Reading Individual Lines of Text Into An ArrayList or Vector From A File

Question

I am trying to read each individual line of text of a .txt file into an ArrayList or Vector. I seem to get the same results no matter which Object I am using (ArrayList or Vector). The text file is a comma-delimited text file to be used as a database. I want to separate each line as an individual record then dump it into an ArrayList or Vector and have them loop through a StringTokenizer() class so that I can be sure each line has the correct number of fields before I commit it to a serialization file. Currently, the proper amount of records seems to be forming in the initial part of the program, I am just remiss at properly placing them in the Vector, or StringTokenizer classes so I can further manipulate them. I'm using the LineNumberReader class to get line numbers to use as record numbers and for loop indexes. I'm not sure (obviously) if this is a correct way to do it or not.
Any help is greatly appreciated in advance.
Thanks for all your time.
int n = 0;
          try {
                * read each individual line and count it as a separate record. 
                * place each record into an array or may be a string if it has 9 tokens
                * if a record hasn't got 9 tokens, it isn't a record
                * place each array or string into a Vector
               in = new LineNumberReader(new FileReader(filename));
                         while ((record = in.readLine()) != null) {
                         n = in.getLineNumber();
                         rawData = new Vector();     
                         for (int i = 0; i < n; i++) {
                              rawData.add(record);     
                         if (record == null)
                         break;
*The following System.out.println() statement shows that all lines are correctly retrieved from the text file
*as separate records
                    System.out.println("Record No. " + n +  "= " + record);     
               //Debug
/** When these print lines execute it reveals that only the last record has been inserted into the Vector as
*    many times as I have records in the text file.
                    System.out.println("Number of Records = " + n);
                    System.out.println("VectorSize = " + rawData.size());
                    System.out.println("First rawDataElement = " + rawData.firstElement());
                    System.out.println("Second rawDataElement = " + rawData.get(1));
                    System.out.println("Third rawDataElement = " + rawData.get(2));
                    System.out.println("Fourth rawDataElement = " + rawData.lastElement());
*  Next run each record through a StringTokenizer to be sure that there the correct number of fields present
*  If it contains the correct number of fields, dump it into an alternate ArrayList or Vector.
*  As it is now, the StringTokenizer gives a NullPointerException
                    for (int i = 0; i < n; i++) {
                         StringTokenizer recordSet = new StringTokenizer((String) table.get(n), ",");
                             while (recordSet.hasMoreTokens()) {
                                 if (recordSet.countTokens() == 9) {
                                       data = new Vector();
                                       data.add((Object) recordSet.nextToken(","));
                                       System.out.println("Vector data size = " + data.size());
                                       System.out.println("Second dataElement = " + data.get(0));
                        System.out.println("String Tok recordSet = " + recordSet.countTokens());                                  System.out.println("Number of Records = " + n);
                    System.out.println("First dataElement = " + data.firstElement());
                    System.out.println("Second dataElement = " + data.get(0));
                    System.out.println("Third dataElement = " + data.get(2));
                    System.out.println("Fourth dataElement = " + data.lastElement());
               } catch (FileNotFoundException e) {
                    System.out.println(e);
               } catch (IOException e) {
                    System.out.println(e);
     }

Answer 1

I think your logic is broken.
rawData = new Vector();
creates a new instance of Vector for every record.
Your add() within a for loop adds the same record to the Vector n times. I think what you really want is something like this:in = new LineNumberReader(new FileReader(filename));
rawData = new Vector();
while ((record = in.readLine()) != null) {
    n = in.getLineNumber();
    rawData.add(record);     Mark