JAXB解組列表

Question

我無法用JAXB解組簡單的元素列表。我進一步簡化了模型，仍然存在問題。

我有2個元素類，一個Classroom元素和一個Student元素。我曾經模仿他們在Java中象下面這樣：

@XmlRootElement(name = "classroom", namespace = "http://www.info.com/school/model") 
@XmlAccessorType(XmlAccessType.FIELD) 
public class Classroom { 
    @XmlElementWrapper(name = "students") 
    @XmlElement(name = "student", type = Student.class) 
    private List<Student> students; 

    public List<Student> getStudents() { 
     return students; 
    } 

    public void setStudents(List<Student> students) { 
     this.students = students; 
    } 
} 

@XmlAccessorType(XmlAccessType.FIELD) 
public class Student { 
    private String name; 
    private String gender; 
    private Integer age; 

    public String getName() { 
     return name; 
    } 

    public void setName(String name) { 
     this.name = name; 
    } 

    public String getGender() { 
     return gender; 
    } 

    public void setGender(String gender) { 
     this.gender = gender; 
    } 

    public Integer getAge() { 
     return age; 
    } 

    public void setAge(Integer age) { 
     this.age = age; 
    } 
} 

當我嘗試解編教室的元素，它是無法解組學生名單。例如，下面的代碼應該輸出到System out「學生數量是2」，但是當我運行它時，我得到「學生數量是：0」。

有人能夠指出我正確配置JAXB註釋的方向，以便我可以解組嗎？

我甚至在JAXB上下文中添加了一個toString方法調用，我可以看到Student類也列出了。

public static void main(String[] args) { 
     SimpleJaxbTestForLists sjtfl = new SimpleJaxbTestForLists(); 
     sjtfl.unmarshal("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><classroom xmlns=\"http://www.info.com/school/model\"><students><student><name>Test Student 1</name><gender>Male</gender><age>12</age></student><student><name>Test Student 2</name><gender>Female</gender><age>12</age></student></students></classroom>"); 

    } 

    public void unmarshal(String xmlContent) { 
     try { 
      JAXBContext jaxbContext = JAXBContext.newInstance(Classroom.class); 

      System.out.println(jaxbContext.toString()); 
      Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller(); 


      StringReader reader = new StringReader(xmlContent); 
      Classroom classroom = (Classroom) jaxbUnmarshaller.unmarshal(reader); 

      System.out.println("Number of Pupils is: " + classroom.getStudents().size()); 
     } catch (JAXBException ex) { 
      ex.printStackTrace(); 
     } 
    } 

Answer 1

由於XML文檔指定一個默認的命名空間，您可以利用封裝級@XmlSchema註釋映射名稱空間限定：

package-info.java

@XmlSchema(
    namespace = "http://www.info.com/school/model", 
    elementFormDefault = XmlNsForm.QUALIFIED) 
package example; 

import javax.xml.bind.annotation.XmlNsForm; 
import javax.xml.bind.annotation.XmlSchema; 

對於更多信息

您可以閱讀m有關JAXB和命名空間限定在我的博客礦石：

• http://blog.bdoughan.com/2010/08/jaxb-namespaces.html