| /** |
| * Copyright (c) 2008, http://www.snakeyaml.org |
| * |
| * Licensed 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.yaml.snakeyaml.nodes; |
| |
| import org.yaml.snakeyaml.error.Mark; |
| |
| /** |
| * Base class for all nodes. |
| * <p> |
| * The nodes form the node-graph described in the <a |
| * href="http://yaml.org/spec/1.1/">YAML Specification</a>. |
| * </p> |
| * <p> |
| * While loading, the node graph is usually created by the |
| * {@link org.yaml.snakeyaml.composer.Composer}, and later transformed into |
| * application specific Java classes by the classes from the |
| * {@link org.yaml.snakeyaml.constructor} package. |
| * </p> |
| */ |
| public abstract class Node { |
| private Tag tag; |
| private Mark startMark; |
| protected Mark endMark; |
| private Class<? extends Object> type; |
| private boolean twoStepsConstruction; |
| /** |
| * true when the tag is assigned by the resolver |
| */ |
| protected boolean resolved; |
| protected Boolean useClassConstructor; |
| |
| public Node(Tag tag, Mark startMark, Mark endMark) { |
| setTag(tag); |
| this.startMark = startMark; |
| this.endMark = endMark; |
| this.type = Object.class; |
| this.twoStepsConstruction = false; |
| this.resolved = true; |
| this.useClassConstructor = null; |
| } |
| |
| /** |
| * Tag of this node. |
| * <p> |
| * Every node has a tag assigned. The tag is either local or global. |
| * |
| * @return Tag of this node. |
| */ |
| public Tag getTag() { |
| return this.tag; |
| } |
| |
| public Mark getEndMark() { |
| return endMark; |
| } |
| |
| /** |
| * For error reporting. |
| * |
| * @see "class variable 'id' in PyYAML" |
| * @return scalar, sequence, mapping |
| */ |
| public abstract NodeId getNodeId(); |
| |
| public Mark getStartMark() { |
| return startMark; |
| } |
| |
| public void setTag(Tag tag) { |
| if (tag == null) { |
| throw new NullPointerException("tag in a Node is required."); |
| } |
| this.tag = tag; |
| } |
| |
| /** |
| * Two Nodes are never equal. |
| */ |
| @Override |
| public final boolean equals(Object obj) { |
| return super.equals(obj); |
| } |
| |
| public Class<? extends Object> getType() { |
| return type; |
| } |
| |
| public void setType(Class<? extends Object> type) { |
| if (!type.isAssignableFrom(this.type)) { |
| this.type = type; |
| } |
| } |
| |
| public void setTwoStepsConstruction(boolean twoStepsConstruction) { |
| this.twoStepsConstruction = twoStepsConstruction; |
| } |
| |
| /** |
| * Indicates if this node must be constructed in two steps. |
| * <p> |
| * Two-step construction is required whenever a node is a child (direct or |
| * indirect) of it self. That is, if a recursive structure is build using |
| * anchors and aliases. |
| * </p> |
| * <p> |
| * Set by {@link org.yaml.snakeyaml.composer.Composer}, used during the |
| * construction process. |
| * </p> |
| * <p> |
| * Only relevant during loading. |
| * </p> |
| * |
| * @return <code>true</code> if the node is self referenced. |
| */ |
| public boolean isTwoStepsConstruction() { |
| return twoStepsConstruction; |
| } |
| |
| @Override |
| public final int hashCode() { |
| return super.hashCode(); |
| } |
| |
| public boolean useClassConstructor() { |
| if (useClassConstructor == null) { |
| if (!tag.isSecondary() && isResolved() && !Object.class.equals(type) |
| && !tag.equals(Tag.NULL)) { |
| return true; |
| } else if (tag.isCompatible(getType())) { |
| // the tag is compatible with the runtime class |
| // the tag will be ignored |
| return true; |
| } else { |
| return false; |
| } |
| } |
| return useClassConstructor.booleanValue(); |
| } |
| |
| public void setUseClassConstructor(Boolean useClassConstructor) { |
| this.useClassConstructor = useClassConstructor; |
| } |
| |
| /** |
| * Indicates if the tag was added by |
| * {@link org.yaml.snakeyaml.resolver.Resolver}. |
| * |
| * @return <code>true</code> if the tag of this node was resolved</code> |
| */ |
| public boolean isResolved() { |
| return resolved; |
| } |
| } |