Reordering within a text file

Question

HI all,
I have a text file in the following format
Part 1     Part 2
p2_f1     p2_f2     p2_f3     p2_f4     p2_f5     p2_f6          
p1_f1     p1_f2     p1_f3     p1_f4     p1_f5     p1_f6
the above file is tab delimited
I would like to reorder the file in such a way that
when first word of the first line is " Part 1" then the second line should be
p1_f1     p1_f2     p1_f3     p1_f4     p1_f5     p1_f6
if the second word in the first line is " Part 2" then the third line should be
p2_f1     p2_f2     p2_f3     p2_f4     p2_f5     p2_f6
basically the lines after the first line in the text file should be sorted based on the words in the first line.
Any ideas on how I could proceed?
Thanks in advance.

Answer 1

Hello ,
I have changed the code to initialize the hashmap.
My code is
import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Reorder {
    public static void main(String args[]) throws IOException {
        FileInputStream fstream = null;
        try {
            fstream = new FileInputStream("E:\\Documents\\reorder.txt");
//Variable Declarations
            String strLine;
            Map<String, String> entries = new HashMap<String, String>();
            ArrayList<String> partlist = new ArrayList<String>();
// Get the object of DataInputStream
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            while ((strLine = br.readLine()) != null) {
// Intialize tokenizer
                String s = strLine;
                StringTokenizer tokenizer = new StringTokenizer(s, "\t");
                while (tokenizer.hasMoreTokens()) {
// add data to collection
                    partlist.add(tokenizer.nextToken());
// Sort The data
                    Collections.sort(partlist);
// Adding to hashmap
                    String key = strLine.substring(0, 2).replace("p", "Part ");
                    entries.put(key, strLine);
//                    System.out.println(partlist);
// Printing the hashmap
            System.out.println(entries);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Reorder.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            try {
                fstream.close();
            } catch (IOException ex) {
                Logger.getLogger(Reorder.class.getName()).log(Level.SEVERE, null, ex);
}But I have no clue as to how to add the read line part
String firstLine = readFirstLine();
String[] parts = split(line);and the write part
write(firstLine);
for(String part: parts){
   write(entries.get(part));
}my output now looks like this
{Pa=Part 1        Part 2, Part 1=p1_f1        p1_f2        p1_f3        p1_f4        p1_f5        p1_f6, Part 2=p2_f1        p2_f2        p2_f3        p2_f4        p2_f5        p2_f6}
Thanks in advance.
Edited by: Spry.chipper on Dec 13, 2009 10:53 AM