java - JAXB 解码无法正常工作

Question

我正在尝试使用 JAXB 将 XML 转换为对象，我的 XML 如下所示:

<entityResource>
   <Item xsi:type="objectPermissionImpl">
      <permissionMask>0</permissionMask>
      <permissionRecipient xsi:type="roleImpl">
        <externallyDefined>false</externallyDefined>
        <roleName>ROLE_USER</roleName>
      </permissionRecipient>
      <URI>repo:/public/adhoc/topics/JSDiagnosticTopic</URI>
   </Item>
   <Item xsi:type="objectPermissionImpl">
      <permissionMask>0</permissionMask>
      <permissionRecipient xsi:type="roleImpl">
        <externallyDefined>false</externallyDefined>
        <roleName>ROLE_ADMINISTRATOR</roleName>
      </permissionRecipient>
      <URI>repo:/public/adhoc/topics/JSDiagnosticTopic</URI>
   </Item>
</entityResource>

所以我创建了 3 个 java 类:EntityResource.java、Item.java 和 PermissionRecipient.java，如下所示:

EntityResource.java

import java.util.List;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="entityResource")
public class EntityResource {

    List<Item> ls_Item;

    public EntityResource() {
    }

    public List<Item> getLs_Item() {
        return ls_Item;
    }

    @XmlElement(name="Item")
    public void setLs_Item(List<Item> ls_Item) {
        this.ls_Item = ls_Item;
    }

    @Override
    public String toString() {
        return "EntityResource [ls_Item=" + ls_Item + "]";
    }

}

Item.java

package model;

import java.util.List;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Item")
public class Item {

    int permissionMask;
    List<PermissionRecipient> ls_permissionRecipient;
    String URI;

    public Item() {

    }

    public int getPermissionMask() {
        return permissionMask;
    }

    @XmlElement(name="permissionMask")
    public void setPermissionMask(int permissionMask) {
        this.permissionMask = permissionMask;
    }

    public List<PermissionRecipient> getLs_permissionRecipient() {
        return ls_permissionRecipient;
    }

    @XmlElement(name="permissionRecipient")
    public void setLs_permissionRecipient(
            List<PermissionRecipient> ls_permissionRecipient) {
        this.ls_permissionRecipient = ls_permissionRecipient;
    }

    public String getURI() {
        return URI;
    }

    @XmlElement(name="URI")
    public void setURI(String uRI) {
        URI = uRI;
    }

    @Override
    public String toString() {
        return "Item [permissionMask=" + permissionMask
                + ", ls_permissionRecipient=" + ls_permissionRecipient
                + ", URI=" + URI + "]";
    }





}

PermissionRecipient.java

package model;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="permissionRecipient")
public class PermissionRecipient {

    String roleName;
    boolean externallyDefined;

    public PermissionRecipient() {

    }

    public boolean isExternallyDefined() {
        return externallyDefined;
    }

    @XmlAttribute(name="externallyDefined")
    public void setExternallyDefined(boolean externallyDefined) {
        this.externallyDefined = externallyDefined;
    }

    public String getRoleName() {
        return roleName;
    }

    @XmlAttribute(name="roleName")
    public void setRoleName(String rolename) {
        this.roleName = rolename;
    }

    @Override
    public String toString() {
        return "PermissionRecipient [externallyDefined=" + externallyDefined
                + ", roleName=" + roleName + "]";
    }


}

一切正常，我得到一个包含 Item 的 EntityResource 对象，但是 EntityResource 的 Item 属性的 permissionRecipient 属性不包含他的属性(roleName 和 externallyDefined)!

我的解码代码在这里:

JAXBContext jaxbContext = JAXBContext
                    .newInstance(EntityResource.class);
            Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
            EntityResource resourceDescriptors = (EntityResource) jaxbUnmarshaller
                    .unmarshal(conn.getInputStream());// conn is an HttpURLConnection

Item 的toString() 函数返回了这个结果:

[Item 
[permissionMask=0, 
permissionRecipient=PermissionRecipient [externallyDefined=false, roleName=null], 
URI=repo:/public/adhoc/topics/JSDiagnosticTopic], 

Item 
[permissionMask=0, 
permissionRecipient=PermissionRecipient [externallyDefined=false, roleName=null], 
URI=repo:/public/adhoc/topics/JSDiagnosticTopic]]

正如您在每个项目中标记的那样，[externallyDefined=false, roleName=null]，为什么？我犯了什么错误？谢谢，如果这里有人可以帮助我解决它，最好的问候。

Answer 1

您将 roleName 和 externallyDefined 映射到 @XmlAttribute 而不是 @XmlElement。

调试提示

当您的对象模型未按预期解码时，填充它并将其编码为 XML，然后将输出与您的输入进行比较。