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

Class OperatorWrapCheck

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

    Checks the policy on how to wrap lines on operators.

    To configure the check: 

     <module name="OperatorWrap"/>

    Example: 

     class Test {
     public static void main(String[] args) {
         String s = "Hello" +
         "World"; // violation, '+' should be on new line

         if (10 ==
                 20) { // violation, '==' should be on new line.
         // body
         }
         if (10
                 ==
                 20) { // ok
         // body
         }

         int c = 10 /
                 5; // violation, '/' should be on new line.

         int d = c
                 + 10; // ok
     }

 }

    To configure the check for assignment operators at the end of a line: 

     <module name="OperatorWrap">
   <property name="tokens"
     value="ASSIGN,DIV_ASSIGN,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,MOD_ASSIGN,
            SR_ASSIGN,BSR_ASSIGN,SL_ASSIGN,BXOR_ASSIGN,BOR_ASSIGN,BAND_ASSIGN"/>
   <property name="option" value="eol"/>
 </module>

    Example: 

     class Test {
     public static void main(String[] args) {
             int b
                     = 10; // violation, '=' should be on previous line
             int c =
                     10; // ok
             b
                     += 10; // violation, '+=' should be on previous line
             b +=
                     10; // ok
             c
                     *= 10; // violation, '*=' should be on previous line
             c *=
                     10; // ok
             c
                     -= 5; // violation, '-=' should be on previous line
             c -=
                     5; // ok
             c
                     /= 2; // violation, '/=' should be on previous line
             c
                     %= 1; // violation, '%=' should be on previous line
             c
                     >>= 1; // violation, '>>=' should be on previous line
             c
                 >>>= 1; // violation, '>>>=' should be on previous line
         }
         public void myFunction() {
             c
                     ^= 1; // violation, '^=' should be on previous line
             c
                     |= 1; // violation, '|=' should be on previous line
             c
                     &=1 ; // violation, '&=' should be on previous line
             c
                     <<= 1; // violation, '<<=' should be on previous line
     }
 }

    Parent is com.puppycrawl.tools.checkstyle.TreeWalker

    Violation Message Keys:

    • line.new
    • line.previous
    Since:
    3.0

    • Field Detail

      • MSG_LINE_NEW

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

      • MSG_LINE_PREVIOUS

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

    • Constructor Detail

      • OperatorWrapCheck

        public OperatorWrapCheck()

    • Method Detail

      • setOption

        public void setOption​(java.lang.String optionStr)
        Setter to specify policy on how to wrap lines.
        Parameters:
        optionStr - string to decode option from
        Throws:
        java.lang.IllegalArgumentException - if unable to decode

      • 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