JAVA : file I/O

Question

I have got two text files with data in the following format

data.txt file as following format

A 10
B 20
C 15

data1.txt file is in format (start node,end node, distance):

A B 5 
A C 10
B C 20

I am trying to implement a search strategy, for that I need to load the data from data.txt and ONLY the start node and end node from data1.txt (i.e. I dont need the distance). I need to store this information in a stack as I think it would be a best data structure for implementing greedy search.

Actually I am not sure how to get started with file I/O to read these files and store them in array to implement greedy search. So I would highly appreciate any starting idea on how to proceed.

I am new to this, so please bear with me. Any help is much appreciated. Thanks.

EDIT: Here is what I have got till now

String heuristic_file = "data.txt";
try
    {          

        FileReader inputHeuristic = new FileReader(heuristic_file);
        BufferedReader bufferReader = new BufferedReader(inputHeuristic);
        String line;

        while ((line = bufferReader.readLine()) != null)   
        {
            System.out.println(line);
        }

        bufferReader.close(); 

    } catch(Exception e) {
        System.out.println("Error reading file " + e.getMessage());
    }

Answer 1

use split

            while ((line = bufferReader.readLine()) != null)   
            {
                String[] tokens = line.split(" ");
                System.out.println(line + " -> [" + tokens[0] + "]" + "[" + tokens[1] + "][" + tokens[2] + "]");
            }

if you must have this in an array you can use the following:

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;

public class NodeTest {

  public static void main(String[] args) throws ParseException {
    try {          
      File first = new File("data.txt");
      File second = new File("data1.txt");    

      Node[] nodes1 =  getNodes(first);
      Node[] nodes2 =  getNodes(second);

      print(nodes1);
      print(nodes2);
    } 
    catch(Exception e) {
      System.out.println("Error reading file " + e.getMessage());
    }   
  }

  public static final void print(Node[] nodes) {
    System.out.println("======================");
    for(Node node : nodes) {
      System.out.println(node);
    }
    System.out.println("======================");
  }

  public static final Node[] getNodes(File file) throws IOException {
    FileReader inputHeuristic = new FileReader(file);
    BufferedReader bufferReader = new BufferedReader(inputHeuristic);
    String line;
    List<Node> list = new ArrayList<Node>();
    while ((line = bufferReader.readLine()) != null) {
      String[] tokens = line.split(" ");
      list.add(new Node(tokens[0], tokens[1]));               
    }
    bufferReader.close(); 
    return list.toArray(new Node[list.size()]);
  } 
}

class Node {
  String start;
  String end;

  public Node(String start, String end){
    this.start = start;
    this.end = end;
  }

  public String toString() {
    return "[" + start + "][" + end + "]";
  }
}