Reading file to arraylist with multiple data type

Question

I have a problem with reading from a text file to an arraylist. The problem is that i don't know how to read in multiple types, because in my arraylist there are Points, Strings, booleans, therefor linesplit doesn't work. I checked all the topics and didn't find a solution to this.

edit: Elrendezes class looks like

  class Elrendezes {
   protected Point Po;
   protected String hely;
   protected String foglalo;
   protected boolean foglalt;
  }

Here's how my file looks like:

 java.awt.Point[x=16,y=13], 1, name1, false

And the method to read is

public static ArrayList<Elrendezes> readDataFromFile(){
      ArrayList<Elrendezes> ElrList = new ArrayList<Elrendezes>();
      FileInputStream fstream = null;
      try
      {
          fstream = new FileInputStream("src/files/DataFile.txt");
          BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
          String strLine = null ;
          String tokens[] = strLine.split(", ");


          while ((strLine = br.readLine()) != null)   {
           tokens = strLine.split(", ");
          // THIS DOES NOT WORK: ElrList.add(new Elrendezes(tokens[0], tokens[1], tokens[2], tokens[3]));
          }
      }
      catch (IOException e) {
        e.printStackTrace();
      }
      finally {
          try { fstream.close(); } catch ( Exception ignore ) {}
      }
      return ElrList;

}

THIS DOES NOT WORK what doesn't work can please say a little bit about the error you are getting — Abubakkar
– Abubakkar, Commented Nov 26, 2012 at 13:32
How is the data file written? Did someone else wrote it? Do you have access to this code? — UmNyobe
– UmNyobe, Commented Nov 26, 2012 at 13:34
i make the file, and this is the error: constructor Elrendezes(String, String, String, String) is undefined, this is because the constructor of Elrendezes is Point, String, String, Boolean — Balázs Csíkos
– Balázs Csíkos, Commented Nov 26, 2012 at 13:37
i might just make a point to string function, that'll probably help — Balázs Csíkos
– Balázs Csíkos, Commented Nov 26, 2012 at 13:39

UmNyobe · Accepted Answer · 2012-11-26 13:53:08Z

1

As you probably dont know regular expressions, I will use:

Get x and y:

int v1 = strLine.indexOf("x=");
int v2 = strLine.indexOf(",y=");
int v3 = strLine.indexOf("]")  ; 
string x = strLine.substring(v1 +2, v2);
string y = strLine.substring(v2 +3, v3);

Break point representation from the rest.

string secondpart = strLine.substring(v3+1);

Now break secondpart with only the coma as separator.
Convert string representation, using Integer.parseInt() and etc..
Construct your object back.

Note: written in a hurry, check if the indexes used for x, y and secondpart are correct. I also assumed the input is correct.

answered Nov 26, 2012 at 13:53

UmNyobe

23.1k10 gold badges64 silver badges90 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Pim_D · Accepted Answer · 2012-11-26 13:57:21Z

0

I think you have to choose a char to split the String.

Cast the split string into boolean, integer etc.

Elrendezes(String[] s){
Point Po = s[0]; // dont know how to cast string to point, never done before
hely = s[1];
foglalo = s[2];
foglalt = Boolean.parseBoolean(s[3]);
}

answered Nov 26, 2012 at 13:57

Pim_D

891 silver badge10 bronze badges

Collectives™ on Stack Overflow

Reading file to arraylist with multiple data type

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related