com.yqjr.framework.component.mapper.JaxbMapper Maven / Gradle / Ivy

/**
 * Copyright (c) 2005-2012 springside.org.cn
 */
package com.yqjr.framework.component.mapper;

import java.io.StringReader;
import java.io.StringWriter;
import java.util.Collection;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlAnyElement;
import javax.xml.namespace.QName;

import org.apache.commons.lang3.StringUtils;
import org.springframework.http.converter.HttpMessageConversionException;
import org.springframework.util.Assert;

import com.yqjr.framework.datatype.BizzException;
import com.yqjr.framework.utils.Reflections;

/**
 * 使用Jaxb2.0实现XML-Java Object的Mapper.
 * 
 * 在创建时需要设定所有需要序列化的Root对象的Class. 特别支持Root对象是Collection的情形.
 * 
 * @author calvin
 * @version 2013-01-15
 */
@SuppressWarnings("rawtypes")
public class JaxbMapper {

	private static ConcurrentMap jaxbContexts = new ConcurrentHashMap();

	/**
	 * Java Object-Xml without encoding.
	 * @param root Object
	 * @return String
	 */
	public static String toXml(Object root) {
		Class clazz = Reflections.getUserClass(root);
		return toXml(root, clazz, null);
	}

	/**
	 * Java Object-Xml with encoding.
	 * @param root Object
	 * @param encoding String
	 * @return String
	 */
	public static String toXml(Object root, String encoding) {
		Class clazz = Reflections.getUserClass(root);
		return toXml(root, clazz, encoding);
	}

	/**
	 * Java Object-Xml with encoding.
	 * @param root Object
	 * @param clazz Class
	 * @param encoding String
	 * @return String
	 */
	public static String toXml(Object root, Class clazz, String encoding) {
		try {
			StringWriter writer = new StringWriter();
			createMarshaller(clazz, encoding).marshal(root, writer);
			return writer.toString();
		} catch (JAXBException e) {
			throw new BizzException(e);
		}
	}

	/**
	 * Java Collection-Xml without encoding, 特别支持Root Element是Collection的情形.
	 * @param root Collection
	 * @param rootName String
	 * @param clazz Class
	 * @return String
	 */
	public static String toXml(Collection root, String rootName, Class clazz) {
		return toXml(root, rootName, clazz, null);
	}

	/**
	 * Java Collection-Xml with encoding, 特别支持Root Element是Collection的情形.
	 * @param root Collection
	 * @param rootName String
	 * @param clazz Class
	 * @param encoding String
	 * @return String
	 */
	public static String toXml(Collection root, String rootName, Class clazz, String encoding) {
		try {
			CollectionWrapper wrapper = new CollectionWrapper();
			wrapper.collection = root;

			JAXBElement wrapperElement = new JAXBElement(new QName(rootName),
					CollectionWrapper.class, wrapper);

			StringWriter writer = new StringWriter();
			createMarshaller(clazz, encoding).marshal(wrapperElement, writer);

			return writer.toString();
		} catch (JAXBException e) {
			throw new BizzException(e);
		}
	}

	/**
	 * Xml-Java Object.
	 * @param xml String
	 * @param clazz Class
	 * @param  返回T
	 * @return 返回数据
	 */
	@SuppressWarnings("unchecked")
	public static  T fromXml(String xml, Class clazz) {
		try {
			StringReader reader = new StringReader(xml);
			return (T) createUnmarshaller(clazz).unmarshal(reader);
		} catch (JAXBException e) {
			throw new BizzException(e);
		}
	}

	/**
	 * 创建Marshaller并设定encoding(可为null). 线程不安全，需要每次创建或pooling。
	 * @param clazz Class
	 * @param encoding String
	 * @return Marshaller
	 */
	public static Marshaller createMarshaller(Class clazz, String encoding) {
		try {
			JAXBContext jaxbContext = getJaxbContext(clazz);

			Marshaller marshaller = jaxbContext.createMarshaller();

			marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
			marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);

			if (StringUtils.isNotBlank(encoding)) {
				marshaller.setProperty(Marshaller.JAXB_ENCODING, encoding);
			}

			return marshaller;
		} catch (JAXBException e) {
			throw new BizzException(e);
		}
	}

	/**
	 * 创建UnMarshaller. 线程不安全，需要每次创建或pooling。
	 * @param clazz Class
	 * @return Unmarshaller
	 */
	public static Unmarshaller createUnmarshaller(Class clazz) {
		try {
			JAXBContext jaxbContext = getJaxbContext(clazz);
			return jaxbContext.createUnmarshaller();
		} catch (JAXBException e) {
			throw new BizzException(e);
		}
	}

	protected static JAXBContext getJaxbContext(Class clazz) {
		Assert.notNull(clazz, "'clazz' must not be null");
		JAXBContext jaxbContext = jaxbContexts.get(clazz);
		if (jaxbContext == null) {
			try {
				jaxbContext = JAXBContext.newInstance(clazz, CollectionWrapper.class);
				jaxbContexts.putIfAbsent(clazz, jaxbContext);
			} catch (JAXBException ex) {
				throw new HttpMessageConversionException(
						"Could not instantiate JAXBContext for class [" + clazz + "]: " + ex.getMessage(), ex);
			}
		}
		return jaxbContext;
	}

	/**
	 * 封装Root Element 是 Collection的情况.
	 */
	public static class CollectionWrapper {

		@XmlAnyElement
		protected Collection collection;
	}

}