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

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CheckResultSet


CheckResultSet
Always check the return of one of the navigation method (next,previous,first,last) of a ResultSet. Indeed,
	            if the value return is 'false', the developer should deal with it !
            
        
		
		
		    
    			This rule is defined by the following XPath expression:
    			
    			
    		        	
//Type/ReferenceType/ClassOrInterfaceType[
        (@Image = 'ResultSet')
        and
        (../../../descendant::Name[ends-with(@Image,'executeQuery')])
        and
        (
	(not (contains(
                        (./ancestor::Block/descendant::WhileStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.next')
		)  ) )
	and ( not ( contains(
                        (./ancestor::Block/descendant::IfStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.next')
		) ) )
	and (not (contains(
                        (./ancestor::Block/descendant::WhileStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.previous')
		)  ) )
	and ( not ( contains(
                        (./ancestor::Block/descendant::IfStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.previous')
		) ) )
	and ( not ( contains(
                        (./ancestor::Block/descendant::IfStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.last')
		) ) )
	and ( not ( contains(
                        (./ancestor::Block/descendant::IfStatement/descendant::Name/attribute::Image),
                        concat(../../../VariableDeclarator/VariableDeclaratorId/attribute::Image,'.first')
		) ) )

         )
]
		        	
            	
  
		    
		    
	    
	    
        
        
        Example:
            
                    
            [
            // This is NOT appropriate !
            Statement stat = conn.createStatement();
            ResultSet rst = stat.executeQuery("SELECT name FROM person");
            rst.next(); // what if it returns a 'false' ?
            String firstName = rst.getString(1);

            // This is appropriate...
            Statement stat = conn.createStatement();
            ResultSet rst = stat.executeQuery("SELECT name FROM person");
            if (rst.next())
            {
                String firstName = rst.getString(1);
            }
            else
            {
                // here you deal with the error ( at least log it)
            }