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

Class WhitespaceAfterCheck

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

    Checks that a token is followed by whitespace, with the exception that it does not check for whitespace after the semicolon of an empty for iterator. Use Check EmptyForIteratorPad to validate empty for iterators.

    To configure the check: 

     <module name="WhitespaceAfter"/>

    Example:

      public void myTest() {
      if (foo) {              // OK
              //...
      } else if(bar) {        // violation
              //...
      }

      testMethod(foo, bar);   // OK
      testMethod(foo,bar);    // violation

      for (;;){}               // OK
      for(;;){}                // violation, space after 'for' is required

      try (InputStream ignored = System.in) {} // OK
      try(InputStream ignored = System.in) {} // violation ''try' is not followed by whitespace'

      try {} catch (Exception e){} // OK
      try{} catch (Exception e){} // violation ''try' is not followed by whitespace'

      try {} finally {} // OK
      try {} finally{} // violation ''finally' is not followed by whitespace'

      try {} catch (Error e){} finally {} // OK
      try {} catch (Error e){} finally{} // violation ''finally' is not followed by whitespace'

      try {} catch (Exception e){} // OK
      try {} catch(Exception e){} // violation ''catch' is not followed by whitespace'

      synchronized (this) { } // OK
      synchronized(this) { } // violation ''synchronized' is not followed by whitespace'
  }
  public String testOne() {
      return ("a" + "b"); // OK
  }
  public String testTwo() {
      return("a" + "b"); // violation 'return' is not followed by whitespace'
  }
  public static void main(String[] args) {
    int a = switch (args[0]) {
      case "got":
        yield (1); // OK
      case "my":
        yield(3); // violation ''yield' is not followed by whitespace'
      default:
        yield 2;
    };
  }

    To configure the check for whitespace only after COMMA and SEMI tokens: 

     <module name="WhitespaceAfter">
   <property name="tokens" value="COMMA, SEMI"/>
 </module>

    Example:

         public void myTest() {
         int a; int b;           // OK
         int a;int b;            // violation

         testMethod(foo, bar);   // OK
         testMethod(foo,bar);    // violation

         for(;;) {} // OK
     }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • ws.notFollowed
    • ws.typeCast
    Since:
    3.0

    • Method Detail

      • 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

      • isFollowedByWhitespace

        private static boolean isFollowedByWhitespace​(DetailAST targetAST,
                                              int... line)
        Checks whether token is followed by a whitespace.
        Parameters:
        targetAST - Ast token.
        line - Unicode code points array of line associated with the ast token.
        Returns:
        true if ast token is followed by a whitespace.