默认情况下，只有public 属性才会绑定到xml元素

package com.test;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="MyRootElement")
public class AccessorType {
    
    public String name;
    private String address;
    
    public void setName(String name) {
        this.name = name;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public static void main(String[] args) throws Exception {
        AccessorType root = new AccessorType();
        root.setName("ROSS");
        root.setAddress("GZ");
        
        JAXBContext context = JAXBContext.newInstance(AccessorType.class);
        Marshaller m = context.createMarshaller();
        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        m.marshal(root, System.out);
    }   
}

输出如下，可以看到只有public的name被绑定了，而private的address没有。

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<MyRootElement>
    <name>ROSS</name>
</MyRootElement>

使用@XmlAccessorType(XmlAccessType.FIELD)可以让所有member都被绑定

package com.test;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="MyRootElement")
@XmlAccessorType(XmlAccessType.FIELD)
public class AccessorType {
    
    public String name;
    private String address;
    
    public void setName(String name) {
        this.name = name;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public static void main(String[] args) throws Exception {
        AccessorType root = new AccessorType();
        root.setName("ROSS");
        root.setAddress("GZ");
        
        JAXBContext context = JAXBContext.newInstance(AccessorType.class);
        Marshaller m = context.createMarshaller();
        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        m.marshal(root, System.out);
    }
}

输出

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<MyRootElement>
    <name>ROSS</name>
    <address>GZ</address>
</MyRootElement>

除了绑定member，还可以用@XmlAccessorType(XmlAccessType.PROPERTY)绑定getter/setter 对

package com.test;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="MyRootElement")
@XmlAccessorType(XmlAccessType.PROPERTY)
public class AccessorType {
    
    public String name;
    private String address;
    
    public void setName(String name) {
        this.name = name;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public static void main(String[] args) throws Exception {
        AccessorType root = new AccessorType();
        root.setName("ROSS");
        root.setAddress("GZ");
        
        JAXBContext context = JAXBContext.newInstance(AccessorType.class);
        Marshaller m = context.createMarshaller();
        m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        m.marshal(root, System.out);
    }
    public String getNameAddress() {
        return name + " " + address;
    }
    public void setNameAddress(String nameAddress) {}
}

输出

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<MyRootElement>
    <nameAddress>ROSS GZ</nameAddress>
</MyRootElement>