Matrix API stuff

MatrixUtil.jsp

<%@ page import="com.liferay.portal.kernel.json.JSONFactoryUtil" %>
<%@ page import="com.liferay.portal.kernel.jsonwebservice.JSONWebServiceActionsManagerUtil" %>
<%@ page import="com.liferay.portal.kernel.util.BigDecimalUtil" %>

<%@ page import="java.math.RoundingMode" %>

<%@ page import="java.util.ArrayList" %>
<%@ page import="java.util.List" %>
<%@ page import="java.util.Map" %>

<%!
public static class MatrixUtil {

	public static double getCompositeVisibilityValue(String jsonString) {
		List<Map<String, Number>> roleMaps = null;

		try {
			roleMaps = JSONFactoryUtil.looseDeserialize(jsonString, ArrayList.class);
		}
		catch (Exception e) {
			throw new RuntimeException("Bad json string. Must be an array.", e);
		}

		return getCompositeVisibilityValue(roleMaps);
	}

	public static double getCompositeVisibilityValue(List<Map<String, Number>> roleMaps) {
		double userWeightedDNO = 0;

		for (Map<String, Number> roleMap : roleMaps) {
			double roleUserWeightedDNO = BigDecimalUtil.multiply(roleMap.get("usersInRole"), roleMap.get("roleDNO"));

			userWeightedDNO = BigDecimalUtil.add(userWeightedDNO, roleUserWeightedDNO);
		}

		double numerator = 0;

		for (Map<String, Number> roleMap : roleMaps) {
			double roleValue = BigDecimalUtil.multiply(roleMap.get("roleWeight"), userWeightedDNO);

			numerator = BigDecimalUtil.add(numerator, roleValue);
		}

		double totalUsers = sum(roleMaps, "usersInRole");
		double roleWeightSum = sum(roleMaps, "roleWeight");

		double denominator = BigDecimalUtil.multiply(totalUsers, roleWeightSum);

		return BigDecimalUtil.divide(numerator, denominator, 6, RoundingMode.HALF_UP);
	}

	protected static double sum(List<Map<String, Number>> maps, String field) {
		double sum = 0;

		for (Map<String, Number> map : maps) {
			sum = BigDecimalUtil.add(sum, map.get(field));
		}

		return sum;
	}

}
%>

<%
JSONWebServiceActionsManagerUtil.registerJSONWebServiceAction("/matrix", MatrixUtil.class, MatrixUtil.class.getDeclaredMethod("getCompositeVisibilityValue", String.class), "/util/getCompositeVisibilityValue", "GET");
%>