org.jpmml.model.XPathUtil Maven / Gradle / Ivy

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/*
 * Copyright (c) 2014 Villu Ruusmann
 */
package org.jpmml.model;

import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

import org.dmg.pmml.PMMLObject;

public class XPathUtil {

	private XPathUtil(){
	}

	static
	public String formatElement(Class elementClazz){
		return getElementName(elementClazz);
	}

	static
	public String formatElementOrAttribute(Field field){
		return formatElementOrAttribute((Class)field.getDeclaringClass(), field);
	}

	static
	public String formatElementOrAttribute(Class elementClazz, Field field){
		XmlElement element = field.getAnnotation(XmlElement.class);
		XmlAttribute attribute = field.getAnnotation(XmlAttribute.class);

		if(element != null){
			Class childElementClazz = field.getType();

			if((List.class).isAssignableFrom(childElementClazz)){
				ParameterizedType listType = (ParameterizedType)field.getGenericType();

				Type[] typeArguments = listType.getActualTypeArguments();
				if(typeArguments.length != 1){
					throw new IllegalArgumentException();
				}

				childElementClazz = (Class)typeArguments[0];
			}

			try {
				return getElementName(elementClazz) + "/" + getElementName(childElementClazz);
			} catch(IllegalArgumentException iae){
				return getElementName(elementClazz) + "/" + element.name();
			}
		} else

		if(attribute != null){
			return getElementName(elementClazz) + "@" + attribute.name();
		}

		throw new IllegalArgumentException();
	}

	static
	public String formatAttribute(Field field, Object value){
		return formatAttribute((Class)field.getDeclaringClass(), field, value);
	}

	static
	public String formatAttribute(Class elementClazz, Field field, Object value){
		XmlAttribute attribute = field.getAnnotation(XmlAttribute.class);

		if(attribute != null){
			return formatElementOrAttribute(elementClazz, field) + (value != null ? ("=" + String.valueOf(value)) : "");
		}

		throw new IllegalArgumentException();
	}

	static
	private String getElementName(Class clazz){

		while(clazz != null){
			XmlRootElement rootElement = clazz.getAnnotation(XmlRootElement.class);

			if(rootElement != null){
				return rootElement.name();
			}

			clazz = clazz.getSuperclass();
		}

		throw new IllegalArgumentException();
	}
}