Package com.puppycrawl.tools.checkstyle.checks.coding

Class ExplicitInitializationCheck

java.lang.Object
com.puppycrawl.tools.checkstyle.AbstractAutomaticBean
com.puppycrawl.tools.checkstyle.api.AbstractViolationReporter
com.puppycrawl.tools.checkstyle.api.AbstractCheck
com.puppycrawl.tools.checkstyle.checks.coding.ExplicitInitializationCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class ExplicitInitializationCheck extends AbstractCheck
Checks if any class or object member is explicitly initialized to default for its type value (null for object references, zero for numeric types and char and false for boolean.

Rationale: Each instance variable gets initialized twice, to the same value. Java initializes each instance variable to its default value (0 or null) before performing any initialization specified in the code. So there is a minor inefficiency.

  • Property onlyObjectReferences - Control whether only explicit initializations made to null for objects should be checked. Type is boolean. Default value is false.

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • explicit.init
Since:
3.2

  • 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:

    • onlyObjectReferences

      private boolean onlyObjectReferences
      Control whether only explicit initializations made to null for objects should be checked.

  • Constructor Details

  • Method Details

    • getDefaultTokens

      public final 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:

    • getRequiredTokens

      public final 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:

    • getAcceptableTokens

      public final 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:

    • setOnlyObjectReferences

      public void setOnlyObjectReferences(boolean onlyObjectReferences)
      Setter to control whether only explicit initializations made to null for objects should be checked.
      Parameters:
      onlyObjectReferences - whether only explicit initialization made to null should be checked
      Since:
      7.8

    • 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

    • validateNonObjects

      private void validateNonObjects(DetailAST ast)
      Checks for explicit initializations made to 'false', '0' and '\0'.
      Parameters:
      ast - token being checked for explicit initializations

    • isZeroChar

      private static boolean isZeroChar(DetailAST exprStart)
      Examine char literal for initializing to default value.
      Parameters:
      exprStart - expression
      Returns:
      true is literal is initialized by zero symbol

    • isSkipCase

      private static boolean isSkipCase(DetailAST ast)
      Checks for cases that should be skipped: no assignment, local variable, final variables.
      Parameters:
      ast - Variable def AST
      Returns:
      true is that is a case that need to be skipped.

    • isNumericType

      private static boolean isNumericType(int type)
      Determine if a given type is a numeric type.
      Parameters:
      type - code of the type for check.
      Returns:
      true if it's a numeric type.
      See Also:

    • isZero

      private static boolean isZero(DetailAST expr)
      Checks if given node contains numeric constant for zero.
      Parameters:
      expr - node to check.
      Returns:
      true if given node contains numeric constant for zero.