Java Reference
In-Depth Information
Character
Matches
Character
Matches
\d
any digit
any nondigit
\D
\w
any word character
\W
any nonword character
\s
any white-space character
\S
any non-whitespace
character
Fig. 14.19 | Predefined character classes.
Regular expressions are not limited to these predefined character classes. The expres-
sions employ various operators and other forms of notation to match complex patterns.
We examine several of these techniques in the application in Figs. 14.20 and 14.21, which
validates user input via regular expressions. [ Note: This application is not designed to match
all possible valid user input.]
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// Fig. 14.20: ValidateInput.java
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// Validating user information using regular expressions.
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public class ValidateInput
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{
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// validate first name
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public static boolean validateFirstName(String firstName)
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{
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return firstName.matches( "[A-Z][a-zA-Z]*" );
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}
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// validate last name
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public static boolean validateLastName(String lastName)
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{
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return lastName.matches( "[a-zA-z]+(['-][a-zA-Z]+)*" );
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}
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// validate address
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public static boolean validateAddress(String address)
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{
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return address.matches(
"\\d+\\s+([a-zA-Z]+|[a-zA-Z]+\\s[a-zA-Z]+)" );
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}
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// validate city
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public static boolean validateCity(String city)
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{
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return city.matches( "([a-zA-Z]+|[a-zA-Z]+\\s[a-zA-Z]+)" );
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}
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// validate state
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public static boolean validateState(String state)
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{
Fig. 14.20 | Validating user information using regular expressions. (Part 1 of 2.)
 
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