You can use simple String.matches(regex) to test any string against a regex pattern instead of using Pattern and Matcher classes.
Sample:
boolean isValid = phoneString.matches(regexPattern);
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Here is the regex pattern as per your input string:
\+\d(-\d{3}){2}-\d{4}
Online demo
Better use Spring validation annotation for validation.
Example
Answer from Braj on Stack OverflowYou can use simple String.matches(regex) to test any string against a regex pattern instead of using Pattern and Matcher classes.
Sample:
boolean isValid = phoneString.matches(regexPattern);
Find more examples
Here is the regex pattern as per your input string:
\+\d(-\d{3}){2}-\d{4}
Online demo
Better use Spring validation annotation for validation.
Example
// The Regex not validate mobile number, which is in internation format.
// The Following code work for me.
// I have use libphonenumber library to validate Number from below link.
// http://repo1.maven.org/maven2/com/googlecode/libphonenumber/libphonenumber/8.0.1/
// https://github.com/googlei18n/libphonenumber
// Here, is my source code.
public boolean isMobileNumberValid(String phoneNumber)
{
boolean isValid = false;
// Use the libphonenumber library to validate Number
PhoneNumberUtil phoneUtil = PhoneNumberUtil.getInstance();
Phonenumber.PhoneNumber swissNumberProto =null ;
try {
swissNumberProto = phoneUtil.parse(phoneNumber, "CH");
} catch (NumberParseException e) {
System.err.println("NumberParseException was thrown: " + e.toString());
}
if(phoneUtil.isValidNumber(swissNumberProto))
{
isValid = true;
}
// The Library failed to validate number if it contains - sign
// thus use regex to validate Mobile Number.
String regex = "[0-9*#+() -]*";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(phoneNumber);
if (matcher.matches()) {
isValid = true;
}
return isValid;
}
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A regex to match your format:
(456)123-1234 (starting with only 4,5 or 6)
Would be:
^\([4-6]{1}[0-9]{2}\)[0-9]{3}-[0-9]{4}$
Example:
http://regex101.com/r/pZ7aL4
If you wanted to allow to an optional space after the closing parenthesis, ie:
(456) 123-1234
You would modify regex slightly like this:
^\([4-6]{1}[0-9]{2}\)\s?[0-9]{3}-[0-9]{4}$
String sPhoneNumber = "456-8889999";
Pattern pattern = Pattern.compile("\\([4-6]{1}[0-9]{2}\\) [0-9]{3}\\-[0-9]{4}$");
Matcher matcher = pattern.matcher(sPhoneNumber);
if (matcher.matches()) {
System.out.println("Phone Number Valid");
}
else
{
System.out.println("Phone Number must be in the form XXX-XXXXXXX");
}
If this is not homework, is there a reason you're avoiding regular expressions?
Here are some useful ones: http://regexlib.com/DisplayPatterns.aspx?cattabindex=6&categoryId=7
More generally, your code doesn't seem to validate that you have a phone number, it seems to merely validate that your strings consists only of digits. You're also not allowing any special characters right now.
Asides from the regex suggestion (which is a good one), it would seem to make more sense to deal with arrays of characters rather than single-char Strings.
In particular, the split("") call (shudder) could/should be replaced by toCharArray(). This lets you iterate over each individual character, which more clearly indicates your intent, is less prone to bugs as you know you're treating each character at once, and is more efficient*. Likewise your valid character sets should also be characters.
Your logic is pretty strangely expressed; you're not even referencing the specialChars set at all, and the looping logic once you've found a match seems odd. I think this is your bug; the matching seems to be the wrong way round in that if the character matches the first valid char, you set flag to false and continue round the current loop; so it will definitely not match the next valid char and hence you break out of the loop with a true flag. Always.
I would have thought something like this would be more intuitive:
private static final Set<Character> VALID_CHARS = ...;
public boolean isValidPhoneNumber(String number)
{
for (char c : number,toCharArray())
{
if (!VALID_CHARS.contains(c))
{
return false;
}
}
// All characters were valid
return true;
}
This doesn't take sequences into account (e.g. the strings "--------** " and "1" would be valid because all individual characters are valid) but then neither does your original code. A regex is better because it lets you specify the pattern, I supply the above snippet as an example of a clearer way of iterating through the characters.
*Yes, premature optimization is the root of all evil, but when better, cleaner code also happens to be faster that's an extra win for free.