I need help in multiple files!!!Please...

Question

I already have a working class for this part.All I need is the application part that will create a property object for each data line read from the the input file assign4.dat. This application should also print each object to a data file, according to its category. If category 1, properties should be printed out to out1.dat, category2 to out2.dat, category 3 to out3.dat, and the rest to outRest.dat..Please help me start off my program.. I am a new programmer trying to learn new things..I would appreciate all your help..here is my working class, that works perfectly fine..and also the assign4.dat, for ur better understanding..Tnx..
import java.util.StringTokenizer;
import java.io.*;
public class Property{
     private int category;
     private double sellingPrice;
     private double commissionRate;
     private double commission;
     public void Property(String s){
          StringTokenizer tokenizer=new StringTokenizer(s);
          category=Integer.parseInt(tokenizer.nextToken());
          sellingPrice=Double.parseDouble(tokenizer.nextToken());
     public void Property(int cat, double selP){
          cat=category;
          selP=sellingPrice;
     public void setCommissionRate(){
          if(category==1)
          commissionRate=0.04;
          if(category==2)
          commissionRate=0.06;
          if(category==3)
          commissionRate=0.071;
     public void setCommissionRate(int i){
          if((i>=1)&&(i<=3))
               category=i;
               this.setCommissionRate(i);
          else
               commissionRate=i;
     public double getCommission(){
          commission=sellingPrice+commissionRate;
          return commission;
     public double getCategory(){
          return category;
     public String toString(){
          return "Price: "+sellingPrice+ " Category: "+category+ " Commission Rate: "+ commissionRate + " Commission: "+ commission;
}//end of property
//start of assign4.dat
1 457000
3 14550
2 49000
1 189000
2 24340
3 156700
3 78900
1 39000
1 345500
1 789000
2 550000
1 23500
4 78000
1 45000
5 899999

Answer 1

tnx again walken..but how do u extract the category part in the textfile..like the 1, 2, 3 for u to be able to print it out on a textfile those things..like read a line of text and then know whether it is 1, 2, 3..like i tried using the substring but then i had an error reading it...thats where i got stucked..here's the program..
import java.io.*;
import java.util.*;
public class TestProperty{
     public static void main(String args[]){
     //     String line;
     Property myProperty= new Property();
          try{
          FileReader inStream=new FileReader("assign4.dat");
          BufferedReader ins= new BufferedReader(inStream);
          FileWriter outStream=new FileWriter("out1.dat");
          PrintWriter outs = new PrintWriter(outStream);
          int lines=Integer.parseInt(ins.readLine());
          myProperty.getCategory();
          myProperty.getCommission();
          System.out.println(myProperty.toString());
     //     while(line!=null)
          for(int lineCount=0;lineCount<lines;lineCount++){
               String line=ins.readLine();
          //     line=ins.readLine();
               if(line.substring(0)=="1")
               outs.println(line);
               System.out.println(lines+"data lines written to file ");
          outs.close();
          ins.close();
          catch (IOException e){     
          System.out.println("i/o error:"+e.getMessage());
          e.printStackTrace();
          catch(NumberFormatException e){
               System.out.println(e.getMessage());
               e.printStackTrace();
}