org.springframework.boot.bind.YamlJavaBeanPropertyConstructor Maven / Gradle / Ivy
/*
* Copyright 2012-2014 the original author or authors.
*
* 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.springframework.boot.bind;
import java.beans.IntrospectionException;
import java.util.HashMap;
import java.util.Map;
import org.yaml.snakeyaml.constructor.Constructor;
import org.yaml.snakeyaml.introspector.Property;
import org.yaml.snakeyaml.introspector.PropertyUtils;
import org.yaml.snakeyaml.nodes.NodeId;
/**
* Extended version of snakeyaml's Constructor class to facilitate mapping custom YAML
* keys to JavaBean property names.
*
* @author Luke Taylor
*/
public class YamlJavaBeanPropertyConstructor extends Constructor {
private final Map, Map> properties = new HashMap, Map>();
private final PropertyUtils propertyUtils = new PropertyUtils();
public YamlJavaBeanPropertyConstructor(Class theRoot) {
super(theRoot);
this.yamlClassConstructors.put(NodeId.mapping,
new CustomPropertyConstructMapping());
}
public YamlJavaBeanPropertyConstructor(Class theRoot,
Map, Map> propertyAliases) {
this(theRoot);
for (Class key : propertyAliases.keySet()) {
Map map = propertyAliases.get(key);
if (map != null) {
for (String alias : map.keySet()) {
addPropertyAlias(alias, key, map.get(alias));
}
}
}
}
/**
* Adds an alias for a JavaBean property name on a particular type. The values of YAML
* keys with the alias name will be mapped to the JavaBean property.
* @param alias the alias to map
* @param type the type of property
* @param name the property name
*/
protected final void addPropertyAlias(String alias, Class type, String name) {
Map typeMap = this.properties.get(type);
if (typeMap == null) {
typeMap = new HashMap();
this.properties.put(type, typeMap);
}
try {
typeMap.put(alias, this.propertyUtils.getProperty(type, name));
}
catch (IntrospectionException ex) {
throw new RuntimeException(ex);
}
}
/**
* Custom {@code ConstructMapping} to resolve properties.
*/
class CustomPropertyConstructMapping extends ConstructMapping {
@Override
protected Property getProperty(Class type, String name)
throws IntrospectionException {
Map forType = YamlJavaBeanPropertyConstructor.this.properties
.get(type);
Property property = (forType == null ? null : forType.get(name));
return (property == null ? super.getProperty(type, name) : property);
}
}
}