Looking to parse the following text file:
Sample text file:<2008-10-07>text entered by user<Ted Parlor><2008-11-26>additional text entered by user<Ted Parlor>
I would like to parse the above text so that I can have three variables:
v1 = 2008-10-07
v2 = text entered by user
v3 = Ted Parlor
v1 = 2008-11-26
v2 = additional text entered by user
v3 = Ted Parlor
I attempted to use scanner and useDelimiter, however, I'm having issue on how t开发者_如何转开发o set this up to have the results as stated above. Here's my first attempt:
import java.io.*;
import java.util.Scanner;
public class ScanNotes {
public static void main(String[] args) throws IOException {
Scanner s = null;
try {
//String regex = "(?<=\\<)([^\\>>*)(?=\\>)";
s = new Scanner(new BufferedReader(new FileReader("cur_notes.txt")));
s.useDelimiter("[<]+");
while (s.hasNext()) {
String v1 = s.next();
String v2= s.next();
System.out.println("v1= " + v1 + " v2=" + v2);
}
} finally {
if (s != null) {
s.close();
}
}
}
}
The results is as follows:
v1= 2008-10-07>text entered by user v2=Ted Parlor>
What I desire is:
v1= 2008-10-07 v2=text entered by user v3=Ted Parlor
v1= 2008-11-26 v2=additional text entered by user v3=Ted Parlor
Any help that would allow me to extract all three strings separately would be greatly appreciated.
You can use \s*[<>]\s*
as delimiter. That is, any of <
or >
, with any preceding and following whitespaces.
For this to work, there must not be any <
or >
in the input other than the ones used to mark the date and user fields in the input (i.e. no I <3 U!!
in the message).
This delimiter allows empty string parts in an entry, but it also leaves empty string tokens between any two entries, so they must be discarded manually.
import java.util.Scanner;
public class UseDelim {
public static void main(String[] args) {
String content = " <2008-10-07>text entered by user <Ted Parlor>"
+ " <2008-11-26> additional text entered by user <Ted Parlor>"
+ " <2008-11-28><Parlor Ted> ";
Scanner sc = new Scanner(content).useDelimiter("\\s*[<>]\\s*");
while (sc.hasNext()) {
System.out.printf("[%s|%s|%s]%n",
sc.next(), sc.next(), sc.next());
// if there's a next entry, discard the empty string token
if (sc.hasNext()) sc.next();
}
}
}
This prints:
[2008-10-07|text entered by user|Ted Parlor]
[2008-11-26|additional text entered by user|Ted Parlor]
[2008-11-28||Parlor Ted]
See also
- regular-expressions.info/Character classes
- regular-expressions.info/Repetition
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