resources.report.rules.pmd.PositionLiteralsFirstInComparisons.html Maven / Gradle / Ivy

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PositionLiteralsFirstInComparisons


PositionLiteralsFirstInComparisons
Position literals first in String comparisons - that way if the String is null you won't get a NullPointerException, it'll just return false.
  
		
		
		    
    			This rule is defined by the following XPath expression:
    			
    			
                  
//PrimaryExpression[
        PrimaryPrefix[Name
                [
	(ends-with(@Image, '.equals'))
                ]
        ]
        [
                   (../PrimarySuffix/Arguments/ArgumentList/Expression/PrimaryExpression/PrimaryPrefix/Literal)
	and
	( count(../PrimarySuffix/Arguments/ArgumentList/Expression) = 1 )
        ]
]
[not(ancestor::Expression/ConditionalAndExpression//EqualityExpression[@Image='!=']//NullLiteral)]
[not(ancestor::Expression/ConditionalOrExpression//EqualityExpression[@Image='==']//NullLiteral)]

          
          
  
		    
		    
	    
	    
        
        
        Example:
            
                    

class Foo {
 boolean bar(String x) {
  return x.equals("2"); // should be "2".equals(x)
 }
}