From a84edd7a99d58fdb512084c98910c98f37c393f7 Mon Sep 17 00:00:00 2001 From: milanperera Date: Fri, 2 Oct 2015 16:40:52 +0530 Subject: [PATCH] Added seperate permission tree class --- .../config/permission/PermissionTree.java | 112 ++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/config/permission/PermissionTree.java diff --git a/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/config/permission/PermissionTree.java b/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/config/permission/PermissionTree.java new file mode 100644 index 0000000000..4017ae059b --- /dev/null +++ b/components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/config/permission/PermissionTree.java @@ -0,0 +1,112 @@ +/* + * Copyright (c) 2015, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. + * + * WSO2 Inc. licenses this file to you under the Apache License, + * Version 2.0 (the "License"); you may not use this file except + * in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.wso2.carbon.device.mgt.core.config.permission; + +import org.apache.commons.logging.Log; +import org.apache.commons.logging.LogFactory; + +import java.util.StringTokenizer; + +/** + * This class represents a tree data structure which will be used for adding and retrieving permissions. + */ +public class PermissionTree { + + private PermissionNode rootNode; + private static final String DYNAMIC_PATH_NOTATION = "*"; + private static final Log log = LogFactory.getLog(PermissionTree.class); + + public PermissionTree() { + rootNode = new PermissionNode("/"); // initializing the root node. + } + + /** + * This method is used to add permissions to the tree. Once it receives the permission + * it will traverse through the given request path with respect to the permission and place + * the permission in the appropriate place in the tree. + * + * @param permission Permission object. + */ + public void addPermission(Permission permission) { + StringTokenizer st = new StringTokenizer(permission.getUrl(), "/"); + PermissionNode tempRoot = rootNode; + PermissionNode tempChild; + while (st.hasMoreTokens()) { + tempChild = new PermissionNode(st.nextToken()); + tempRoot = addPermissionNode(tempRoot, tempChild); + } + tempRoot.addPermission(permission.getMethod(), permission); //setting permission to the vertex + if (log.isDebugEnabled()) { + log.debug("Added permission '" + permission.getName() + "'"); + } + } + + /** + * This method is used to add vertex to the graph. The method will check for the given child + * whether exists within the list of children of the given parent. + * + * @param parent Parent PermissionNode. + * @param child Child PermissionNode. + * @return returns the newly created child or the existing child. + */ + private PermissionNode addPermissionNode(PermissionNode parent, PermissionNode child) { + PermissionNode existChild = parent.getChild(child.getPathName()); + if (existChild == null) { + parent.addChild(child); + return child; + } + return existChild; + } + + /** + * This method is used to retrieve the permission for a given url and http method. + * Breath First Search (BFS) is used to traverse the tree. + * + * @param url Request URL. + * @param httpMethod HTTP method of the request. + * @return returns the permission with related to the request path or null if there is + * no any permission that is stored with respected to the given request path. + */ + public Permission getPermission(String url, String httpMethod) { + StringTokenizer st = new StringTokenizer(url, "/"); + PermissionNode tempRoot = rootNode; + while (st.hasMoreTokens()) { + String currentToken = st.nextToken(); + + // returns the child node which matches with the 'currentToken' path. + tempRoot = tempRoot.getChild(currentToken); + + // if tempRoot is null, that means 'currentToken' is not matched with the child's path. + // It means that it is at a point where the request must have dynamic path variables. + // Therefor it looks for '*' in the request path. ('*' denotes dynamic path variable). + if (tempRoot == null) { + tempRoot = tempRoot.getChild(DYNAMIC_PATH_NOTATION); + // if tempRoot is null, that means there is no any permission which matches with the + // given path + if (tempRoot == null) { + if (log.isDebugEnabled()) { + log.debug("Permission for request path '" + url + "' does not exist"); + } + return null; + } + } + } + return tempRoot.getPermission(httpMethod); + } +}