!=counter)
       {
           name=sc.nextLine();
           str=sc.nextLine();
           String arr[]=str.split(" ");
           hours=Integer.parseInt(arr[0]);
           gpa=Double.parseDouble(arr[1]);
           major=sc.nextLine();
          
           Student s=new Student(name, major, gpa, hours);      
           addStudent(s);
       }
       }
   } catch (FileNotFoundException e) {
       System.out.print("** File not found **");
   }
}

/** Writes a list of students to a file
* @param fileName
* Name of the file to write to
*/
public void writeList(String fileName)
{
PrintWriter outfile = null;
try
{
outfile = new PrintWriter(new FileWriter(fileName));
// use a for loop to write all of the Student objects from
// the array to output.txt by calling the Student's write
// method and passing it outfile
for(int i=0;i<counter;i++)
{
   stdArray[i].write(outfile);
}
  
outfile.close();
}
catch (IOException e)
{
System.out.println("An error occurred: "+e);
System.out.println("The list of students was not written");
}
}

/** Add a student to the end of the list
* @param aStudent
* The student to add
*/
public void addStudent(Student aStudent)
{
// write code to add a student to the end of the list of students only if there is room
   stdArray[counter]=aStudent;
       counter++;
}

/**
* @param studentName
*/
public void displayStudent(String studentName)
{
// fill in missing pieces of the following code and uncomment it
// add appropriate code to handle an incorrect name

int index;
index =getStudentIndx(studentName);
if(index==-1)
{
   System.out.println("Student Not Found");
}
else
{
   System.out.println(stdArray[index]);
}
         

}

// Write a method to count the number of freshmen, sophomores, juniors and seniors in the array
// and print the counts to the screen. The Student class has a getClassLevel method that
// returns a String with the value "Freshman", "Sophomore", "Junior" or "Senior". Use an array
// to store your counts.
// add an appropriate javadoc comment
public void printClassCounts()
{
// int cntFreshMan=0,cntSophomore=0,cntJunior=0,cntSenior=0;
int cnts[]=new int[4];
for(int i=0;i<counter;i++)
{
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Freshman"))
   {
       cnts[0]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Sophomore"))
   {
       cnts[1]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Junior"))
   {
       cnts[2]++;
   }
   if(stdArray[i].getClassLevel().equalsIgnoreCase("Senior"))
   {
       cnts[3]++;
   }
     
     
     
}

System.out.println("No of Freshman :"+cnts[0]);
System.out.println("No of Sophomore :"+cnts[1]);
System.out.println("No of Junior :"+cnts[2]);
System.out.println("No of Senior :"+cnts[3]);


}
}

_____________________________

// StudentListTester.java

package edu.ilstu;

import java.util.Scanner;

public class StudentListTester {

   public static void main(String[] args) {
       /*
       * Creating an Scanner class object which is used to get the inputs
       * entered by the user
       */
       Scanner sc = new Scanner(System.in);
       Student stdArr[]=new Student[3];
       for(int i=0;i<stdArr.length;i++)
       {
           stdArr[i]=new Student();
       }
       for(int i=0;i<stdArr.length;i++)
       {
           System.out.println("Enter Student#"+(i+1)+" Data :");
           stdArr[i].read(sc);
       }
       StudentList sl=new StudentList();
       for(int i=0;i<stdArr.length;i++)
       {
           sl.addStudent(stdArr[i]);
       }
      
       stdArr[0].updateStudent(14,3.9);
       System.out.println("Tony is found at index :"+sl.getStudentIndx("Tony"));
       System.out.println("\"Tony\" Student Info :");
       sl.displayStudent("Tony");
       System.out.println();
       sl.readList("students.txt");
      
       sl.writeList("output.txt");
       sl.printClassCounts();

   }

}

_________________________

Output( console):

Enter Student#1 Data :
Kane Williams
12
3.5
Computer Science
Enter Student#2 Data :
Bean Johnson
8
3.2
Electronics
Enter Student#3 Data :
Tony
5
3.7
Mechanical
Tony is found at index :2
"Tony" Student Info :
Tony is a Freshman Mechanical
who has completed 5 hours with a 3.700 gpa.

No of Freshman :4
No of Sophomore :1
No of Junior :0
No of Senior :1

________________________

// output.txt (output file)

Kane Williams
26 3.715384615384615
Computer Science
Bean Johnson
8 3.2
Electronics
Tony
5 3.7
Mechanical
Ann Hawkins
16 3.6
English
Miles Kimball
33 3.8
Computer Science
Mary Ellen de Silva
94 2.97
Arts Technology

_______________Could you plz rate me well.Thank You