Class MultipleVariableDeclarationsCheck

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.coding.MultipleVariableDeclarationsCheck
All Implemented Interfaces:
Configurable, Contextualizable
public class MultipleVariableDeclarationsCheck extends AbstractCheck

Checks that each variable declaration is in its own statement and on its own line.

Rationale: the Java code conventions chapter 6.1 recommends that declarations should be one per line/statement.

To configure the check: 

<module name="MultipleVariableDeclarations"/>

Example: 

public class Test {
  public void myTest() {
    int mid;
    int high;
    // ...

    int lower, higher; // violation
    // ...

    int value,
        index; // violation
    // ...

    int place = mid, number = high;  // violation
  }
}

Parent is com.puppycrawl.tools.checkstyle.TreeWalker

Violation Message Keys:

  • multiple.variable.declarations
  • multiple.variable.declarations.comma
Since:
3.4

  • Field Details

    • MSG_MULTIPLE

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

    • MSG_MULTIPLE_COMMA

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

  • Constructor Details

    • MultipleVariableDeclarationsCheck

      public MultipleVariableDeclarationsCheck()

  • Method Details

    • 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:

    • 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:

    • 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

    • getLastNode

      private static DetailAST getLastNode(DetailAST node)
      Finds sub-node for given node maximum (line, column) pair.
      Parameters:
      node - the root of tree for search.
      Returns:
      sub-node with maximum (line, column) pair.