001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017 package org.apache.logging.log4j.core.config;
018
019 import java.util.ArrayList;
020 import java.util.HashMap;
021 import java.util.List;
022 import java.util.Map;
023
024 import org.apache.logging.log4j.core.config.plugins.util.PluginType;
025
026 /**
027 * A Configuration node.
028 */
029 public class Node {
030
031 /**
032 * Main plugin category for plugins which are represented as a configuration node. Such plugins tend to be
033 * available as XML elements in a configuration file.
034 *
035 * @since 2.1
036 */
037 public static final String CATEGORY = "Core";
038
039 private final Node parent;
040 private final String name;
041 private String value;
042 private final PluginType<?> type;
043 private final Map<String, String> attributes = new HashMap<String, String>();
044 private final List<Node> children = new ArrayList<Node>();
045 private Object object;
046
047
048 /**
049 * Creates a new instance of {@code Node} and initializes it
050 * with a name and the corresponding XML element.
051 *
052 * @param parent the node's parent.
053 * @param name the node's name.
054 * @param type The Plugin Type associated with the node.
055 */
056 public Node(final Node parent, final String name, final PluginType<?> type) {
057 this.parent = parent;
058 this.name = name;
059 this.type = type;
060 }
061
062 public Node() {
063 this.parent = null;
064 this.name = null;
065 this.type = null;
066 }
067
068 public Node(final Node node) {
069 this.parent = node.parent;
070 this.name = node.name;
071 this.type = node.type;
072 this.attributes.putAll(node.getAttributes());
073 this.value = node.getValue();
074 for (final Node child : node.getChildren()) {
075 this.children.add(new Node(child));
076 }
077 this.object = node.object;
078 }
079
080 public Map<String, String> getAttributes() {
081 return attributes;
082 }
083
084 public List<Node> getChildren() {
085 return children;
086 }
087
088 public boolean hasChildren() {
089 return !children.isEmpty();
090 }
091
092 public String getValue() {
093 return value;
094 }
095
096 public void setValue(final String value) {
097 this.value = value;
098 }
099
100 public Node getParent() {
101 return parent;
102 }
103
104 public String getName() {
105 return name;
106 }
107
108 public boolean isRoot() {
109 return parent == null;
110 }
111
112 public void setObject(final Object obj) {
113 object = obj;
114 }
115
116 @SuppressWarnings("unchecked")
117 public <T> T getObject() {
118 return (T) object;
119 }
120
121 /**
122 * Returns this node's object cast to the given class.
123 *
124 * @param clazz the class to cast this node's object to.
125 * @param <T> the type to cast to.
126 * @return this node's object.
127 * @since 2.1
128 */
129 public <T> T getObject(final Class<T> clazz) {
130 return clazz.cast(object);
131 }
132
133 /**
134 * Determines if this node's object is an instance of the given class.
135 *
136 * @param clazz the class to check.
137 * @return {@code true} if this node's object is an instance of the given class.
138 * @since 2.1
139 */
140 public boolean isInstanceOf(final Class<?> clazz) {
141 return clazz.isInstance(object);
142 }
143
144 public PluginType<?> getType() {
145 return type;
146 }
147
148 @Override
149 public String toString() {
150 if (object == null) {
151 return "null";
152 }
153 return type.isObjectPrintable() ? object.toString() :
154 type.getPluginClass().getName() + " with name " + name;
155 }
156 }