Class FallThroughCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable

    public class FallThroughCheck
    extends AbstractCheck
    Checks for fall through in switch statements Finds locations where a case contains Java code - but lacks a break, return, throw or continue statement.

    The check honors special comments to suppress warnings about the fall through. By default the comments "fallthru", "fall through", "falls through" and "fallthrough" are recognized.

    The following fragment of code will NOT trigger the check, because of the comment "fallthru" and absence of any Java code in case 5.

     case 3:
         x = 2;
         // fallthru
     case 4:
     case 5:
     case 6:
         break;
     

    The recognized relief comment can be configured with the property reliefPattern. Default value of this regular expression is "fallthru|fall through|fallthrough|falls through".

    An example of how to configure the check is:

     <module name="FallThrough">
         <property name="reliefPattern"
                      value="Fall Through"/>
     </module>
     
    • Field Detail

      • MSG_FALL_THROUGH

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

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

      • FallThroughCheck

        public FallThroughCheck()
    • Method Detail

      • 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
      • 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
      • setReliefPattern

        public void setReliefPattern​(java.util.regex.Pattern pattern)
        Set the relief pattern.
        Parameters:
        pattern - The regular expression pattern.
      • setCheckLastCaseGroup

        public void setCheckLastCaseGroup​(boolean value)
        Configures whether we need to check last case group or not.
        Parameters:
        value - new value of the property.