I've a txt file composed by two columns like this:
Name1 _ Opt1
Name2 _ Opt2
Name3 _ Opt3
In each row there's a name, a tab delimiter, a _ and then another name; there are really many rows (about 150000) and i'm not even sure which one is the best constructor to use, i'm thinking about a two dimensional array but it could be also something else if it's a better choice. For me it's important that i can access to the elements with something like this a[x][y]. I've done this but i just know how to count the number of the lines or how to put each lines in a different position of an array. Here's the code:
int countLine = 0;
BufferedReader reader = new BufferedReader(new FileReader(filename));
while (true) {
String line = reader.readLine();
if (line == null) {
reader.close();
break;
} else {
countLine++;
}
}
Since you don't know the number of lines ahead of time, I would use an ArrayList
instead of an array. The splitting of lines into String values can easily be done with a regular expression.
Pattern pattern = Pattern.compile("(.*)\t_\t(.*)");
List<String[]> list = new ArrayList<>();
int countLine = 0;
BufferedReader reader = new BufferedReader(new FileReader(filename));
while (true) {
String line = reader.readLine();
if (line == null) {
reader.close();
break;
} else {
Matcher matcher = pattern.matcher(line);
if (matcher.matches()) {
list.add(new String[] { matcher.group(1), matcher.group(2) });
}
countLine++;
}