Best way to read strings of characters separated by spaces in files

Question

so I'm working on a project where I'm trying to read thousands of lines from a text file in this format:

[email protected]     1209381231
[email protected]     1241231231
[email protected]     1231585849
[email protected]     2132389558
...

etc. etc. ....

Now, I want to read each email address into a string and completely ignore the numbers that comes after it, they aren't important to me. The numbers are separated from the email addressed by spaces.

So, what would be the best way to read each email address into their own string?

This looks like a job for [Scanner](http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html). — Jeff Bowman, Jun 13 '14 at 23:13
@shmosel Snide comments don't help anyone. Find one and flag this. — Anubian Noob, Jun 13 '14 at 23:14
possible duplicate of [What is simplest way to read a file into String?](http://stackoverflow.com/questions/3402735/what-is-simplest-way-to-read-a-file-into-string) — Rots, Jun 13 '14 at 23:18

score 0 · Answer 1 · answered Jun 13 '14 at 23:17

Look at the split() method. You specify a character and it splits the string based on that character. The parts of the string which were delimited by the character then get put into an array, which the method returns to you.

Then, assuming that there are no space characters before the email address starts, you can take the 0th element of the array and do with it what you like. Put it into a List, stream the list into a file, whatever.

score 0 · Answer 2 · answered Jun 13 '14 at 23:23

0

Use the split() method! It is definitely the best way of doing it! Other ways can be harder or take up more performance!

String[] strings = myString.split(" ");

answered Jun 13 '14 at 23:23

Victor2748

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Federico Piazza · Answer 3 · 2014-06-13T23:46:25.423

0

You can use:

String str = "HERE YOUR CONTENT";
String[] mailArray = str.split("\\s+\\d+");

If you print mailArray it will contain:

mailArray => 
(
    [email protected],
    [email protected],
    [email protected],
    [email protected]
)

edited Jun 13 '14 at 23:46

answered Jun 13 '14 at 23:27

Federico Piazza

30,085
15
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123

score 0 · Answer 4 · answered Jun 14 '14 at 04:53

You can try using java scanner class

String str = "name of your text file"
Scanner scan = new Scanner(new File(str));

ArrayList<String> emails = new ArrayList<String>();

Pattern pattern = //some email regex
String tmp = ""
while(tmp = scan.next(pattern)){

emails.add(tmp);

}

Best way to read strings of characters separated by spaces in files

4 Answers4