/**
* Copyright (c) 2008-2012, 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.representer;
import java.beans.IntrospectionException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.yaml.snakeyaml.DumperOptions.FlowStyle;
import org.yaml.snakeyaml.error.YAMLException;
import org.yaml.snakeyaml.introspector.Property;
import org.yaml.snakeyaml.nodes.MappingNode;
import org.yaml.snakeyaml.nodes.Node;
import org.yaml.snakeyaml.nodes.NodeId;
import org.yaml.snakeyaml.nodes.NodeTuple;
import org.yaml.snakeyaml.nodes.ScalarNode;
import org.yaml.snakeyaml.nodes.SequenceNode;
import org.yaml.snakeyaml.nodes.Tag;
/**
* Represent JavaBeans
*/
public class Representer extends SafeRepresenter {
public Representer() {
this.representers.put(null, new RepresentJavaBean());
}
protected class RepresentJavaBean implements Represent {
public Node representData(Object data) {
try {
return representJavaBean(getProperties(data.getClass()), data);
} catch (IntrospectionException e) {
throw new YAMLException(e);
}
}
}
/**
* Tag logic:<br/>
* - explicit root tag is set in serializer <br/>
* - if there is a predefined class tag it is used<br/>
* - a global tag with class name is always used as tag. The JavaBean parent
* of the specified JavaBean may set another tag (tag:yaml.org,2002:map)
* when the property class is the same as runtime class
*
* @param properties
* JavaBean getters
* @param javaBean
* instance for Node
* @return Node to get serialized
*/
protected MappingNode representJavaBean(Set<Property> properties, Object javaBean) {
List<NodeTuple> value = new ArrayList<NodeTuple>(properties.size());
Tag tag;
Tag customTag = classTags.get(javaBean.getClass());
tag = customTag != null ? customTag : new Tag(javaBean.getClass());
// flow style will be chosen by BaseRepresenter
MappingNode node = new MappingNode(tag, value, null);
representedObjects.put(javaBean, node);
boolean bestStyle = true;
for (Property property : properties) {
Object memberValue = property.get(javaBean);
Tag customPropertyTag = memberValue == null ? null : classTags.get(memberValue
.getClass());
NodeTuple tuple = representJavaBeanProperty(javaBean, property, memberValue,
customPropertyTag);
if (tuple == null) {
continue;
}
if (((ScalarNode) tuple.getKeyNode()).getStyle() != null) {
bestStyle = false;
}
Node nodeValue = tuple.getValueNode();
if (!((nodeValue instanceof ScalarNode && ((ScalarNode) nodeValue).getStyle() == null))) {
bestStyle = false;
}
value.add(tuple);
}
if (defaultFlowStyle != FlowStyle.AUTO) {
node.setFlowStyle(defaultFlowStyle.getStyleBoolean());
} else {
node.setFlowStyle(bestStyle);
}
return node;
}
/**
* Represent one JavaBean property.
*
* @param javaBean
* - the instance to be represented
* @param property
* - the property of the instance
* @param propertyValue
* - value to be represented
* @param customTag
* - user defined Tag
* @return NodeTuple to be used in a MappingNode. Return null to skip the
* property
*/
protected NodeTuple representJavaBeanProperty(Object javaBean, Property property,
Object propertyValue, Tag customTag) {
ScalarNode nodeKey = (ScalarNode) representData(property.getName());
// the first occurrence of the node must keep the tag
boolean hasAlias = this.representedObjects.containsKey(propertyValue);
Node nodeValue = representData(propertyValue);
if (propertyValue != null && !hasAlias) {
NodeId nodeId = nodeValue.getNodeId();
if (customTag == null) {
if (nodeId == NodeId.scalar) {
if (propertyValue instanceof Enum<?>) {
nodeValue.setTag(Tag.STR);
}
} else {
if (nodeId == NodeId.mapping) {
if (property.getType() == propertyValue.getClass()) {
if (!(propertyValue instanceof Map<?, ?>)) {
if (!nodeValue.getTag().equals(Tag.SET)) {
nodeValue.setTag(Tag.MAP);
}
}
}
}
checkGlobalTag(property, nodeValue, propertyValue);
}
}
}
return new NodeTuple(nodeKey, nodeValue);
}
/**
* Remove redundant global tag for a type safe (generic) collection if it is
* the same as defined by the JavaBean property
*
* @param property
* - JavaBean property
* @param node
* - representation of the property
* @param object
* - instance represented by the node
*/
@SuppressWarnings("unchecked")
protected void checkGlobalTag(Property property, Node node, Object object) {
Class<?>[] arguments = property.getActualTypeArguments();
if (arguments != null) {
if (node.getNodeId() == NodeId.sequence) {
// apply map tag where class is the same
Class<? extends Object> t = arguments[0];
SequenceNode snode = (SequenceNode) node;
Iterable<Object> memberList;
if (object.getClass().isArray()) {
memberList = Arrays.asList((Object[]) object);
} else {
// list
memberList = (Iterable<Object>) object;
}
Iterator<Object> iter = memberList.iterator();
for (Node childNode : snode.getValue()) {
Object member = iter.next();
if (member != null) {
if (t.equals(member.getClass()))
if (childNode.getNodeId() == NodeId.mapping) {
childNode.setTag(Tag.MAP);
}
}
}
} else if (object instanceof Set) {
Class<?> t = arguments[0];
MappingNode mnode = (MappingNode) node;
Iterator<NodeTuple> iter = mnode.getValue().iterator();
Set<?> set = (Set<?>) object;
for (Object member : set) {
NodeTuple tuple = iter.next();
Node keyNode = tuple.getKeyNode();
if (t.equals(member.getClass())) {
if (keyNode.getNodeId() == NodeId.mapping) {
keyNode.setTag(Tag.MAP);
}
}
}
} else if (object instanceof Map) {
Class<?> keyType = arguments[0];
Class<?> valueType = arguments[1];
MappingNode mnode = (MappingNode) node;
for (NodeTuple tuple : mnode.getValue()) {
resetTag(keyType, tuple.getKeyNode());
resetTag(valueType, tuple.getValueNode());
}
} else {
// the type for collection entries cannot be
// detected
}
}
}
private void resetTag(Class<? extends Object> type, Node node) {
Tag tag = node.getTag();
if (tag.matches(type)) {
if (Enum.class.isAssignableFrom(type)) {
node.setTag(Tag.STR);
} else {
node.setTag(Tag.MAP);
}
}
}
/**
* Get JavaBean properties to be serialised. The order is respected. This
* method may be overridden to provide custom property selection or order.
*
* @param type
* - JavaBean to inspect the properties
* @return properties to serialise
*/
protected Set<Property> getProperties(Class<? extends Object> type)
throws IntrospectionException {
return getPropertyUtils().getProperties(type);
}
}