Package com.puppycrawl.tools.checkstyle.checks.whitespace

Class ParenPadCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public class ParenPadCheck
extends AbstractParenPadCheck

    Checks the policy on the padding of parentheses; that is whether a space is required after a left parenthesis and before a right parenthesis, or such spaces are forbidden. No check occurs at the right parenthesis after an empty for iterator, at the left parenthesis before an empty for initialization, or at the right parenthesis of a try-with-resources resource specification where the last resource variable has a trailing semi-colon. Use Check EmptyForIteratorPad to validate empty for iterators and EmptyForInitializerPad to validate empty for initializers. Typecasts are also not checked, as there is TypecastParenPad to validate them.

    To configure the check: 

     <module name="ParenPad"/>

    Example: 

     class Foo {

   int n;

   public void fun() {  // OK
     bar( 1);  // violation, space after left parenthesis
   }

   public void bar(int k ) {  // violation, space before right parenthesis
     while (k > 0) {  // OK
     }

     Test obj = new Test(k);  // OK
   }

   public void fun2() {  // OK
     switch( n) {  // violation, space after left parenthesis
       case 2:
         bar(n);  // OK
       default:
         break;
     }
   }

 }

    To configure the check to require spaces for the parentheses of constructor, method, and super constructor calls: 

     <module name="ParenPad">
   <property name="tokens" value="LITERAL_FOR, LITERAL_CATCH,
     SUPER_CTOR_CALL"/>
   <property name="option" value="space"/>
 </module>

    Example: 

     class Foo {

   int x;

   public Foo(int n) {
   }

   public void fun() {
     try {
       System.out.println(x);
     } catch( IOException e) {  // violation, no space before right parenthesis
     } catch( Exception e ) {  // OK
     }

     for ( int i = 0; i < x; i++ ) {  // OK
     }
   }

 }

 class Bar extends Foo {

   public Bar() {
     super(1 );  // violation, no space after left parenthesis
   }

   public Bar(int k) {
     super( k ); // OK

     for ( int i = 0; i < k; i++) {  // violation, no space before right parenthesis
     }
   }

 }

    The following cases are not checked: 

     for ( ; i < j; i++, j--) // no check after left parenthesis
 for (Iterator it = xs.iterator(); it.hasNext(); ) // no check before right parenthesis
 try (Closeable resource = acquire(); ) // no check before right parenthesis

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • ws.followed
    • ws.notFollowed
    • ws.notPreceded
    • ws.preceded
    Since:
    3.0

    • Constructor Detail

      • ParenPadCheck

        public ParenPadCheck()
        Initializes and sorts acceptableTokens to make binary search over it possible.

    • 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

      • 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

      • 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