private BigDecimal getEffectiveMaxValue(FacesContext context, InputNumber component) {
        String maximumValue = component.getMaxValue();
        if (maximumValue == null) {
            maximumValue = determineMaximumFromType(context, component);
        }
        if (maximumValue == null) {
            maximumValue = DEFAULT_MAX_VALUE;
        }

        try {
            return new BigDecimal(maximumValue);
        }
        catch (Exception e) {
            throw new IllegalArgumentException("Error converting  [" + maximumValue + "] to a decimal value for maxValue", e);
        }
    }
Get the effective maximum Value (as interpreted in the AutoNumeric plugin)
@param context faces context
@param component the InputNumber component
@return the maximumValue property as BigDecimal, or the AutoNumeric default value if empty
primefaces/src/main/java/org/primefaces/component/inputnumber/InputNumberRenderer.java