Buffer string to array list, and split

Question

I am buffering a text file of into 'arraylist lines' i then need to split each line into a new arrayList parts, so that i can find information from each line and add the data to a model i have built, the reason i am using arrayLists is because of there expandable properties, meaning i wont need to worry about the size of either the line or the text file.

the code is below:

    try(BufferedReader buffer = 
            new BufferedReader(new FileReader("src/Sample.txt")))
    {
        String currentLine;
        ArrayList<String> lines = new ArrayList<String>();
        ArrayList<String> parts = new ArrayList<String>();
        //ListIterator<String> lineItr = lines.listIterator();

        while((currentLine = buffer.readLine()) != null)
        {
            lines.add(currentLine);

            for(String line : lines)
            {
                parts.addAll(line.split("\\s+"));

            }


            //lineItr.next();
            //lineItr.set(currentLine);

            //System.out.println(lineItr.next());
        }
    }
    catch(IOException e)
    {
        e.printStackTrace();
    }

}

i am having my troubles with parts.addAll(line.split("\s+"); i do not understand why the statement does not iterate through lines, splitting and adding each part of the string to the parts array list, am i misunderstanding something here?

thanks Babble

Rahul · Accepted Answer · 2013-05-03 12:29:28Z

3

list.addAll() accepts a java.util.Collection where as str.split returns you an array is not a collection. Hence you can not add it directly to a list. You need to convert into a list first.

for(String line : lines)
{
   parts.addAll(Arrays.asList(line.split("\\s+"));
}

answered May 3, 2013 at 12:29

Rahul

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Comments

Achintya Jha · Accepted Answer · 2013-05-03 12:32:38Z

2

String.split() returns Array of String . So you have to use Arrays.asList() to convert it into list .

parts.addAll(line.split("\\s+"));

Above line should be:

parts.addAll(Arrays.asList(line.split("\\s+")));

Or :

Collections.addAll(parts, line.split("\\s+"));

edited May 3, 2013 at 12:32

answered May 3, 2013 at 12:27

Achintya Jha

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3 Comments

Babbleshack Over a year ago

Thanks for answer an explanation :), what is collections?

Achintya Jha Over a year ago

@Babbleshack See this link to understand better.

Achintya Jha Over a year ago

@Babbleshack No. Click on "this" on my previous comment.

NPKR · Accepted Answer · 2013-05-03 12:28:59Z

2

try this

parts.addAll(Arrays.asList(line.split("\\s+")));

answered May 3, 2013 at 12:28

NPKR

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Comments

Evgeniy Dorofeev · Accepted Answer · 2013-05-03 12:27:39Z

1

List.addAll accepts a Collection but line.split("\\s+") returns String[]. You can do it this way

parts.addAll(Arrays.asList(line.split("\\s+")));

answered May 3, 2013 at 12:27

Evgeniy Dorofeev

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Comments

Szocske · Accepted Answer · 2013-05-03 12:49:25Z

0

Every time a new line arrives, you append the whole thing all over again. Drop the inner "for" loop, and just split currentLine instead.

EDIT based on comment:

The Java Way would be implementing the year and month objects as containers. The simpler alternative is using string-keyed maps.

edited May 3, 2013 at 12:49

answered May 3, 2013 at 12:31

Szocske

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5 Comments

Babbleshack Over a year ago

That's a good point, problem is i want to incorporate a second data set, and if that data set contains a different layout, then i wont be able to handle it.

Szocske Over a year ago

I don't think I understand :-)

Babbleshack Over a year ago

haha, okay well, i have a data set. which is a text file. each line has a year, then a month, then a collections of days, i want to load that data into an arraylist of year obj, which contains an array list of month obj, which in turn contains a list of days. If the format of the data file change i would have a problem loading the data in if i didn't use the lines list.

Szocske Over a year ago

Oh, that's a completely different question then :-) I'll edit my answer.

Babbleshack Over a year ago

ill look into string-keyed maps when i get back from my lecture

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