Class TypeNameCheck

Checks that type names conform to a specified pattern.

• Property format - Specifies valid identifiers. Type is java.util.regex.Pattern. Default value is "^[A-Z][a-zA-Z0-9]*$".
• Property applyToPublic - Controls whether to apply the check to public member. Type is boolean. Default value is true.
• Property applyToProtected - Controls whether to apply the check to protected member. Type is boolean. Default value is true.
• Property applyToPackage - Controls whether to apply the check to package-private member. Type is boolean. Default value is true.
• Property applyToPrivate - Controls whether to apply the check to private member. Type is boolean. Default value is true.
• Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: CLASS_DEF, INTERFACE_DEF, ENUM_DEF, ANNOTATION_DEF, RECORD_DEF.

To configure the check:

 <module name="TypeName"/>
 

Code Example:

 public interface FirstName {} // OK
 protected class SecondName {} // OK
 enum Third_Name {} // violation, name 'Third_Name' must match pattern '^[A-Z][a-zA-Z0-9]*$'
 private class FourthName_ {} // violation, name 'FourthName_'
                              // must match pattern '^[A-Z][a-zA-Z0-9]*$'
 

An example of how to configure the check for names that begin with a lower case letter, followed by letters, digits, and underscores. Also, suppress the check from being applied to protected and private type:

 <module name="TypeName">
   <property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/>
   <property name="applyToProtected" value="false"/>
   <property name="applyToPrivate" value="false"/>
 </module>
 

Code Example:

 public interface firstName {} // OK
 public class SecondName {} // violation, name 'SecondName'
                            // must match pattern '^[a-z](_?[a-zA-Z0-9]+)*$'
 protected class ThirdName {} // OK
 private class FourthName {} // OK
 

The following configuration element ensures that interface names begin with "I_", followed by letters and digits:

 <module name="TypeName">
   <property name="format"
     value="^I_[a-zA-Z0-9]*$"/>
   <property name="tokens"
     value="INTERFACE_DEF"/>
 </module>
 

Code Example:

 public interface I_firstName {} // OK
 interface SecondName {} // violation, name 'SecondName'
                         // must match pattern '^I_[a-zA-Z0-9]*$'
 

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

• name.invalidPattern