04_jaxb处理bean和xml

用于接口接收到的是xml报文，需转成bean处理。待处理完逻辑，把相应的bean再转成xml报文

//bean
@lombok
@XmlAccessorType(XmlAccessType.FIELD)
public class Head {
    private String fromId;
    private String systemId;
    public Head(String fromId, String systemId) {
        this.fromId = fromId;
        this.systemId = systemId;
    }
}

@lombok
@XmlAccessorType(XmlAccessType.FIELD)
public class Body {
    private String code;
    private String msg;
    public Body(String code, String msg) {
        this.code = code;
        this.msg = msg;
    }
}

@lombok
@XmlRootElement(name = "service")
@XmlAccessorType(XmlAccessType.FIELD)
public class Bean {
    @XmlElement(name="head")
    private Head head;
    @XmlElement(name="body")
    private Body body;
    public Bean(Head head, Body body) {
        this.head = head;
        this.body = body;
    }
}

//监听器 实体属性为null则转为""生成标签
class MarshallerListener extends Marshaller.Listener{
    public static final String BLANK_CHAR = "";
    @Override
    public void beforeMarshal(Object source) {
        super.beforeMarshal(source);
        Field[] fields = source.getClass().getDeclaredFields();
        for (Field f : fields) {
            f.setAccessible(true);
            try {
                if ((f.getType() == String.class||f.getType() ==Integer.class||f.getType()==Double.class||f.getType()== List.class)&& f.get(source) == null) {
                    f.set(source, BLANK_CHAR);
                }
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
    }
}

//测试
public class Test {
    public static void main(String[] args) throws JAXBException {
        System.out.println("==========bean转xml===========");
        Head head = new Head("xt1","xitong1");
        Body body = new Body("000020","成功");
        Bean bean = new Bean(head,body);
        
        JAXBContext  context = JAXBContext.newInstance(Bean.class);
        Marshaller marshaller = context.createMarshaller();
        StringWriter stringWriter = new StringWriter();
        marshaller.setListener(new MarshallerListener());//如属性为null,不需要转成标签，则省略此行代码
        marshaller.marshal(bean,stringWriter);
        String xml = stringWriter.toString();
        System.out.println("xml："+xml );
        
        System.out.println("==========xml转bean===========");
        Unmarshaller unmarshaller = context.createUnmarshaller();
        Bean bean = (Bean)unmarshaller.unmarshal(new StringReader(xml));
        Head head = bean.getHead();Body body = bean.getBody();
     }   
}