I have a string that contains a few numbers (usually a date) and separators. The separators can either be "," or "." - or example 01.05,2000.5000
....now I need to separate those numbers and put into an array but I'm not sure how to do that (the separating part). Also, I need to check that the string is valid - it cannot be 01.,05.
I'm not asking for anyone to solve the thing for me (but if someone wants I appreciated it), just point me in the right direction :)
This is a way of doing it with StringTokenizer class, just iterate the tokens and if the obtained token is empty then you have a invalid String, also, convert the tokens to integers by the parseInt method to check if they are valid integer numbers:
import java.util.*;
public class t {
public static void main(String... args) {
String line = "01.05,2000.5000";
StringTokenizer strTok = new StringTokenizer(line, ",.");
List<Integer> values = new ArrayList<Integer>();
while (strTok.hasMoreTokens()) {
String s = strTok.nextToken();
if (s.length() == 0) {
// Found a repeated separator, String is not valid, do something about it
}
try {
int value = Integer.parseInt(s, 10);
values.add(value);
} catch(NumberFormatException e) {
// Number not valid, do something about it or continue the parsing
}
}
// At the end, get an array from the ArrayList
Integer[] arrayOfValues = values.toArray(new Integer[values.size()]);
for (Integer i : arrayOfValues) {
System.out.println(i);
}
}
}
Iterate through an String#split(regex) generated array and check each value to make sure your source String is "valid".
In:
String src = "01.05,2000.5000";
String[] numbers = src.split("[.,]");
numbers here will be an array of Strings, like {"01", "05", "2000", "5000"}. Each value is a number.
Now iterate over numbers. If you find a index that is not a number (it's a number when numbers[i].matches("\\d+") is true), then your src is invalid.
If possible, I would use guava String splitter for that. It is much more reliable, predictable and flexible than String#split. You can tell it exactly what to expect, what to omit, and so on.
For an example usage, and a small rant on how stupid javas split sometimes behaves, have a look here: http://code.google.com/p/guava-libraries/wiki/StringsExplained#Splitter
Use regex to group and match the input
String s = "01.05,2000.5000";
Pattern pattern = Pattern.compile("(\\d{2})[.,](\\d{2})[.,](\\d{4})[.,](\\d{4})");
Matcher m = pattern.matcher(s);
if(m.matches()) {
String[] matches = { m.group(1),m.group(2), m.group(3),m.group(4) };
for(String match : matches) {
System.out.println(match);
}
} else {
System.err.println("Mismatch");
}
Try this:
String str = "01.05,2000.5000";
str = str.replace(".",",");
int number = StringUtils.countMatches(str, ",");
String[] arrayStr = new String[number+1];
arrayStr = str.split(",");
StringUtils is from Apache Commons >> http://commons.apache.org/proper/commons-lang/
To validate:
if (input.matches("^(?!.*[.,]{2})[\\d.,]+))
This regex checks that:
To split:
String[] numbers = input.split("[.,]");
numbers be an Array as split function returns an Array ?
In order to separate the string, use split(), the argument of the method is the delimiter
array = string.split("separator");
String#split(...)allows for regular expressions to be used as the delimiter. I'd experiment with that. All you need is something very simple.