Package com.puppycrawl.tools.checkstyle.checks.sizes

Class MethodLengthCheck

java.lang.Object
com.puppycrawl.tools.checkstyle.api.AutomaticBean
com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
com.puppycrawl.tools.checkstyle.api.AbstractCheck
com.puppycrawl.tools.checkstyle.checks.sizes.MethodLengthCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class MethodLengthCheck extends AbstractCheck

Checks for long methods and constructors.

Rationale: If a method becomes very long it is hard to understand. Therefore long methods should usually be refactored into several individual methods that focus on a specific task.

  • Property max - Specify the maximum number of lines allowed. Type is int. Default value is 150.
  • Property countEmpty - Control whether to count empty lines and single line comments of the form //. Type is boolean. Default value is true.
  • Property tokens - tokens to check Type is java.lang.String[]. Validation type is tokenSet. Default value is: METHOD_DEF, CTOR_DEF, COMPACT_CTOR_DEF.

To configure the check: 

 <module name="MethodLength"/>

To configure the check so that it accepts methods with at most 60 lines: 

 <module name="MethodLength">
   <property name="tokens" value="METHOD_DEF"/>
   <property name="max" value="60"/>
 </module>

To configure the check so that it accepts methods with at most 60 lines, not counting empty lines and single line comments: 

 <module name="MethodLength">
   <property name="tokens" value="METHOD_DEF"/>
   <property name="max" value="60"/>
   <property name="countEmpty" value="false"/>
 </module>

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • maxLen.method
Since:
3.0

  • Field Details

    • MSG_KEY

      public static final String MSG_KEY
      A key is pointing to the warning message text in "messages.properties" file.
      See Also:

    • DEFAULT_MAX_LINES

      private static final int DEFAULT_MAX_LINES
      Default maximum number of lines.
      See Also:

    • countEmpty

      private boolean countEmpty
      Control whether to count empty lines and single line comments of the form //.

    • max

      private int max
      Specify the maximum number of lines allowed.

  • Constructor Details

    • MethodLengthCheck

      public MethodLengthCheck()

  • Method Details

    • getDefaultTokens

      public int[] getDefaultTokens()
      Description copied from class: AbstractCheck
      Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.
      Specified by:
      getDefaultTokens in class AbstractCheck
      Returns:
      the default tokens
      See Also:

    • getAcceptableTokens

      public int[] getAcceptableTokens()
      Description copied from class: AbstractCheck
      The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.
      Specified by:
      getAcceptableTokens in class AbstractCheck
      Returns:
      the token set this check is designed for.
      See Also:

    • getRequiredTokens

      public int[] getRequiredTokens()
      Description copied from class: AbstractCheck
      The tokens that this check must be registered for.
      Specified by:
      getRequiredTokens in class AbstractCheck
      Returns:
      the token set this must be registered for.
      See Also:

    • visitToken

      public void visitToken(DetailAST ast)
      Description copied from class: AbstractCheck
      Called to process a token.
      Overrides:
      visitToken in class AbstractCheck
      Parameters:
      ast - the token to process

    • getLengthOfBlock

      private int getLengthOfBlock(DetailAST openingBrace, DetailAST closingBrace)
      Returns length of code only without comments and blank lines.
      Parameters:
      openingBrace - block opening brace
      closingBrace - block closing brace
      Returns:
      number of lines with code for current block

    • setMax

      public void setMax(int length)
      Setter to specify the maximum number of lines allowed.
      Parameters:
      length - the maximum length of a method.

    • setCountEmpty

      public void setCountEmpty(boolean countEmpty)
      Setter to control whether to count empty lines and single line comments of the form //.
      Parameters:
      countEmpty - whether to count empty and single line comments of the form //.