插入XML文档（JAVA）的另一个XML文档的特定节点

Question

我有一个XML1：

<letterContent> 
    <key1>key1</key1> 
    <key2>key2</key2> 
    <type>456</type> 
    <object1>789</object1> 
    <effectiveDate>00</effectiveDate> 
    <expandedData /> 
</letterContent> 

...和XML 2：

<expandedData> 
    <rsnForReg> 
     <legacyTIN> 
      <asCurrent>leg123</asCurrent> 
     </legacyTIN> 
     <etpmTIN> 
      <asCurrent>etpm123</asCurrent> 
     </etpmTIN> 
     <regType> 
      <asCurrent/> 
     </regType> 
    </rsnForReg> 
</expandedData> 

我想插入XML 2使用JAVA在expandedData节点上创建XML 1文档。

最终XML1应该是这样的：

<letterContent> 
    <key1>key1</key1> 
    <key2>key2</key2> 
    <type>456</type> 
    <object1>789</object1> 
    <effectiveDate>00</effectiveDate> 
    <expandedData> 
     <rsnForReg> 
      <legacyTIN> 
       <asCurrent>leg123</asCurrent> 
      </legacyTIN> 
      <etpmTIN> 
       <asCurrent>etpm123</asCurrent> 
      </etpmTIN> 
      <regType> 
       <asCurrent/> 
      </regType> 
     </rsnForReg> 
    </expandedData> 
</letterContent> 

XML2插入XML1的expandedData节点上。有任何想法吗？我知道我需要构建一个循环遍历XML 2的递归函数，但不知道如何在java中实现它。

Answer 1

考虑使用XPath：

import static javax.xml.xpath.XPathConstants.*; 
import javax.xml.transform.TransformerFactory; 
import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamResult; 
import javax.xml.xpath.*; 
import org.w3c.dom.*; 
import org.xml.sax.InputSource; 

public class Xml2into1 { 
    public static void main(String[] args) throws Exception { 
    // read from files 
    InputSource xml1 = new InputSource("xml1.xml"); 
    InputSource xml2 = new InputSource("xml2.xml"); 
    // find the node to add to 
    XPath xpath = XPathFactory.newInstance() 
     .newXPath(); 
    Node expandedData1 = (Node) xpath.evaluate("//expandedData", xml1, NODE); 
    Document doc1 = expandedData1.getOwnerDocument(); 
    // insert the nodes 
    Node expandedData2 = (Node) xpath.evaluate("//expandedData", xml2, NODE); 
    expandedData1.getParentNode() 
     .replaceChild(doc1.adoptNode(expandedData2), expandedData1); 
    // print results 
    TransformerFactory.newInstance() 
     .newTransformer() 
     .transform(new DOMSource(doc1), new StreamResult(System.out)); 
    } 
}