Permissions.java

/**
 * Copyright (c) Codice Foundation
 * <p>
 * This is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser
 * General Public License as published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 * <p>
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details. A copy of the GNU Lesser General Public License
 * is distributed along with this program and can be found at
 * <http://www.gnu.org/licenses/lgpl.html>.
 */
package ddf.security.permission;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

import org.apache.commons.lang.StringUtils;

public class Permissions {

    private static final Pattern PATTERN = Pattern.compile(",");

    private Permissions() {

    }

    public static Map<String, Set<String>> parsePermissionsFromString(List<String> permStrings) {
        return parsePermissionsFromString(permStrings.toArray(new String[permStrings.size()]));
    }

    /**
     * Parses a string  array representation of permission attributes into a map
     *
     * @param permStrings array of permission strings in the format "permName=val1,val2"
     */
    public static Map<String, Set<String>> parsePermissionsFromString(String... permStrings) {
        Map<String, Set<String>> permissions = new HashMap<>();
        if (permStrings != null) {
            for (String perm : permStrings) {
                if (perm != null) {
                    String[] parts = perm.split("=");
                    if (parts.length == 2) {
                        String attributeName = parts[0];
                        Set<String> attributeValues = PATTERN.splitAsStream(parts[1])
                                .map(String::trim)
                                .collect(Collectors.toSet());
                        permissions.put(attributeName, attributeValues);
                    }
                }
            }
        }
        return permissions;
    }

    public static List<String> getPermissionsAsStrings(Map<String, Set<String>> attributes) {
        if (attributes == null) {
            return Collections.emptyList();
        }
        List<String> stringAttributes = new ArrayList<>(attributes.size());
        StringBuilder sb = new StringBuilder();
        for (Map.Entry<String, Set<String>> entry : attributes.entrySet()) {
            sb.append(entry.getKey());
            sb.append("=");
            sb.append(StringUtils.join(entry.getValue(), ","));
            stringAttributes.add(sb.toString());
            sb.setLength(0);
        }
        return stringAttributes;
    }
}