如何在编组和解组时将相同的值映射到jaxb中的两个不同字段 [英] how to map same value to two different fields in jaxb while marshalling and unmarshalling

问题描述

我有一个xml标签Hello，我的java中有一个类似下面的字段

I have a xml tag Hello for which there is a field like below in my java

类HelloWorld {
@XmlElement
私有字符串名称;
}

虽然解组成功将Hello值赋给name变量。现在我想从这个java对象创建一个新的xml （HelloWorld），我正在进行编组，但在这种情况下，我想要一个xml标签而不是我的xml。
如何在Jaxb中实现这一点？

While unmarshalling this successfully assigns Hello value to name variable.Now I want to create a new xml from THIS java object(HelloWorld) for which I am doing the marshalling but in this case I want a xml tag as instead of in my xml. How can I acheive this in Jaxb?

两个Xml都不在我的控制范围内，所以我无法更改标签名称

Both Xml are not in my control so I cannot change the tag name

编辑：

传入XMl - helloworld.xml

Incoming XMl - helloworld.xml

    <helloworld>
     <name>hello</name>
     </helloworld>

     @XmlRootElement(name="helloworld)
     class HelloWorld{

     @XmlElement(name="name")
     private String name;

      // setter and getter for name
     }

      JaxbContext context = JAXBContext.newInstance(HelloWorld.class);
      Unmarshaller un = conext.createUnmarshaller un();
      HelloWorld hw = un.unmarshal(new File("helloworld.xml"));
      System.out.println(hw.getName()); // this will print hello as <name> tag is mapped with name variable.

现在我想使用HelloWorld对象的这个hw对象来创建一个像下面的xml

Now I want to use this hw object of HelloWorld object to create a xml like below

    <helloworld>
     <name_1>hello</name_1>   // Note <name> is changed to <name_1>
    </helloworld>

我做不想创建像Helloworld这样的另一个类，并在该新类中声明变量name_1。我想重用这个HelloWorld class只是因为标签名称已被更改。

I do not want to create another class like Helloworld and declare a variable name_1 in that new class .I want to reuse this HelloWorld class only because just a tag name has been changed.

但我使用现有的HelloWorld类并尝试编组对象hw，如下所示

But I use existing HelloWorld class and try to marshal the object hw like below

    JaxbContext context = JAXBContext.newInstance(HelloWorld.class);
     Marshaller m = conext.createMarshaller();
     StringWriter writer = new StringWriter();
     m.marshal(hw,writer);
     System.out.println(writer.toString());

这将打印如下

  <helloworld>
<name>hello</name>
  </helloworld>

但我需要

  <helloworld>
<name_1>hello</name_1>   // Note <name> is changed to <name_1>
  </helloworld>

原因是解组前传入的xml和编组后的传出xml不在我的下面控制。

The reason for this is that the incoming xml before unmarshalling and the outgoing xml after marshalling is not under my control.

希望这能解释。

推荐答案

选项＃1 - 适用于所有JAXB实现

您可以使用XSLT转换将 JAXBSource 转换为您想要的XML：

Option #1 - Works with all JAXB Implementations

You could use a XSLT transform to transform a JAXBSource into the XML you want:

    // Create Transformer
    TransformerFactory tf = TransformerFactory.newInstance();
    StreamSource xslt = new StreamSource(
            "src/blog/jaxbsource/xslt/stylesheet.xsl");
    Transformer transformer = tf.newTransformer(xslt);

    // Source
    JAXBContext jc = JAXBContext.newInstance(Library.class);
    JAXBSource source = new JAXBSource(jc, catalog);

    // Result
    StreamResult result = new StreamResult(System.out);

    // Transform
    transformer.transform(source, result);

更多信息

• http://blog.bdoughan.com/2012/11/using-jaxb-with-xslt-to-produce-html.html

• http://blog.bdoughan.com/2012/11/using-jaxb-with-xslt-to-produce-html.html

注意：我是MOXy领导。

MOXy提供了一个映射文档扩展，可用于覆盖字段/属性级别的映射。这意味着您可以仅在注释上创建一个 JAXBContext ，然后根据带有XML的注释创建第二个 JAXBContext 覆盖。

MOXy provides a mapping document extension that you can use to override the mappings at the field/property level. This means you could create one JAXBContext on just the annotations, and then a second JAXBContext based on the annotations with an XML overrride.

更多信息

• < a href =http://blog.bdoughan.com/2010/12/extending-jaxb-representing-annotations.html =nofollow> http://blog.bdoughan.com/2010/12/extending- jaxb-represent-annotations.html

• http://blog.bdoughan.com/2010/12/extending-jaxb-representing-annotations.html

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