問題描述

我需要 unmarshall 未知 XML 內容的子集，使用該未編組的對象，我需要修改一些內容并重新綁定相同的 XML 內容(子集) 與原始 XML.

I have a requirement to unmarshall a subset of Unknown XML content, with that unmarshalled object, I need modify some contents and re-bind the same XML content(subset) with the Original XML.

輸入 XML 示例:

<Message>
    <x>
    </x>
    <y>
    </y>
    <z>
    </z>
    <!-- Need to unmarshall this content to "Content" - java Object -->
    <Content>
        <Name>Robin</Name>
        <Role>SM</Role>
        <Status>Active</Status>
    </Content>
.....
</Message>

需要單獨解組 <Content> 標記，保持其他 XML 部分相同.需要修改<Content>標簽中的元素，并將修改后的XML部分與原文綁定，如下圖:

Need to unmarshall the <Content> tag alone, by keeping the other XML part as same. Need to modify the elements in <Content> tag and bind the modified XML part with the original as shown below:

預期輸出 XML:

<Message>
    <x>
    </x>
    <y>
    </y>
    <z>
    </z>
    <!-- Need to unmarshall this content to "Content" - java Object -->
    <Content>
        <Name>Robin_123</Name>
        <Role>Senior Member</Role>
        <Status>1</Status>
    </Content>
.....
</Message>

我的問題:

1. 此要求的可能解決方案是什么?(除了 DOM 解析 - 因為 XML 網絡非常龐大)

1. What is the possible solution for this Requirement ? (Except DOM parsing - as XML contnet is very huge)

JAXB2.0 中是否有任何選項可以執行此操作?

Is there any option to do this in JAXB2.0 ?

請就此提出您的建議.

推薦答案

考慮使用 StAX API.

對于給定的示例，此代碼使用 Content 元素的根元素創建一個 DOM 文檔:

For the given sample, this code creates a DOM document with a root element of the Content element:

class ContentFinder implements StreamFilter {
  private boolean capture = false;

  @Override public boolean accept(XMLStreamReader xml) {
    if (xml.isStartElement() && "Content".equals(xml.getLocalName())) {
      capture = true;
    } else if (xml.isEndElement() && "Content".equals(xml.getLocalName())) {
      capture = false;
      return true;
    }
    return capture;
  }
}

XMLInputFactory inFactory = XMLInputFactory.newFactory();
XMLStreamReader reader = inFactory.createXMLStreamReader(inputStream);
reader = inFactory.createFilteredReader(reader, new ContentFinder());
Source src = new StAXSource(reader);
DOMResult res = new DOMResult();
TransformerFactory.newInstance().newTransformer().transform(src, res);
Document doc = (Document) res.getNode();

這可以是 作為 /transform/dom/DOMSource.html" rel="nofollow">DOMSource.

This can then be passed to JAXB as a DOMSource.

在輸出時重寫 XML 時可以使用類似的技術.

Similar techniques can be used when rewriting the XML on output.

JAXB 似乎不直接接受 StreamSource，至少在 Oracle 1.7 實現中是這樣.

JAXB doesn't seem to accept a StreamSource directly, at least in the Oracle 1.7 implementation.

這篇關于JAXB 解組未知 XML 內容的子集的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！