source: references/src/main/java/geniusweb/references/Parameters.java@ 29

package geniusweb.references;

import java.util.HashMap;

/**
 * init parameters for a party. Object must be either a HashMap, List, String or
 * Number. Other objects may not deserialize properly. We never use blanket
 * Object deserializers (enableDefaultTyping) because of security reasons.
 *
 */
public class Parameters extends HashMap<String, Object> {

        /**
         * Getter with type-check
         * 
         * @param <T>       the expected type
         * @param paramname the parameter name that must be in the map
         * @param classType the expected value type for this parameter
         * @return object of requested type.
         * @throws IllegalArgumentException if the object is not available.
         */
        @SuppressWarnings("unchecked")
        public <T> T get(String paramname, Class<T> classType) {
                if (!containsKey(paramname) || !(classType.isInstance(get(paramname))))
                        throw new IllegalArgumentException(" Missing a parameter "
                                        + paramname + " with a " + classType.getName() + " value");
                return (T) get(paramname);
        }

        /**
         * 
         * @param name       the parameter name
         * @param defaultval the default value to return if parameter is not
         *                   available or not inside the given range. Can be null
         * @param min        the minimum value, or null if not applicable
         * @param max        the maximum value, or null if not applicable
         * @return the double value contained inside the parameter with the given
         *         name, or defaultval if the parameter does not exist, does not
         *         contain a double, or is outside [min, max].
         */
        public Double getDouble(String name, Double defaultval, Double min,
                        Double max) {
                if (!containsKey(name) || !(get(name) instanceof Double))
                        return defaultval;
                Double val = (Double) get(name);
                if (min != null && val < min)
                        return defaultval;
                if (max != null && val > max)
                        return defaultval;
                return val;
        }
}