PROOF READ: Sort text file 3 different ways and compare

[VinceGuad]

If you wouldn't mind could I have someone please proof read my code and give me pointers as to how I can complete my program, I am stuck as of right now. The purpose of my program is to basically utilize three sorting algorithms, bubblesort, insertion sort and selection sort. I am to sort a text file in ascending order. For example, apple should come before banana and banana before orange. Here is what I have so far.

public interface InterfaceStringArray
{
	public void initialize(int arrSize);
	//initializes an array of size=arrSize
	
	public int getSize();
	//returns the current array size
	
	public void insert(String newItem); 
	//inserts newItem in the next available spot
	
	public boolean delete(String deleteItem); 
	//returns true if all occurrences of deleteItem are deleted, 						  
	//false if no matching items found
	
	public int search(String searchItem); 
	//returns the index of the first matching item, -1 if no match
	
	public boolean setItem(int index, String itemValue); 
	//returns true if successful, false otherwise
	
	public String getItem(int index); 
	//returns the item at the requested index
	
	public boolean resize(int newSize); 
	//returns true if successful (widening), false if narrowing
	
	public void swap(int one, int two);
	//swaps strings
	
	public void bubbleSort();
	//sorts the array strings using Bubble Sort Algorithm (ascending)
	
	public void selectionSort();
	//sorts the array strings using Selection Sort Algorithm (ascending)
	
	public void insertionSort();
	//sorts the array strings using Insertion Sort Algorithm (ascending)
	
	public String getStringArray(); 
	//returns a String of all the array strings separated by a white space
}

The 4 methods that are currently blank I am unsure of, any pointers or peer edits that would help me see what statements would be used here would be greatly appreciated.

public class StringArray implements InterfaceStringArray
	{

	private String a[];			 //reference to array a
	private int nElems;			// number of data items

//--------------------------------------------------------------
	
public void initialize(int arrSize)
	{	
	a = new String[arrSize]; 	//initializes an array of size=arrSize
	nElems = 0;			   		//sets the number of data items to 0
	
	}
//--------------------------------------------------------------
	
public int getSize()
	{
		{ return nElems; }		//returns the current array size
	}

//--------------------------------------------------------------

public void insert(String newItem)
	{
	a[nElems] = newItem;
	nElems++; 					//inserts newItem in the next available spot
	}
	
//--------------------------------------------------------------

public boolean delete(String deleteItem)
	{
	int j;
	for (j=0; j<nElems; j++)
		if( deleteItem == a[j] )
			break;
	if(j==nElems)
		return false;			//false if no matching items found
	else
		{
		for(int k=j; k<nElems; k++)
			a[k] = a[k+1];
		nElems--;
		return true;			//returns true if all occurrences of deleteItem are deleted
		}
	}//end delete()

//--------------------------------------------------------------						  
	
public int search(String searchItem)
	{
	int j;
	for(j=0; j<nElems; j++)
		if(a[j] == searchItem)
			break;
	if(j == nElems)
		return -1;
	else
		return j;
	}
//--------------------------------------------------------------

public boolean setItem(int index, String itemValue)
	{
	//returns true if successful, false otherwise
	}

//--------------------------------------------------------------

	public String getItem(int index)
	{
	//returns the item at the requested index
	}

//--------------------------------------------------------------	
	
public boolean resize(int newSize) 
	{
	

	}

//--------------------------------------------------------------	

public void swap(int one, int two) 
	{
	String temp = a[one];
	a[one] = a[two];
	a[two] = temp;
	}

//--------------------------------------------------------------

public void bubbleSort()
{
int out, in;

for(out=nElems-1; out>1; out--)   			// outer loop (backward)
   for(in=0; in<out; in++)        			// inner loop (forward)
      if(a[in].compareTo(a[in+1]) < 0)      // out of order?
         swap(in, in+1);         		    // swap them
}  // end bubbleSort()

//--------------------------------------------------------------	
public void selectionSort()
{
    int out, in, min;

    for(out=0; out<nElems-1; out++)   			// outer loop
       {
       min = out;                     			// minimum
       for(in=out+1; in<nElems; in++) 			// inner loop
          if(a[in].compareTo(a[in+1]) < 0 )     // if min greater,
              min = in;              		    // we have a new min
       swap(out, min);               		    // swap them
       }  // end for(out)
    }  // end selectionSort()

//--------------------------------------------------------------	
public void insertionSort()
{
    int in, out;

    for(out=1; out<nElems; out++)     			// out is dividing line
       {
       String temp = a[out];           			// remove marked item
       in = out;                      			// start shifts at out
       while(a[in].compareTo(a[in+1]) < 0) 		// until one is smaller,
          {
          a[in] = a[in-1];           			// shift item to right
          --in;                      			// go left one position
          }
       a[in] = temp;                  			// insert marked item
       }  // end for
    }  // end insertionSort()

//--------------------------------------------------------------
public String getStringArray()
	{
	//returns a String of all the array strings separated by a white space
	}
	
}

This is my driver .java file. Which will include the main method. Not sure of the entire structure of this .java file. I'm thinking I will need to use a bufferreader to read the .txt file. Then I should I create 3 tokenizers or is only one neccessary? I think I need to create 3 objects, and then sort each object using a different sorting algorithm. Once each has been sorted, I must compare all three then write a final method which says "gj they all match" which I will have no problem with.

public class StringArrayApp {

	
}

[Steve11235]

One thing...

deleteItem == a[j]

Use deleteItem.equals(a[j]). a == b, for objects, checks that they are the same instance, which is very restrictive.

[VinceGuad]

That you for that correction. Do you beleieve my StringArray looks correct so far as to the task I am trying to accomplish?

Could anyone give me any pointers as to how I can tackle the last 4 remaining methods?

Also, I will now begin to write my StringArrayApp to drive the program and use the methods I have written.

Since I am sorting the same text file 3 different ways do I need to use 3 string tokenizers? Also when using a string tokenizer its neccessary to use a file buffer to read the text file correct? I am unfirmilar with these statements could someone provide some direction?