Hi Friend,

Try the following code:

import java.io.*;
import java.util.*;
class ResApplication  
{
    public static void main(String[] args) throws Exception
    {
        File f=new File("C:/Customer.txt");
        BufferedWriter bw=new BufferedWriter(new FileWriter(f,true));
        Scanner input=new Scanner(System.in);
        for(int i=1;i<=10;i++){
        System.out.print("Enter Customer Name: ");
        String name=input.nextLine();
        System.out.print("Enter Date(yyyy-mm-dd): ");
        String date=input.nextLine();
        bw.write(name+" "+date);
        bw.newLine();
        }
        bw.close();

        System.out.println();
        System.out.print("Enter date to view the list of customers(yyyy-mm-dd): ");
        String d=input.nextLine();
        BufferedReader br=new BufferedReader(new FileReader(f));
        String line="";
        ArrayList list = new ArrayList();
        ArrayList cusList=new ArrayList();
           while ((line = br.readLine()) != null) {
           list.add(line);
            }
           Iterator itr;
           for (itr = list.iterator(); itr.hasNext();) {
           String str = itr.next().toString();
           String[] splitSt = str.split(" ");
           String name = "", date = "";
           for (int i = 0; i < splitSt.length; i++) {
           name = splitSt[0];
           date = splitSt[1];
           if(date.equals(d)){
           cusList.add(name);
           }
           }
           }
           Set set = new HashSet(cusList);
    ArrayList l=new ArrayList(set);
    Collections.sort(l);
    for(int i=0;i<l.size();i++){
    System.out.println(l.get(i).toString());
    }
}
}

Thanks