// imports
import java.io.*;		// Input stream
import java.util.*;		// Date
//import java.text.*; 	// SimpleDateFormat

class FinalPrep {

//** arrays for saving
static String firstNameArray[] = new String[0];
static String lastNameArray[] = new String[0];
static float gradeArray[] = {};

public static void main(String args[]){
		readInFile();

		System.out.println(" Sorted By last name ");
		sort(lastNameArray);

		for (int i= 0; i < lastNameArray.length; i++)
		{
		 System.out.println(firstNameArray[i] + " " + lastNameArray[i] + " "
			+ gradeArray[i]);
	    }

		System.out.println("\n\n\n Sorted By first name");
		sort(firstNameArray);

		for (int i= 0; i < lastNameArray.length; i++)
		{
		 System.out.println(firstNameArray[i] + " " + lastNameArray[i] + " "
			+ gradeArray[i]);
	    }


}  //end main

//*************************** enlarge ****************************************
	static private float[] enlargeArray(float[] currentArray)
	{
		float[] newArray = new float[currentArray.length +1];
		for (int i = 0; i<currentArray.length; i++)
			newArray[i] = currentArray[i];
		return newArray;
	}


	static private String[] enlargeArray(String[] currentArray)
	{
		String[] newArray = new String[currentArray.length +1];
		for (int i = 0; i<currentArray.length; i++)
			newArray[i] = currentArray[i];
		return newArray;
	}

// *********************** read in the file **************************************************
	static private void readInFile()
	{

	String filename = "C:\\Documents and Settings\\KoKo\\My Documents\\Judy's Classes\\Java Final\\StudentGrades.dat";

	// Streams for reading in data
	DataInputStream input;
	FileInputStream finStream = null;

	// variables
	String firstName,lastName;
	float grade;
	int totalBytes = 0;


	File f1 = new File(filename);		// create a file object
  	if ((f1.exists()) && (f1.isFile()))		//check to see if the file exists and is a file
    {
       System.out.println("The file " + f1.getName() + " exists");
       System.out.println(" ");

	// try to open the input file and read all the data
	try {

	   finStream = new FileInputStream(f1);
	 	input = new DataInputStream(finStream);

	    while (finStream.available() !=0)  //as long as there are more bytes to read
		{
			
		    firstName =input.readUTF();
			lastName =input.readUTF();
			grade = input.readFloat();


			// enlarge and add data to array
			firstNameArray = enlargeArray(firstNameArray);
			lastNameArray = enlargeArray(lastNameArray);
			gradeArray = enlargeArray(gradeArray);

			firstNameArray[firstNameArray.length-1] = firstName;
			lastNameArray[lastNameArray.length-1] = lastName;
			gradeArray[gradeArray.length-1] = grade;

			
		} //end while

	} //end try
	

	catch (EOFException eEOF)	
	     { System.out.println("End of listing"); }

	catch (IOException eIO) {		// any other IO error?
		System.out.println("Exception is :- " + eIO);  }

	// what do I want to do no matter what.
	finally
	{
		System.out.println(" ");
		try		//attempt to close the file
			{ finStream.close(); }
		catch (IOException e)	
			{ System.out.print("Exception is :- " + e); }
	} // end finally

} //end true portion of if
else
	{
	System.out.print ("The file " + f1.getName() + " does not exist.");
	System.exit(1);
	}

	}//end readInFile


//***************************** sort routines *********************************************
	//method to sort arrays
	private static void sort(String tempArray[])
	{
		// loop to control number of passes
		for (int pass = 0; pass < tempArray.length-1; pass++)
		{
			for (int element = pass; element < tempArray.length; element++)
				if (tempArray[pass].compareTo(tempArray[element])>0)
				{
					swap(firstNameArray, pass, element);
					swap(lastNameArray, pass, element);
					swap(gradeArray, pass, element);

				}
		}
	}

		private static void sort(float tempArray[])
		{
			// loop to control number of passes
			for (int pass = 0; pass < tempArray.length-1; pass++)
			{
				for (int element = pass; element < tempArray.length; element++)
					if (tempArray[pass] > tempArray[element])
					{
						swap(firstNameArray, pass, element);
						swap(lastNameArray, pass, element);
						swap(gradeArray, pass, element);

					}
			}
	}

	// method to swap two elements of an array
	private static void swap(String swapArray[], int first, int second)
	{
		String hold;  // temporary holding area for swap
		hold = swapArray[first];
		swapArray[first] = swapArray[second];
		swapArray[second] = hold;
	   	}

	private static void swap(float swapArray[], int first, int second)
	{
		float hold;  // temporary holding area for swap
		hold = swapArray[first];
		swapArray[first] = swapArray[second];
		swapArray[second] = hold;
	   	}


}  //end class

This is what is in the data file:

James Wood 94
Meshell Doan 100
Yoli Crespo 87
Samuel Beck 51
Polo Koren 82
Dylan Bunson 64
Michael Kore 99
Mya Young 100
Annie Lee 89
Wayne Smith 79

Edited 7 Years Ago by jko2326: n/a

I don't know. Why don't you add a few more println() statements to see how far you're getting in the program and where it's breaking down?

At the very least, post what you suspect the problem is. Help people help you instead of just asking "why doesn't this work".

I don't know. Why don't you add a few more println() statements to see how far you're getting in the program and where it's breaking down?

At the very least, post what you suspect the problem is. Help people help you instead of just asking "why doesn't this work".

It's not reading in the file, it goes straight to the catch "catch (EOFException eEOF)"
and im not sure why. When i have data in my file?

Perhaps you should

eEOF.printStackTrace()

and see what the stack trace has to say on it. Your custom error message isn't telling you much.

This article has been dead for over six months. Start a new discussion instead.