Parse file into arrayList

[zenitis]

Hello there and thanks in advance for your help. I have got .obj file and i want to open it and parse it to a arrayList. The file has the following format:

# produced by mview OBJ exporter
# 

g main
v -0.021198 0.127200 0.009153
v -0.014447 0.128935 0.009035
f 1316 1041 1319
f 1318 1316 1319
f 77 109 1010

I want to store in arrayList the numbers and the prefix. I ve already read it with the following code:

FileInputStream fstream = new FileInputStream("lagos.obj");
          // Get the object of DataInputStream
          DataInputStream in = new DataInputStream(fstream);
          BufferedReader br = new BufferedReader(new InputStreamReader(in));
          String strLine;
          //Read File Line By Line
          while ((strLine = br.readLine()) != null) {
              // Print the content on the console
              System.out.println(strLine);

          ArrayList<ArrayList<String>> array;
          array = new ArrayList<ArrayList<String>>();
          }
          
          System.out.print(strLine);
          //Close the input stream
          in.close();

I didnt manage to store it in the arrayList. Any help would be appreciated!!

[sunde887]

It's fairly simple. Before the line with the while loop, declare the array list. Then as you go through the loop, add strLine to the array list.

ArrayList<String> array = new ArrayList<String>();
loop
  split line
  loop
    store each item in array list
  end loop
end loop

[zenitis]

:D yes i got it. In that way I have a 2d array list. I can have access with array.get(1) to the line but how can I have access to the elements of the line?

By the way thanks for the help.

[sunde887]

You stored it in a 2d array list, so each element in the array list IS an array list.

if you have the following declaration

ArrayList<ArrayList<String>> info = new ArrayList<ArrayList<String>>();
info.get(0); //this returns an array list, which you can then search as well.
//can be written like this
ArrayList<String> piece = info.get(0);
//then you can search the second part
piece.get(0); //returns item located at 0, 0.

[zenitis]

I ve tried this but it doesnt work out:

            ArrayList<ArrayList<String>> array1 = new ArrayList<ArrayList<String>>();


            for(int i=1; i<5768; i++){
               ArrayList<String> array = new ArrayList<String>();

              while ((strLine = br.readLine()) != null) {

                  //ArrayList file =
                  array.add(strLine);

          }

             array1.add(i, array);

          }
           
         System.out.println(array1);

[sunde887]

What happens? Errors? If so, please post them as they appear. Or is it a logical problem?

To understand, your goal is to store each line of the file in it's own array list?

[zenitis]

with that code:

ArrayList<String> array = new ArrayList<String>();

              while ((strLine = br.readLine()) != null) {
                  array.add(i,strLine);
          }
          }

you have all the file in one single dim arrayLIst. But now i do not have access to a specific element of the file but only to specific lines of the file (for example array.get(1) corresponds to [v -0.021198 0.127200 0.009153]). I want something like array.get(1).get(1) = ''v''.

[sunde887]

You should do something like this

String[] input = line.split(" ");

This will produce an array of x elements, split based on spaces. Then you can loop through the array, adding each element to the array list. Finally, you can add the array list to the main array list.

[DarrylBurke]

Or by coding to the interface, you can use the Arrays.asList(...) method.

List<List<String>> list = new ArrayList<List<String>>();
:
:
list.add(Arrays.asList(line.split(" ")));

db