Read & write from external files in java

Question

Hello everybody,
I need your help in two problems. I have to write a method that read specific numbers from a file, save them in an array, do some calculation on that array and write it again in a new file.
For example, I have a file that contains the following:
#VRML V1.0 ascii
Material {
diffuseColor [ 1 1 1 ]
ShapeHints {
vertexOrdering COUNTERCLOCKWISE
shapeType UNKNOWN_SHAPE_TYPE
Coordinate3 {
point [
          1 0 0 ,
          1 1 0 ,
          1 1 1 ,
          1 0 1 ,
          0 1 0 ,
          0 1 1 ,
          0 0 1 ,
          0 0 0 ,
IndexedFaceSet {
coordIndex [
0,1,2,-1,
0,2,3,-1,
1,4,5,-1,
1,5,2,-1,
3,2,5,-1,
3,5,6,-1,
0,3,6,-1,
0,6,7,-1,
6,5,7,-1,
7,5,4,-1,
0,7,4,-1,
0,4,1,-1,
I need to read the point coordinates only and save them in a two dimension array, then I'll do some transformation on that array and write it in a new file that contains the previous data but the point coordinates are the transformed coordinates. I tried the following:
FileReader in = new FileReader("C:\\hexahedron.txt");
          BufferedReader br = new BufferedReader(in);
          String line;
          StringTokenizer s;
          int [][] point = new int [8][3];
          int row = 0;
          int column;
          while ( (line = br.readLine()) != null) {
               s = new StringTokenizer(line);
               column = 0;
               while (s.hasMoreTokens()) {
                    if ( s.nextToken() == "[" ){
                         point [row][column++] = Integer.parseInt(s.nextToken());
               row++;
          br.close();
          in.close();
But when I tried it, I found out that it saves 0s in the array!
As I mentioned before, my problem is that I don't know how to read specific information from a file. I know how to write new information a file, but how to write a file that I already have with changed specific information.
I'll be grateful if you show me how to solve those problems.
And I hope that I explained my problems in an understandable and clear way.
Regards,

Answer 1

if ( s.nextToken() == "[" ){should beif (s.nextToken().equals("["){Also, you have two nextToken for each has hasMoreTokens, which is going to cause an exception.
You are never hitting the parseInt code because of your equals/== error. Therefore, everything is zeros.
The order of reading lines and checking for "[" isn't right. You should find the [ (maybe including the "point" word), then get numbers from the following lines (read line, tokenize, read line, tokenize, ...) until you hit the end of the points.