當使用工廠方法檢索到一個值時，從JAXB創建xml

Question

我有一個UUID類，我從靜態工廠方法（如 ）獲取uuid UUIDGenerator.getInstance（）。getUuid（）;

我有另一個有這些UUids作爲列表的類。

class Artifact 
    { 
     Uuid uuid; 
     setUuid(Uuid uuid) 
     { 
     this.uuid = uuid; 
     } 

     Uuid getUuid() 
     { 
     return this.uuid; 
     } 
    } 


Class ArtifactData 
{ 
    private List<Artifact> artifacts; 
    //setter for list 
    // getter for list 

} 

我想XML以創建爲

<ArtifactData> 
<AssociatedArtifactList> 
<ArtifactUuid>#some value<ArtifactUuid> 
</AssociatedArtifactList> 
</ArtifactData> 

如何創建這個XML列JAXB註釋。它抱怨說沒有Uuid的公共構造函數，因爲它是用工廠方法構建的。

編輯：Uuid和Uuid發生器不能被修改。他們在JAR中。這是我到目前爲止所嘗試的

public class Artifact 
{ 
    @XmlJavaTypeAdapter(ArtifactUuidAdapter.class) 
    private Uuid uuid; 


    public Uuid getUuid() 
    { 
     return uuid; 
    } 

    public void setUuid(Uuid uuid) 
    { 
     this.uuid = uuid; 
    } 

} 

@XmlRootElement 
public class ArtifactData 
{ 
    private List<Artifact> associatedArtifactList; 
    public List<Artifact> getArtifacts() 
    { 
     return associatedArtifactList; 
    } 

    @XmlElementWrapper(name="associatedArtifactList") 
    @XmlElement(name = "artifactUuid") 
    public void setArtifacts(List<Artifact> artifacts) 
    { 
     this.associatedArtifactList = artifacts; 
    } 
} 


public class ArtifactUuidAdapter extends XmlAdapter<Uuid, String> 
{ 
    @Override 
    public Uuid marshal(String uuid) throws Exception 
    { 
     return Uuid.getInstance(uuid); 
    } 

    @Override 
    public String unmarshal(Uuid uuid) throws Exception 
    { 
     return uuid.getData(); 
    } 
} 

我仍然收到一個錯誤，稱爲no arg默認構造函數丟失。

Answer 1

@XmlType註釋允許您配置工廠類和方法。您的問題中描述的工廠類不完全符合API要求，但您可以輕鬆地爲其創建適配器。

UUIDGeneratorAdapter

下面的類會適應你的工廠類的東西，一個JAXB（JSR-222）實現可以利用。

public class UUIDGeneratorAdapter { 

    public static Uuid getUuid() { 
     return UUIDGenerator.getInstance().getUuid(); 
    } 

} 

UUID

下面是你如何通過@XmlType註釋配置工廠類的實例。

import javax.xml.bind.annotation.XmlType; 

@XmlType(factoryClass=UUIDGeneratorWrapper.class, factoryMethod="getUuid") 
public class Uuid { 

    // ... 

} 

更多信息

• http://blog.bdoughan.com/2011/06/jaxb-and-factory-methods.html