//xml轉換成bean
    public static RequestXML parseToBean(String xmlstr)  {  
        RequestXML requestXml = null;  
        try {  
            JAXBContext jaxbContext = JAXBContext.newInstance(RequestXML.class);  
            Unmarshaller um = jaxbContext.createUnmarshaller();  
            requestXml = (RequestXML)um.unmarshal(new ByteArrayInputStream(xmlstr.getBytes()));  
        } catch (JAXBException e) {  
            e.getMessage();  
        }  
        return requestXml;  
    }

    //bean 轉換成 xml
    private static String parseToXml(Object javaBean) throws Exception{
        JAXBContext context = JAXBContext.newInstance(xmlBean.getClass());
        Marshaller m = context.createMarshaller();
        
        StringWriter sw = new StringWriter();
        m.marshal(javaBean,sw);
        
        return sw.toString();
    }

<?xml version="1.0" encoding="utf-8"?>
<bean id="10" code="xm1000x">
    <name>x.m<name>
    
    <levels>
        <level key="1">none</level>
        <level key="2">nothing</level>
    </levels>
    
    <extras>
        <extra>
            <type>1</type>
            <content>xx.mm.xx</content>
        </extra>
        <extra>
            <type>2</type>
            <content>xx.mm.xx</content>
        </extra>
    </extras>
    
</bean>        

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



@XmlRootElement
public class Level {
    
    private Integer Key;
    private String value;
    
    public Level(){}
    
    @XmlAttribute(name="key")
    public Integer getKey() {
        return Key;
    }

    @XmlValue
    public String getValue() {
        return value;
    }

    public void setKey(Integer key) {
        Key = key;
    }

    public void setValue(String value) {
        this.value = value;
    }
    
    
}

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


@XmlRootElement
public class Extra {
    private String type;
    private String content;
    
    public Extra(){}

    @XmlElement
    public String getType() {
        return type;
    }

    @XmlElement
    public String getContent() {
        return content;
    }

    public void setType(String type) {
        this.type = type;
    }

    public void setContent(String content) {
        this.content = content;
    }
    
    
}