Java read in a text file and then separate into separate arrays

Question

I have a text file which is read in. It has delimeters which are <.> . There is a main subject then there are three paragraphs. Lets say title, section1, section2, section3, and then the next article.

How can I store the data so that ArrayList one will have all the titles, ArrayList 2 will have all the section1 information, etc.? I want be able to output these arrays.

E.g.:
Large storm on its way.

about the large storm

statics on storms

conclusions about storms

The example above shows what one record would look like.

public void read()
{
    try
    {
        FileReader fr = new FileReader(file_path);
        BufferedReader br = new BufferedReader(fr);
        String s = "";
        // keep going untill there is no input left and then exit         
        while((s = br.readLine()) != null)
        { }
        fr.close();
    }
    catch (Exception e)
    {
        System.err.println("Error: read() " + e.getMessage());
    }
}

public static void main(String [] args)
{
    Reader reader = new ResultsReader("C:/data.txt");
    reader.read();
    String output = ((ResultsReader)reader).getInput();
    String str = "title<.>section1<.>section2<.>";
    String data[] = str.split("<.>");   
}

I am not sure how to store the data in separate ArrayLists so that they can be traversed.

amaidment · Accepted Answer · 2012-05-13 21:46:09Z

1

You cannot create arrays and put the data into them, because you don't know how large to create the arrays. So, use a list instead and then turn them into arrays after you have finished reading the file:

List tilesList = new ArrayList<String>();
// etc.

FileReader fr = new FileReader(file_path);
BufferedReader br = new BufferedReader(fr);
String s = null // I think this should be null, so that if there are no lines, 
                // you don't have problems with str.split();
while((s = br.readLine()) != null) {
  String[] line = str.split("<.>");
  tilesList.add(line[1]);
  // etc.
}
fr.close();

String[] tiles = tilesList.toArray(new String[tilesList.size()]);
// etc.

answered May 13, 2012 at 21:46

amaidment

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1 Comment

al23dev Over a year ago

i should have added arraylist my mistake

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