NodeBase.java
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上传日期:2018-01-08
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- /**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF 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.apache.hadoop.net;
- /** A base class that implements interface Node
- *
- */
- public class NodeBase implements Node {
- public final static char PATH_SEPARATOR = '/';
- public final static String PATH_SEPARATOR_STR = "/";
- public final static String ROOT = ""; // string representation of root
-
- protected String name; //host:port#
- protected String location; //string representation of this node's location
- protected int level; //which level of the tree the node resides
- protected Node parent; //its parent
-
- /** Default constructor */
- public NodeBase() {
- }
-
- /** Construct a node from its path
- * @param path
- * a concatenation of this node's location, the path seperator, and its name
- */
- public NodeBase(String path) {
- path = normalize(path);
- int index = path.lastIndexOf(PATH_SEPARATOR);
- if (index== -1) {
- set(ROOT, path);
- } else {
- set(path.substring(index+1), path.substring(0, index));
- }
- }
-
- /** Construct a node from its name and its location
- * @param name this node's name
- * @param location this node's location
- */
- public NodeBase(String name, String location) {
- set(name, normalize(location));
- }
-
- /** Construct a node from its name and its location
- * @param name this node's name
- * @param location this node's location
- * @param parent this node's parent node
- * @param level this node's level in the tree
- */
- public NodeBase(String name, String location, Node parent, int level) {
- set(name, normalize(location));
- this.parent = parent;
- this.level = level;
- }
- /* set this node's name and location */
- private void set(String name, String location) {
- if (name != null && name.contains(PATH_SEPARATOR_STR))
- throw new IllegalArgumentException(
- "Network location name contains /: "+name);
- this.name = (name==null)?"":name;
- this.location = location;
- }
-
- /** Return this node's name */
- public String getName() { return name; }
-
- /** Return this node's network location */
- public String getNetworkLocation() { return location; }
-
- /** Set this node's network location */
- public void setNetworkLocation(String location) { this.location = location; }
-
- /** Return this node's path */
- public static String getPath(Node node) {
- return node.getNetworkLocation()+PATH_SEPARATOR_STR+node.getName();
- }
-
- /** Return this node's string representation */
- public String toString() {
- return getPath(this);
- }
- /** Normalize a path */
- static public String normalize(String path) {
- if (path == null || path.length() == 0) return ROOT;
-
- if (path.charAt(0) != PATH_SEPARATOR) {
- throw new IllegalArgumentException(
- "Network Location path does not start with "
- +PATH_SEPARATOR_STR+ ": "+path);
- }
-
- int len = path.length();
- if (path.charAt(len-1) == PATH_SEPARATOR) {
- return path.substring(0, len-1);
- }
- return path;
- }
-
- /** Return this node's parent */
- public Node getParent() { return parent; }
-
- /** Set this node's parent */
- public void setParent(Node parent) {
- this.parent = parent;
- }
-
- /** Return this node's level in the tree.
- * E.g. the root of a tree returns 0 and its children return 1
- */
- public int getLevel() { return level; }
-
- /** Set this node's level in the tree */
- public void setLevel(int level) {
- this.level = level;
- }
- }