columnconstraint.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.security;

/**
 * <p>Title: </p>
 * <p>Description:  This class contains database table's column constraint information. It's
 *                  an application level and role-based security constraint. A security constraint
 *                  can be a function constraint or a column constraint
 *                  depending on business or security implementation structure.
 * </p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: eBusiness Inc., All right reserved</p>
 * @author unascribed
 * @version 1.0
 */

import java.util.Set;
import java.util.Map;

public class ColumnConstraint
{
    //Store roleID(key) and a set(value) of table column controls that apply to this role
    private static Map policies;
    private static Map roleIndicators;

    public ColumnConstraint() {}

    public static void init(Map colPolicies, Map indicators)
    {
        policies = colPolicies;
        roleIndicators = indicators;
    }

    /**
     * Check to see if the specified column is restricted on the specified roles.
     *
     * As long as the column is not restricted on one role, the column is not restricted
     */
    public static boolean isRestrictedAccessOnColumn(String columnName, String[] roles)
    {
        Set colPolicy;
        String indicator;
        for (int i = 0; i < roles.length; i++)
        {
            colPolicy = (Set)policies.get(roles[i]);
            indicator = (String)roleIndicators.get(roles[i]);
            if ("restricted".equals(indicator))
            {
                if(colPolicy != null)
                {
                    if (colPolicy.contains("NONE")) //no restriction at all, column is NOT restricted
                        return false;
                    if (!colPolicy.contains(columnName)) //no restriction was found for the role, so the column is NOT restricted
                        return false;
                }
            }
            else
            {
                 if(colPolicy != null)
                 {
                     if (colPolicy.contains("ALL")) //no restriction at all, column is NOT restricted
                         return false;
                     if (colPolicy.contains(columnName)) //no restriction was found for the role, so the column is NOT restricted
                         return false;
                 }
            }
        }
        //No found for the roles or found restrictions on all the specified roles, column is restricted
        return true;
    }

     /**
     * Check to see if the specified column is restricted for edit on the specified roles.
     *
     * As long as the column is not restricted on one role, the column is not restricted
     */
    public static boolean isRestrictedEditOnColumn(String columnName, String[] roles)
    {
        Set colPolicy;
        String indicator;
        for (int i = 0; i < roles.length; i++)
        {
            colPolicy = (Set)policies.get(roles[i]);
            indicator = (String)roleIndicators.get(roles[i]);
            if ("restricted".equals(indicator))
            {
                if(colPolicy != null)
                {
                    if (colPolicy.contains("NONE")) //no restriction at all, column is NOT restricted
                        return false;
                    if (!colPolicy.contains(columnName + ".Edit") && !colPolicy.contains(columnName)) //no restriction was found for the role, so the column is editable
                        return false;
                }
            }
            else
            {
                if(colPolicy != null)
                {
                    if (colPolicy.contains("ALL")) //has ALL access, function is NOT restricted
                        return false;
                   if (colPolicy.contains(columnName + ".Edit") || colPolicy.contains(columnName)) //no restriction was found for the role, so the column is editable
                        return false;
                 }
            }
        }
        //No found for the roles or found restrictions on all the specified roles, column is restricted
        return true;
    }
}