public void systemParametersValidation(SystemParameter[] systemParameters) throws AnnotationValidationException {
        // Iterate over all @SystemParameter annotated elements.
        for (SystemParameter systemParameter : systemParameters) {
            String systemParameterName = systemParameter.name();
            //Check if the @SystemParameter name is empty.
            if (systemParameterName.isEmpty()) {
                throw new AnnotationValidationException(MessageFormat.format("The @Extension -> " +
                        "@SystemParameter -> name annotated in class {0} is null or empty.", extensionClassFullName));
            }
            //Check if the @SystemParameter description is empty.
            if (systemParameter.description().isEmpty()) {
                throw new AnnotationValidationException(MessageFormat.format("The @Extension -> " +
                                "@SystemParameter -> name:{0} -> description annotated in class {1} is null or empty.",
                        systemParameterName, extensionClassFullName));
            }
            //Check if the @SystemParameter defaultValue is empty.
            if (systemParameter.defaultValue().isEmpty()) {
                throw new AnnotationValidationException(MessageFormat.format("The @Extension -> " +
                                "@SystemParameter -> name:{0} -> defaultValue annotated in class {1} is null or empty.",
                        systemParameterName, extensionClassFullName));
            }
            //Check if the @SystemParameter possibleParameters is empty.
            if (systemParameter.possibleParameters().length == 0) {
                throw new AnnotationValidationException(MessageFormat.format("The @Extension -> " +
                        "@SystemParameter -> name:{0} -> possibleParameters annotated in class {1} is " +
                        "null or empty.", systemParameterName, extensionClassFullName));
            }
        }
    }
This method uses for validate @Extension / @SystemParameter elements.

@param systemParameters system property array which needs to be validate.
@throws AnnotationValidationException whenever if the validate rule violate, throws the annotation validate
                                      exception with proper message.
modules/siddhi-annotations/src/main/java/io/siddhi/annotation/processor/AbstractAnnotationProcessor.java