java hashmap

hello sir ,
To write a java program that parses a text file input.txt and the output of the program is a concurrent hashmap in the specified format.The below program makes use of vector data stucture to do this.Please modify this program so that the program should use hashmap data structure for parsing and outputing.please help me.
Program.java:

Code:

import java.io.*;
import org.w3c.dom.Document;
import org.w3c.dom.*;
import java.util.*;

class ConfigLine
{
	public Vector ctrlRtrList = new Vector();
	public Vector grpAddr = new Vector();
	public Vector srcList = new Vector();
	public Vector rtrList = new Vector();
	public Vector rPSpecs = new Vector();

	public void readData() throws IOException
	{
		BufferedReader filein = getFileStream();

		if (filein == null)
		return;


		String currentLine = null;

		// Read line by line
		while((currentLine = filein.readLine()) != null )
		{
			// Ignore comments
			if (currentLine.startsWith("#"))
			continue;

			else
			{
	StringTokenizer st=new StringTokenizer(currentLine, ":");

				int i=0;
				while (st.hasMoreElemen())
				{
		String tList(st.nextElement()).toString();
					++i;
					switch (i)
					{
					case 1:
			fillVector(tList,ctrlRtrList); //Fill the vector with the list values
						break;

	                            case 2:grpAddr.addElement(tList);
						break;

		case 3:
                                      fillVector(tList,srcList);
						break;

		case 4:
		fillVector(tList,rtrList);
						break;

                                  case 5:
			fillVector(tList,rPSpecs);
						break;
					
}
				}
			}
		}
	}

	public void fillVector(String listStr, Vector v)
	{
	StringTokenizer st1=new StringTokenizer(listStr, ",");
		while (st1.hasMoreElements())
		{
			v.addElement(st1.nextElement());
		}
	}

	// Gets the defaults file input stream as a buffered reader
	private static BufferedReader getFileStream()
	{
		try
		{
	FileReader fr = new FileReader(new File("input.txt"));
		BufferedReader br = new BufferedReader(fr);
			return br;
		}
		catch(FileNotFoundException fnfeEx)
		{
			System.out.println(fnfeEx.toString());
			return null;
		}
	}

	public void readVector()
	{
		if(ctrlRtrList.size()==0)
		System.out.println("\nNo Elements\n");
		else
		{
		System.out.println("Control Router List:");
			for(int i=0;i<ctrlRtrList.size();i++)
		System.out.println(ctrlRtrList.elementAt(i));
		}

		if(grpAddr.size()==0)
		System.out.println("\nNo Elements\n");
		else
		{
		System.out.println("Group Address:");
		System.out.println(grpAddr.elementAt(0));
		}

		if(srcList.size()==0)
		System.out.println("No Elements\n");
		else
{
			System.out.println("Source List:");
			for(int i=0;i<srcList.size();i++)
		System.out.println(srcList.elementAt(i));
		}

		if(rtrList.size()==0)
		System.out.println("No Elements\n");
		else
		{
			System.out.println("Router List:");
			for(int i=0;i<rtrList.size();i++)
		System.out.println(rtrList.elementAt(i));
		}

		if(rPSpecs.size()==0)
		System.out.println("No Elements\n");
		else
		{
			System.out.println("RP-Specs List:");
			for(int i=0;i<rPSpecs.size();i++)
		System.out.println(rPSpecs.elementAt(i));
		}
	}
}


class Program
{
	static ConfigLine cl=new ConfigLine();
	public static void main(String argv[])
	{
		try
		{
			cl.readData();
		}
		catch(Exception e)
		{
		System.out.println("Wow u'v an exception");
		}

		cl.readVector();
	}
}

input.txt:

#Format:
# <CtrRtrList>:<GrpAddr>:<SrcList>:<RtrList>[:RP-spec]
10.2.32.82:239.192.0.2:10.00.5.183,10.0.6.185:10.2.32.85,10.2.32.81,10.2.32.82:10.0.2.82,,10.2.78.42

 

What does hashmap ? Please explain.. It takes filename as an Input and what would be the output in the sense of hashmap ? Thank you.

 

I am sure you will find a good response!!
Good luck for you.