Java Dossier, Piano Student Database. Main help!?

[Peril]

I'm having trouble writing a main for my database. Basically the database I have is a database for piano teachers to keep track of their students. I'll attach the code. Can anyone help me with the main? Thanks. I will include all the sections of the code. There are 7.

Below is the Student Class

public class Student 
{
	// attributes
	private String firstName = " ";	
	private String lastName = " ";	
	private int musicLevel = 0;	
	private CompetitionLinkedList competitions = null;		
	private String futureGoals = " ";
	

// default constructor - initializes default attr values
	public Student() 
   	{
   	}

// specific constructor
	public Student(String newFirstName, String newLastName, 
		int newMusicLevel, CompetitionLinkedList newCompetitions, String newFutureGoals)
	{
	   	firstName = newFirstName;
		lastName = newLastName;
		musicLevel= newMusicLevel;		
		competitions = newCompetitions;		
		futureGoals = newFutureGoals;
	}

    // setters (mutators)
	public void setFirstName(String newFirstName)
		{
			firstName = newFirstName;
		}
	public void setLastName(String newLastName)
		{
			lastName = newLastName;
		}
	public void setMusicLevel(int newMusicLevel)
		{
			musicLevel = newMusicLevel;
		}
	public void setCompetitions (CompetitionLinkedList newCompetitions) 
		{
			competitions = newCompetitions;
		}
	public void setFutureGoals (String newFutureGoals)
		{
			futureGoals = newFutureGoals;
		}
    // getters (accessors)
	public String getFirstName()
		{
			return firstName;
		}
	public String getLastName()
		{
			return lastName;
		}
	public int getMusicLevel()
		{
			return musicLevel;
		}
	public CompetitionLinkedList getCompetitions()
		{
			return competitions;
		}
	public String getFutureGoals()
		{
			return futureGoals;
		}

}

Below is the Student Node

public class StudentNode
{
	public Student myStudent = null;
	public StudentNode next = null;
	
	//default constructor
	public StudentNode()
	{
		
	}
}

Below is the Student Linked List

public class StudentLinkedList
{
	// attributes
	private StudentNode head = null;
	private StudentNode tail = null;
	private int size = 0;

	// default constructor
	public StudentLinkedList()
	{
	}
	
	// isEmpty() returns true if the LinkedList is empty, and false otherwise
	public boolean isEmpty()
	{
		return size == 0;
		//return head == null;
	}
		
	public boolean add(Student newStudent)
	{
		//1st case - adding to empty LL
		if (isEmpty())
		{
			StudentNode myStudentNode = 
				new StudentNode();
			myStudentNode.myStudent = newStudent;
			head = myStudentNode;
			tail = myStudentNode;
			size ++;
		}
		//2nd case - adding to non-empty LL
		else if (!isEmpty())
		{
			StudentNode myStudentNode = 
				new StudentNode();
			myStudentNode.myStudent = newStudent;
			tail.next = myStudentNode;
			tail = myStudentNode;
			size ++;
		}
		else
		{
			return false; 
		}
	}
	public Student remove(int index)
	{
		//0) removing from index out of bounds
		if (index >= size || index < 0)
		{
			return null;
		}
		
		//1) remove from empty LL - return error code
		if (isEmpty())
		{
			return null;
		}
		
		//2) remove last StudentNode from LL
		if (index == 0 && head == tail)	// if (size == 1)
		{
			Student tmp = head.myStudent;
			head = null;
			tail = null;
			size--;
			return tmp;
		}
		
		//3) remove from the middle (b/w head and tail) of the LL
		if (index != 0 && index != size -1)
		{
			int count = 0;
			StudentNode previous = head;
			for (StudentNode current = head; 
				current != null; current = current.next)
			{
				//if you are at the correct current, set t
				//he previous next to the current's next
				if (count == index)
				{
					Student x = current.myStudent;
					previous.next = current.next;
					size--;
					return null;
				}
				
				previous = current;
				count++;
			}
		}
		
		//4) remove from the head
		if (index == 0 && head != tail)
		{
			Student tmp = head.myStudent;
			head = head.next;
			return null;
		}
		
		//5) remove from the tail
		if ( index == size - 1 && size > 1)
		{
			Student tmp = tail.myStudent;
			
			for (StudentNode current = head; current != null; 
				current = current.next)
			{
				if (current.next == tail)
				{
					tail = current;
					tail.next = null; //current.next = null;
					size--;
					return tmp;
				}
			}
			return tmp;
		}
		else
		{
			return null;
		}
	}
		
		//add num to the location index WHY DO I HAVE THIS?
	public void add(int num, int index)
	{
			//0) adding to empty LL
//		if (isEmpty())
//		{
//			StudentNode myStudentNode = new StudentNode();
//			myStudentNode.myStudent = num;
//			head = myStudentNode;
//			tail = myStudentNode;
//			size ++;
//		}
			//1) adding to the head (beginning)
		
		if (!isEmpty() && index == 0) 
		{
			StudentNode myStudentNode = new StudentNode();
			myStudentNode.myStudent = null;
			tail.next = myStudentNode;
			tail = myStudentNode;
			size ++;
		}

		if (!isEmpty() && index == size) 
		{
			StudentNode myStudentNode = new StudentNode();
			myStudentNode.myStudent = null;
			head.next = myStudentNode;
			tail = myStudentNode;
			size ++;
		}
	}
	
		//print() traverses the linked list and prints out the numbers in each Node
		//CREATE print() METHOD HERE
	public void print()
	{
		for(StudentNode currentNode = head; currentNode != null; currentNode = currentNode.next)
		{
			System.out.print(currentNode.myStudent + " ");
		}
			
	}


}

Below is the Competition Class

public class Competition
{	
	private String competitionName = " ";
	private int score = 0;
	
	public Competition()
	{
	}
	//specific instructor
	public Competition(String newCompetitionName, int newScore)
	{
		competitionName = newCompetitionName;
		score = newScore;
	}

	//setters
	public void setcompetitionName(String newcompetitionName)
	{
		competitionName = newcompetitionName;
	}
	public void setScore(int newScore)
	{
		score = newScore;
	}

	//getters
	public String getcompetitionName()
	{
		return competitionName;
	}
	public int getScore()
	{
		return score;
	}
}

Below is the Competition Node

public class CompetitionNode
{
	public Competition c = null;
	public CompetitionNode next = null;
	
	//default constructor
	public CompetitionNode()
	{
		
	}
}

Below is the Competition Linked List Class

public class CompetitionLinkedList
{
	// attributes
	private CompetitionNode head = null;
	private CompetitionNode tail = null;
	private int size = 0;

	// default constructor
	public CompetitionLinkedList()
	{
	}
	
	// isEmpty() returns true if the LinkedList is empty, and false otherwise
	public boolean isEmpty()
	{
		return size == 0;
		//return head == null;
	}
		
	public void add(Competition newCompetition)
	{
		//1st case - adding to empty LL
		if (isEmpty())
		{
			CompetitionNode myNode = new CompetitionNode();
			myNode.c = newCompetition;
			head = myNode;
			tail = myNode;
			size ++;
		}
		//2nd case - adding to non-empty LL
		else if (!isEmpty())
		{
			CompetitionNode myNode = new CompetitionNode();
			myNode.c = newCompetition;
			tail.next = myNode;
			tail = myNode;
			size ++;
		}	
	}
	// THIS DOESNT WORK! PUBLIC COMPETITION DOESNT WORK WITH AN INT
	public Competition remove(int index)
	{
		//0) removing from index out of bounds
		if (index >= size || index < 0)
		{
			return null;
		}
		
		//1) remove from empty LL - return error code
		if (isEmpty())
		{
			return null;
		}
		
		//2) remove last Node from LL
		if (index == 0 && head == tail)	// if (size == 1)
		{
			Competition temp = head.c; // here because the node says competition is c.
			head = null;
			tail = null;
			size--;
			return temp;
		}
		
		//3) remove from the middle (b/w head and tail) of the LL
		if (index != 0 && index != size -1)
		{
			
			int count = 0;
			CompetitionNode previous = head;
			for (CompetitionNode current = head; current != null; current = current.next)
			{
				//if you are at the correct current, set the previous next to the current's next
				if (count == index)
				{
					Competition x = current.c;
					previous.next = current.next;
					size--;
					return x;
				}
				
				previous = current;
				count++;
			}
		}
		
		//4) remove from the head
		if (index == 0 && head != tail)
		{
			Competition tmp = head.c;
			head = head.next;
			return tmp;
		}
		
		//5) remove from the tail
		if ( index == size - 1 && size > 1)
		{
			Competition tmp = tail.c;
			
			for (CompetitionNode current = head; current != null; current = current.next)
			{
				if (current.next == tail)
				{
					tail = current;
					tail.next = null;	//current.next = null;
					size--;
					return tmp;
				}
			}
			return tmp;
		}
		return null;
	}
		
		//add num to the location index
	public void add(int num, int index)
	{
		//0) adding to empty LL
		if (isEmpty())
		{
			CompetitionNode temp = new CompetitionNode();
			temp.c = null;
			head = temp;
			tail = temp;
			size ++;
		}
		//1) adding to the head (beginning)
		if (!isEmpty() && index == 0 )
		{
			CompetitionNode temp = new CompetitionNode();
			temp.c = null;
			temp.next = head;
			head = temp;
			size ++;
		}
		//2) adding to the tail (end)
		if (!isEmpty() && index == size)
		{
			CompetitionNode temp = new CompetitionNode();
			temp.c = null;
			tail.next = temp;
			tail = temp;
			size ++;
		}
		//3) adding to the middle
		if (!isEmpty() && index < size && index > 0)
		{
			int count = 0;
			CompetitionNode previous = head;
			for(CompetitionNode current = head; current != null; current = current.next)
			{
				if (count == index)
				{
					CompetitionNode temp = new CompetitionNode();
					temp.c = null;
					temp.next = current;
					previous.next = temp;
				}
				previous = current;
				count ++;
			}
			size ++;
		}
		//4) adding to an index that is out of bounds
		if (!isEmpty() && index > size)
		{
			System.out.println("Error. Index is out of the range.");
		}
	}
	
	//getNum(int index) returns the number found in the Node at the specified index
	//CREATE getNum() METHOD HERE
	
	public Competition getCompetition(int index)
	{
		int count = 0;
		//int tmp = CompetitionLinkedList.find; // For returning a index?
		for(CompetitionNode current = head; current != null; current = current.next)
		{
			if (count == index)
			{
				return current.c;
			}
			count ++;
		}
		return null;
	}
	//print() traverses the linked list and prints out the numbers in each Node
	//CREATE print() METHOD HERE
	public void print()
	{
		for(CompetitionNode currentNode = head; currentNode != null; currentNode = currentNode.next)
		{
			System.out.print(currentNode.c + " ");
		}
	}

}

And finally, my main.

import java.io.*;
public class pianoStudentDatabaseMain
{

	private static BufferedReader stdin = 
	    new BufferedReader( new InputStreamReader( System.in ) );

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

		pianoStudentDatabaseMain database = new pianoStudentDatabaseMain();
		System.out.println("Welcome to the Piano Student Database.");
		while(true)
		{
			
			
			System.out.println("(main menu)");
			String input = stdin.readLine();
			
			System.out.println("\n" + "Select (S) to search for a student, give first name");
			System.out.println("\n" + "Select (A) to add a new student");
			System.out.println("\n" + "Select (E) to edit an existing student");
			System.out.println("\n" + "Select (Q) to quit");
			
			if (input.equals("S"))
			{
				// SEARCH GOES HERE
			}
			else if (input.equals("A"))
			{	
				Student newStudent = new Student();				

				System.out.print( "Input first name: ");
				input = stdin.readLine();
				newStudent.setFirstName(input);		
				
				System.out.print( "Input last name: ");
				input = stdin.readLine();
				newStudent.setLastName(input);	
				
						
				System.out.print( "Input music level: ");
				input = stdin.readLine();
				newStudent.setMusicLevel(Integer.parseInt(input));
						
				
				System.out.print( "Input future goals for the selected student: ");
				input = stdin.readLine();
				newStudent.setFutureGoals(input);
				
				book.addStudent(newStudent);
						
			
			}
			else if (input.equals("E"))
			{
				
			}

			else if (input.equals("Q"))
			{
				System.out.println("You have quit the Piano Student Database.");
				break;
			}

			else if (input.equals("S"))
			{
				book.selectionSort();
				System.out.println("Selection list: ");
				book.print();
			}
			
			
			
			else
			{
				System.out.println("Error, inccorect input.");
			}
		}
	
	}
}

[Peril]

I've since gone back and fixed all the errors. Still can't make the main though...

[RamyaSivakanth]

Hi,
Please don't expect the people to fix even the compilation errors.

I just given a look at ur code.where u have declared the book?

For add method where u have returned?