LocalFinalVariableName

Since Checkstyle 3.0

Description

Checks that local final variable names conform to a specified pattern. A catch parameter and resources in try statements are considered to be a local, final variables.

This check does not support final pattern variables. Instead, use PatternVariableName.

Properties

name	description	type	default value	since
format	Sets the pattern to match valid identifiers.	Pattern	`"^([a-z][a-zA-Z0-9]*\|_)$"`	3.0
tokens	tokens to check	subset of tokens VARIABLE_DEF , PARAMETER_DEF , RESOURCE .	VARIABLE_DEF , PARAMETER_DEF , RESOURCE .	3.0

Examples

To configure the check:


<module name="Checker">
  <module name="TreeWalker">
    <module name="LocalFinalVariableName">
       <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
    </module>
  </module>
</module>

Code Example:


class Example1{
  void MyMethod() {
    try {
      final int VAR1 = 5; // violation 'Name 'VAR1' must match pattern'
      final int var1 = 10;
    } catch (Exception ex) {
      final int VAR2 = 15; // violation 'Name 'VAR2' must match pattern'
      final int var2 = 20;
    }
  }
}

An example of how to configure the check for names that are only upper case letters and digits is:


<module name="Checker">
  <module name="TreeWalker">
    <module name="LocalFinalVariableName">
      <property name="format" value="^[A-Z][A-Z0-9]*$"/>
    </module>
  </module>
</module>

Code Example:


class Example2 {
  void MyMethod() {
    try {
      final int VAR1 = 5;
      final int var1 = 10; // violation 'Name 'var1' must match pattern'
    } catch (Exception ex) {
      final int VAR2 = 15;
      final int var2 = 20; // violation 'Name 'var2' must match pattern'
    }
  }
}

An example of how to configure the check for names of local final parameters and resources in try statements (without checks on variables):


<module name="Checker">
  <module name="TreeWalker">
    <module name="LocalFinalVariableName">
      <property name="format" value="^[A-Z][A-Z0-9]*$"/>
      <property name="tokens" value="PARAMETER_DEF,RESOURCE"/>
    </module>
  </module>
</module>

Code Example:


class Example3 {
  void MyMethod() {
    // violation below 'Name 'scanner' must match pattern'
    try(Scanner scanner = new Scanner(System.in)) {

      final int VAR1 = 5;
      final int var1 = 10;
    } catch (final Exception ex) { // violation 'Name 'ex' must match pattern'

      final int VAR2 = 15;
      final int var2 = 20;
    }
  }
}

Example of Usage

Violation Messages

name.invalidPattern

All messages can be customized if the default message doesn't suit you. Please see the documentation to learn how to.

Package

com.puppycrawl.tools.checkstyle.checks.naming

Parent Module

TreeWalker