您可以通过
XmlAccessorType(XmlAccessType.FIELD)在get / set方法中使用逻辑并将逻辑放入其中来执行以下操作：
例
package forum8885011;import javax.xml.bind.annotation.*;@XmlRootElement@XmlAccessorType(XmlAccessType.FIELD)class Example { private static final String PROP1_DEFAULT = "default1"; private static final String PROP2_DEFAULT = "123"; @XmlElement(defaultValue=PROP1_DEFAULT) String prop1; @XmlElement(defaultValue=PROP2_DEFAULT) Integer prop2; public String getProp1() { if(null == prop1) { return PROP1_DEFAULT; } return prop1; } public void setProp1(String value) { if(PROP1_DEFAULT.equals(value)) { prop1 = null; } else { prop1 = value; } } public int getProp2() { if(null == prop2) { return Integer.valueOf(PROP2_DEFAULT); } return prop2; } public void setProp2(int value) { if(PROP2_DEFAULT.equals(String.valueOf(value))) { prop2 = null; } else { prop2 = value; } }}演示版
package forum8885011;import javax.xml.bind.*;public class Demo { public static void main(String[] args) throws Exception { JAXBContext jc = JAXBContext.newInstance(Example.class); Marshaller marshaller = jc.createMarshaller(); marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); Example example = new Example(); example.setProp1("default1"); example.setProp2(123); System.out.println(example.getProp1()); System.out.println(example.getProp2()); marshaller.marshal(example, System.out); example.setProp1("FOO"); example.setProp2(456); System.out.println(example.getProp1()); System.out.println(example.getProp2()); marshaller.marshal(example, System.out); }}输出量
default1123<?xml version="1.0" encoding="UTF-8" standalone="yes"?><example/>FOO456<?xml version="1.0" encoding="UTF-8" standalone="yes"?><example> <prop1>FOO</prop1> <prop2>456</prop2></example>
想要查询更多的信息
- http://blog.bdoughan.com/2011/06/using-jaxbs-xmlaccessortype-to.html
