EclipseLink MOXy's JAXB 入门

EclipseLink MOXy的JAXB实现可以定制生成的XML文件。

 

一  如何使用 EclipseLink的 MOXy的JAXB特性

1) 引入 org.eclipse.persistence.moxy_2.3.1.v20110908-r10021.jar,org.eclipse.persistence.core.jar或者eclipselink.jar

2) 创建jaxb.properties

javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory

 将其放在模型对象的同级目录包之下。

 

二 简单案例

moxy.pojo.Animal.java

package moxy.pojo;
import javax.xml.bind.annotation.XmlTransient;
import org.eclipse.persistence.oxm.annotations.XmlPath;
@XmlTransient
public class Animal {
	@XmlPath("xml/id/text()")
	private String id;
	@XmlPath("xml/name/text()")
	private String name;
	@XmlPath("xml/desc/text()")
	private String desc;

	public Animal() {}

	public Animal(String id, String name, String desc) {
		this.id = id;
		this.name = name;
		this.desc = desc;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getDesc() {
		return desc;
	}

	public void setDesc(String desc) {
		this.desc = desc;
	}

	@Override
	public String toString() {
		return this.id+":"+this.name+":"+this.desc;
	}
	
	
}

 

 moxy.pojo.Dog.java

package moxy.pojo;

import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

//@XmlTransient
@XmlRootElement
@XmlAccessorType
public class Dog extends Animal {
	private String color;

	public String getColor() {
		return color;
	}

	public void setColor(String color) {
		this.color = color;
	}

}

 

moxy.pojo.package.java

@XmlSchema(namespace="this is the default namespace",elementFormDefault=javax.xml.bind.annotation.XmlNsForm.QUALIFIED)
package moxy.pojo;
import javax.xml.bind.annotation.XmlSchema;

 

moxy/pojo/jaxb.properties

javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory

 

util.JAXBUtil.java

package util;

import java.io.ByteArrayInputStream;
import java.io.StringWriter;
import java.io.Writer;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;

public class JAXBUtil {
	  public static String marshalData(Object object) throws Exception {  
	        JAXBContext context = JAXBContext.newInstance(object.getClass());  
	  
	        Marshaller marshaller = context.createMarshaller();  
	        marshaller.setProperty(Marshaller.JAXB_ENCODING, "utf-8");// 编码格式  
	        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);// 是否格式化生成的xml串  
	        // 是否省略xml头信息（<?xml version="1.0" encoding="gb2312" standalone="yes"?>）  
	        marshaller.setProperty(Marshaller.JAXB_FRAGMENT, false);  
	        Writer writer =new StringWriter();
	        marshaller.marshal(object,writer);  
	        writer.close();
	        return writer.toString();
	    }  
	  
	    // 解组数据  
	    @SuppressWarnings("unchecked")
		public static <T> T unmarshalData(String xml,Class<T> clazz) throws Exception {  
	        JAXBContext context = JAXBContext.newInstance(clazz);  
	  
	        Unmarshaller unmarshaller = context.createUnmarshaller();  
	  
	        T object = (T) unmarshaller.unmarshal(new ByteArrayInputStream(xml.getBytes()));  
	  
	        return object;
	    }  
}

 

 测试类 moxy.test.Main.java

package moxy.test;
import moxy.pojo.Dog;
import moxy.pojo.Animal;
import util.JAXBUtil;
public class Main {

	public static void main(String[] args) throws Exception {
		testDog();
	}
	
	public static void testDog()throws Exception{
		System.out.println("marshal data");
		Dog dog = new Dog();
		dog.setId("001");
		dog.setName("dog");
		dog.setDesc("lovely dog");
		dog.setColor("yellow");
		
		String xml = JAXBUtil.marshalData(dog);
		System.out.println(xml);

		System.out.println("unmarshal data");
		Dog object = JAXBUtil.unmarshalData(xml, Dog.class);
		System.out.println(object);
	}
}

 生成xml文件如下

<dog xmlns="this is the default namespace">
   <xml>
      <id>001</id>
      <name>dog</name>
      <desc>lovely dog</desc>
   </xml>
   <color>yellow</color>
</dog>

 

Note:

1) 要使用MOXy特性必须添加jaxb.properties并发在要转化的模型对象的同级目录

2) package-info.java 可以指定同级目录的模型对象转化成xml文件的namespace信息

3) 可以通过XmlPath 指定最终生成的xml文件格式

4) 如果有继承，最终生成的xml可能会有xsi信息，可以通过添加@XmlTransient消除这部分信息