blocks|key|1004445|text|使用JAXB的好处是它是一个具有多个实现的标准运行时(就像JPA一样)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1004446|如果您使用JAXB+(MOXy)，那么您可以使用许多扩展来处理EclipseLink实体，包括双向关系。这是使用MOXy+@XmlInverseReference注释完成的。它在编组上的行为类似于@XmlTransient，并在解组时填充目标到源的关系。|1004447|http://wiki.eclipse.org/EclipseLink/Examples/MOXy/JPA/Relationships|offset|length|1004448|@Entity+
@XmlRootElement+
public+class+Contact+{+

++++@Id+
++++private+Long+contactId;+

++++@OneToMany(mappedBy+=+"contact")+
++++private+List<ContactAddress>+addresses;+

...+

}+

@Entity+
@XmlRootElement+
public+class+ContactAddress+{+

++++@Id+
++++private+Long+contactAddressId;+

++++@ManyToOne+
++++@JoinColumn(name+=+"contact_id")+
++++@XmlInverseReference(mappedBy="addresses")
++++private+Contact+contact;+

++++private+String+address;+

...+

}+|code-block|syntax|javascript|1004449|还可以使用其他扩展，包括对组合键和嵌入式键类的支持。|1004450|要指定EcliseLink+MOXy+JAXB实现，您需要在模型类(即契约)中包含一个jaxb.properties文件，其中包含以下条目：|1004451|javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory|1004452|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|1V|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|11|8|@]|9|@$F|12|G|13|1|14]]|A|$]]|$1|H|3|I|5|J|7|15|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|16|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|17|8|@]|9|@]|A|$]]|$1|Q|3|R|5|J|7|18|8|@]|9|@]|A|$K|L]]|$1|S|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|E]]]]

The good thing about using JAXB is that it is a standard runtime with multiple implementations (just like JPA).

If you use EclipseLink JAXB (MOXy) then you have many extensions available to you for handling JPA entities including bi-directional relationships. This is done using the MOXy @XmlInverseReference annotation. It acts similar to @XmlTransient on the marshal and populates the target-to-source relationship on the unmarshal.

<a href="http://wiki.eclipse.org/EclipseLink/Examples/MOXy/JPA/Relationships" rel="noreferrer">http://wiki.eclipse.org/EclipseLink/Examples/MOXy/JPA/Relationships</a>

<pre><code>@Entity 
@XmlRootElement 
public class Contact { 

 @Id 
 private Long contactId; 

 @OneToMany(mappedBy = "contact") 
 private List&lt;ContactAddress&gt; addresses; 

... 

} 

@Entity 
@XmlRootElement 
public class ContactAddress { 

 @Id 
 private Long contactAddressId; 

 @ManyToOne 
 @JoinColumn(name = "contact_id") 
 @XmlInverseReference(mappedBy="addresses")
 private Contact contact; 

 private String address; 

... 

} 
</code></pre>

Other extensions are available including support for composite keys &amp; embedded key classes.

To specify the EcliseLink MOXy JAXB implementation you need to include a jaxb.properties file in with your model classes (i.e. Contract) with the following entry:

<pre><code>javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
</code></pre>

blocks|key|1218898|text|看看这个教程：Mapping+cyclic+references+to+XML+by+jaxb|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1218899|我使用它，它工作得很好:)|1218900|entityMap|0|LINK|mutability|MUTABLE|url|http://jaxb.java.net/guide/Mapping_cyclic_references_to_XML.html^0|7|W|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

just look at this tutorial : <a href="http://jaxb.java.net/guide/Mapping_cyclic_references_to_XML.html" rel="nofollow noreferrer">Mapping cyclic references to XML</a> by jaxb

I use it an it works well :)

blocks|key|1218963|text|XMLTransient几乎总是在循环中工作。可能的情况是，您在字段级别上具有XMLTransient，但尚未将XMLAccessorType指定为XmlAccessType.Field。如果您不指定任何内容，则缺省值为XmlAccessType.Property+-或您的getters。我遇到过Jaxb从getter中挑选xml元素的经验，因为我错过了访问器类型注释，但仍然可以很好地工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1218964|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

XMLTransient almost always works for cycles. It might be a possibility that you have XMLTransient on the field level but you have not specified XMLAccessorType to be XmlAccessType.Field. If you don't specify anything the default is XmlAccessType.Property - or your getters. I have experienced Jaxb picking xml elements from getters from a class that I missed the accessor type annotations on and still work perfectly fine.

blocks|key|1004601|text|我们也可以使用XStream库，我在一个项目中尝试过，其中JAXB给出了循环错误，但XStream成功地处理了它|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1004602|entityMap|0|LINK|mutability|MUTABLE|url|http://xstream.codehaus.org/tutorial.html^0|7|7|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

We can use <a href="http://xstream.codehaus.org/tutorial.html" rel="nofollow">XStream</a> library as well, I tried it one project where JAXB was giving cyclic error but XStream handled it successfully

I have an object graph that contains a cycle. How do I get JAXB to handle this? I tried using the <code>@XmlTransient</code> annotation in the child class but the JAXB marshaller still detects the cycle.

<pre><code>@Entity
@XmlRootElement
public class Contact {

 @Id
 private Long contactId;

 @OneToMany(mappedBy = "contact")
 private List&lt;ContactAddress&gt; addresses;

...

}

@Entity
@XmlRootElement
public class ContactAddress {

 @Id
 private Long contactAddressId;

 @ManyToOne
 @JoinColumn(name = "contact_id")
 private Contact contact;

 private String address;

...

}
</code></pre>

JAXB Mapping cyclic references to XML

我有一个包含循环的对象图。如何让JAXB处理这个问题？我尝试在子类中使用@XmlTransient注释，但是JAXB marshaller仍然检测到这个循环。@Entity@XmlRootElementpublic class Contact {    @Id    private Long contactId;   ...

问JAXB将循环引用映射到XML
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