Array list and Iterator

[jin kazama]

Good evening, can I ask for some guidance with an issue I have with a small program?

I am having problems with a couple of classes using an ArrayList and an Iterator with a scanner reading in a file. When the file has been read in and another class attempts to return the elements in the Iterator, it only reports back every other entry from the file. So the file File1.txt contains 10 rows of Computer names, but when the program runs it only reports back 5 of the names.

The Class data is:

public class ImportData{
    public static void main(String args[]) {
 
	try {
   		DataImport firstDataFile = new DataImport ("File1.txt");

            	while (firstDataFile.getTheData() != "DONE"){
                System.out.println(firstDataFile.getTheData());
                
            }

The next class is:

public class DataImport {


    File file = new File("fileName");
    ArrayList<String> dataFileList = new ArrayList<String>();
    Iterator<String> iter;
    String DONE = "DONE";
    Scanner sc;

    public DataImport(String dataFile)throws FileNotFoundException {
        
        sc = new Scanner(new File(dataFile));
        
        while (sc.hasNextLine()){
            
            			dataFileList.add(sc.nextLine());
        			}
        	iter = dataFileList.iterator();
        	sc.close();

		}

    public String getTheData()throws EmptyFileException {

        while (iter.hasNext()) {
            
            
            return iter.next();
            // System.out.println(iter.next());
        }
        return DONE;
    }

Thank you in advance.

Jin.

[Doug Braidwood]

When you are running this to test it, do you have

// System.out.println(iter.next());

uncommented?

That would explain things.

[Doug Braidwood]

To clarify iter.next() is returning the next value and moving the iterator on.
So if you System.out(iter.next());
and then return(iter.next());
then you will take your 10 values and output 5 of them to the screen and return the other 5 from the function.

[Jesper de Jong]

Welcome to JavaRanch.

Please UseCodeTags when you post source code - I've added them for you in your post above.

[Dhan Kumar]

I got it....one different reason which exactly explains the flaw.
See the below code

  try {  
        DataImport firstDataFile = new DataImport ("File1.txt");  
  
                while (firstDataFile.getTheData() != "DONE"){  
                System.out.println(firstDataFile.getTheData());  
                  
            }   

getTheData method is called twice that explains why you get only half of the text from file.

try this : this will work.

  try {  
        DataImport firstDataFile = new DataImport ("File1.txt");  
                String temp="NOTDONE";
                while (!temp.equal ("DONE")){  
                temp = firstDataFile.getTheData();
                System.out.println(temp);  
                  
            }   

[jin kazama]

Thank you all for your kind advice.

The solution posted by Dhan has resolved the issue.

Cheers

Jin.