排除在外节点列表<X>

Question

public class Group { 
    //many other fields 
    public List<Person> persons; 
} 

public class Person { 
    public String name; ... 
} 

的编组当我我marhsal想了一堆人节点：

<person> 
    <name>..</name> 
</person> 
<person> 
    <name>..</name> 
</person> 

，而不是这样的：（与人的节点作为一个人的节点儿童）

<persons> 
    <person> 
     <name>..</name> 
    </person> 
    <person> 
     <name>..</name> 
    </person> 
<persons> 

我该如何做到这一点？

Answer 1

UPDATE

如果你指的是persons作为分组元素，而不是根元素JAXB (JSR-222)实现默认不添加。

组（无分组元素）

package forum13305973; 

import java.util.*; 
import javax.xml.bind.annotation.*; 

@XmlRootElement 
public class Group { 
    //many other fields 
    @XmlElement(name="person") 
    public List<Person> persons = new ArrayList<Person>(); 
} 

人

package forum13305973; 

public class Person { 
    public String name; 
} 

演示

package forum13305973; 

import javax.xml.bind.*; 

public class Demo { 

    public static void main(String[] args) throws Exception { 
     JAXBContext jc = JAXBContext.newInstance(Group.class); 

     Group group = new Group(); 

     Person person1 = new Person(); 
     person1.name = "Jane"; 
     group.persons.add(person1); 

     Person person2 = new Person(); 
     person2.name = "John"; 
     group.persons.add(person2); 

     Marshaller marshaller = jc.createMarshaller(); 
     marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); 
     marshaller.marshal(group, System.out); 
    } 

} 

输出

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
<group> 
    <person> 
     <name>Jane</name> 
    </person> 
    <person> 
     <name>John</name> 
    </person> 
</group> 

---

组（分组元素）

您需要添加一个@XmlElementWrapper注解获得分组元素

package forum13305973; 

import java.util.*; 

import javax.xml.bind.annotation.*; 

@XmlRootElement 
public class Group { 
    //many other fields 
    @XmlElementWrapper 
    @XmlElement(name="person") 
    public List<Person> persons = new ArrayList<Person>(); 
} 

输出（带分组元素）

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
<group> 
    <persons> 
     <person> 
      <name>Jane</name> 
     </person> 
     <person> 
      <name>John</name> 
     </person> 
    </persons> 
</group> 

---

原来的答案

你可以做到以下几点：

JAXBContext jc = JAXBContext.newInstance(Person.class); 
    Marshaller marshaller = jc.createMarshaller(); 
    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); // format output 
    marshaller.setProperty(Marshaller.JAXB_FRAGMENT, true); // remove header 

    for(Person person : group.persons) { 
     marshaller.marshal(person, System.out); 
    }