Thread: Reading file and adding it to an array through a method

I am creating an Array List of zip codes (29000 of them) and I am having trouble getting it to add the complete zipcodes to the arrayList. I think my problem is actually using the ArrayList because it is instantiated in another method.

 
public class ZipCodeDatabase {
 
 private ArrayList <ZipCode> list;
 
    public ZipCodeDatabase() {
        list = new ArrayList<ZipCode>();
    }
 
    public void readZipCodeData (String filename) throws IOException {
        String info;
        Scanner fileReader;
        Scanner lineReader;
 
        fileReader = new Scanner(new File(filename));
 
        while(fileReader.hasNext()) {
            info = fileReader.nextLine();
 
            lineReader = new Scanner(info);
            lineReader.useDelimiter(",");
 
            int zip = lineReader.nextInt();
            String city = lineReader.next();
            String state = lineReader.next();
            double longtitude = lineReader.nextDouble();
            double latitude = lineReader.nextDouble();
 
            ZipCode z = new ZipCode(zip, city, state, latitude, longtitude);
            list.add(z);
        }
}

This uses the ZipCode method which is in another class and has the code

  public ZipCode (int pZip , String pCity , String pState , double pLat , double pLon) {
        zipcode = pZip;
        city = pCity; 
        state = pState;
        latitude = pLat;
        longitude = pLon;
 
 
    }

The class and method names are all given in the project. I'm a beginner Java student and this is my first time posting on these forums so don't hurt me too badly =P

Thanks,
PeskyToaster

I'm am testing out a method called

 
 public ZipCode findZip (int zip) {
        ZipCode p = new ZipCode(0);
        for(int i = 0; i < list.size(); i++) {
            if (list.get(i).getZip() == zip) {
                return list.get(i);
            }
            else {
                return null;
            }
        }
        return p;
    }

It should return the entire Zipcode of the text file, for example the first entry of the file is

99501,ANCHORAGE,AK,61.223145,-149.852843

So if I input 99501 it should return a toString method of the information which is

public String toString() {
        address = city + ", " + state + " " + zipcode;
        return address;
    }

I forgot that the toString is supposed to be in the findZip method as well to format what it returns.

If I input 99501 I should get ANCHORAGE, AK 99501.
What I am getting is null.

I'm also getting a compiler warning of "C:\Users\***\ZipCodeDataBase.java uses unchecked or unsafe operations.
Recompoile with /XIint:unchecked for details."

I hope that is enough information

Why is it only comparing to the first one?

It only returns two empty brackets []. I am just assuming that it is correctly finding the values and something is wrong with adding it into the searchList

This code is supposed to search through the list of zip codes by city or state and add the ones that match to an arraylist then return that arraylist. So if I type in "new" it should return NEWARK zip codes and NEW YORK etc. Here's is my main method for testing this

public class Driver
{
   public static void main(String[] args) throws IOException{
       ZipCodeDatabase t = new ZipCodeDatabase();
 
       t.readZipCodeData("zipcodes.txt");
 
       System.out.println (t.search("al"));
       System.out.println (t.search("chicago"));

The output for "al" gives

[]

The output for "chicago" gives the error

java.lang.StringIndexOutOfBoundsException: String index out of range: 7
at java.lang.String.substring(String.java:1955)
at ZipCodeDatabase.search(ZipCodeDatabase.java:67)
at Driver.main(Driver.java:22)


All copied directly from the BlueJ Terminal Window

This is a different method from the first question. I posted the new method I needed help on, on the first page. It seems it is not adding the found Zip Codes to the array list

I now have

 
 public ArrayList search(String str) {
 
        ArrayList<ZipCode> searchList = new ArrayList<ZipCode>();
        int i = 0;
        while (i < list.size()) {
            str.toUpperCase();
            if ((list.get(i).getCity().substring(0 , str.length()).equals(str)) || (list.get(i).getState().substring(0 , str.length()).equals(str))) {
                searchList.add(list.get(i));
 
            } 
            return searchList;
        }
        return null;
    }

And it still gives the same output

I see that it skips right to null but I need to have it there somewhere. I know that I was missing an i++ to keep it going along the while loop. What should I return at the end and where in the loop?

 
public ArrayList search(String str) {
 
        ArrayList<ZipCode> searchList = new ArrayList<ZipCode>();
        int i = 0;
        while (i < list.size()) {
            str.toUpperCase();
            if ((list.get(i).getCity().substring(0 , str.length()).equals(str)) || (list.get(i).getState().substring(0 , str.length()).equals(str))) {
                searchList.add(list.get(i));
 
 
            } 
            //return searchList;
 
            i++;
            return searchList;
        }
 
    }

I'm getting a compile error because it is missing a return statement at the end.

I got the above to work but it prints it out all on one line which I can fix. I have a distance method to find the distance between to inputted zip codes

 
 public int distance (int zip1 , int zip2) {
        final double EARTH_RADIUS = 3959;
        int distance;
        double p1 , p2 , p3;
 
        ZipCode z1 = findZip(zip1);
        ZipCode z2 = findZip(zip2);
 
        double lat1 = Math.toRadians((z1.getLatitude()));
        double lat2 = Math.toRadians((z2.getLatitude()));
        double long1 = Math.toRadians((z1.getLongitude()));
        double long2 = Math.toRadians((z2.getLongitude()));
 
        p1 = (Math.cos(lat1)) * (Math.cos(long1)) * (Math.cos(lat2)) * (Math.cos(long2));
        p2 = (Math.cos(lat1)) * (Math.sin(long1)) * (Math.cos(lat2)) * (Math.sin(long2));
        p3 = (Math.sin(lat1)) * (Math.sin(lat2));
 
        distance = (int)((Math.acos(p1 + p2 + p3)) * (EARTH_RADIUS));
 
        return distance;
 
    }

The math is off though because if I input 49401 and 90001 the output should be 1841 miles but my output is 2229. I also need to have an if that doesn't accept null values for the entered zips (if zip1 is not on the list) and I have no idea how to do that.