Package com.puppycrawl.tools.checkstyle.checks

Class UncommentedMainCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public class UncommentedMainCheck
extends AbstractCheck

    Detects uncommented main methods.

    Rationale: A main method is often used for debugging purposes. When debugging is finished, developers often forget to remove the method, which changes the API and increases the size of the resulting class or JAR file. With the exception of the real program entry points, all main methods should be removed or commented out of the sources.

    • Property excludedClasses - Specify pattern for qualified names of classes which are allowed to have a main method. Type is java.util.regex.Pattern. Default value is "^$".

    To configure the check: 

     <module name="UncommentedMain"/>

    Example:

     public class Game {
    public static void main(String... args){}   // violation
 }

 public class Main {
    public static void main(String[] args){}   // violation
 }

 public class Launch {
    //public static void main(String[] args){} // OK
 }

 public class Start {
    public void main(){}                       // OK
 }

 public record MyRecord1 {
    public void main(){}                       // violation
 }

 public record MyRecord2 {
    //public void main(){}                       // OK
 }

    To configure the check to allow the main method for all classes with "Main" name: 

     <module name="UncommentedMain">
   <property name="excludedClasses" value="\.Main$"/>
 </module>

    Example:

     public class Game {
    public static void main(String... args){}   // violation
 }

 public class Main {
    public static void main(String[] args){}   // OK
 }

 public class Launch {
    //public static void main(String[] args){} // OK
 }

 public class Start {
    public void main(){}                       // OK
 }

 public record MyRecord1 {
    public void main(){}                       // OK
 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • uncommented.main
    Since:
    3.2

    • Field Detail

      • MSG_KEY

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

    • Constructor Detail

      • UncommentedMainCheck

        public UncommentedMainCheck()

    • Method Detail

      • setExcludedClasses

        public void setExcludedClasses​(java.util.regex.Pattern excludedClasses)
        Setter to specify pattern for qualified names of classes which are allowed to have a main method.
        Parameters:
        excludedClasses - a pattern

      • 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:
        TokenTypes

      • 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:
        TokenTypes

      • 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:
        TokenTypes

      • beginTree

        public void beginTree​(DetailAST rootAST)
        Description copied from class: AbstractCheck
        Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
        Overrides:
        beginTree in class AbstractCheck
        Parameters:
        rootAST - the root of the tree

      • leaveToken

        public void leaveToken​(DetailAST ast)
        Description copied from class: AbstractCheck
        Called after all the child nodes have been process.
        Overrides:
        leaveToken in class AbstractCheck
        Parameters:
        ast - the token leaving