Java parsing many instances of substring from String

I am trying to write a small java program that will accept a file (using Scanner开发者_运维问答 class), return the file as a String, and then search that string for any instance of a substring starting with "Email:" and ending with ".edu". There will be many instances of this substring, each of which I want to parse out into an array or a new file.

I know how to find a substring, but I do not know how to A) search for all instances of the substring and B) specify the start AND finish of the substring.

Can someone help me with this logic?

Thanks!

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You could use indexOf(). I think you can tell it where to search from too. So to find your instances of "Email:":

while(index < input.size()){
  substringLocation = input.indexOf("Email:", index);
  // do something with substring
  index = substringLocation;
}

---

This sounds like a case for regular expressions to me:

import java.util.regex.*;

public class Test
{
    private static final Pattern EMAIL_PATTERN = Pattern.compile
        ("Email:(.*?\\.edu)");

    public static void main(String[] args)
    {
        String testString = "FooEmail:jjj@xyz.edu Bar Email:mmm@abc.edu Baz";

        printEmails(testString);
    }

    public static void printEmails(String input)
    {
        Matcher matcher = EMAIL_PATTERN.matcher(input);
        while (matcher.find())
        {
            System.out.println(matcher.group(1));
        }
    }
}

Note that you'll get strange results if you have any non .edu emails in there... for example, if you have "Email: foo@bar.com Email: a@b.edu" you'd end up with a match of "foo@bar.com Email: a@b.edu".

---

private static final Pattern EMAIL_PATTERN = Pattern.compile
    ("Email:(.*?\\.[a-z]*?[\\.[a-z]]*)"); 

Will solve the problem and itt will work for any email pattern such as abc.co.in xyz.com or test.fileserver.abc.co.bz domains.