blocks|key|888905|text|您可以删除该文件并创建一个新文件。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|888906|Document+doc+=+DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(
++++new+InputSource("data.xml"));

XPath+xpath+=+XPathFactory.newInstance().newXPath();
NodeList+nodes+=+(NodeList)+xpath.evaluate("//employee/name[text()='old']",+doc,
++++XPathConstants.NODESET);

for+(int+idx+=+0;+idx+<+nodes.getLength();+idx%2B%2B)+{
++nodes.item(idx).setTextContent("new+value");
}

Transformer+xformer+=+TransformerFactory.newInstance().newTransformer();
xformer.transform(new+DOMSource(doc),+new+StreamResult(new+File("data_new.xml")));|code-block|syntax|javascript|888907|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You can delete the file and create a new one. 

<pre><code>Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(
 new InputSource("data.xml"));

XPath xpath = XPathFactory.newInstance().newXPath();
NodeList nodes = (NodeList) xpath.evaluate("//employee/name[text()='old']", doc,
 XPathConstants.NODESET);

for (int idx = 0; idx &lt; nodes.getLength(); idx++) {
 nodes.item(idx).setTextContent("new value");
}

Transformer xformer = TransformerFactory.newInstance().newTransformer();
xformer.transform(new DOMSource(doc), new StreamResult(new File("data_new.xml")));
</code></pre>

blocks|key|888609|text|XPath用于选择XML的一部分，document.It不支持更新。但是，由于它返回DOM对象(元素，如果内存有效，或者可能是节点)，因此您可以使用DOM方法来更改文档。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|888610|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|$]]

XPath is used to select parts of an XML document.It has no provision for updating. But since it returns DOM objects (Elements, if memory serves, or maybe Nodes) you can then use DOM methods for altering the document.

blocks|key|888723|text|考虑使用XQuery更新而不是XPath。这使您可以编写|type|unstyled|depth|inlineStyleRanges|entityRanges|data|888724|replace+value+of+node+//PersonList/Person[2]/Name+with+"Anonymous"|code-block|syntax|javascript|888725|这比使用Java+DOM+API容易得多。|888726|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Consider using XQuery Update instead of XPath. This allows you to write

<pre><code>replace value of node //PersonList/Person[2]/Name with "Anonymous"
</code></pre>

This is much easier than using the Java DOM API.

blocks|key|671757|text|我已经创建了一个使用XPATH创建/更新xml的小项目：https://github.com/shenghai/xmodifier更改xml的代码如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|671758|Document+document+=+readDocument("personList.xml");
XModifier+modifier+=+new+XModifier(document);
modifier.addModify("//PersonList/Person[2]/Name",+"newName");
modifier.modify();|code-block|syntax|javascript|671759|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/shenghai/xmodifier^0|S|11|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

I've created a small project for using XPATH to create/update XML:
<a href="https://github.com/shenghai/xmodifier" rel="nofollow">https://github.com/shenghai/xmodifier</a>
the code to change your xml is like:

<pre><code>Document document = readDocument("personList.xml");
XModifier modifier = new XModifier(document);
modifier.addModify("//PersonList/Person[2]/Name", "newName");
modifier.modify();
</code></pre>

blocks|key|888978|text|这是一个非常酷的函数，您可以使用其xpath修改任何XML文档的任何标记值。您需要传递三个参数xml、xpathExpression和newValue，它将以String形式返回带有修改后的值的XML文件。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|888979|如果您希望将XML作为文件传递，则需要相应地更改函数。但逻辑将是相同的。|888980|+public+String+updateXML(String+xml,+String+xpathExpression,+String+newValue)
+{
++++try+{
++++++++//Creating+document+builder
++++++++DocumentBuilderFactory+builderFactory+=+DocumentBuilderFactory.newInstance();
++++++++DocumentBuilder+builder+=+builderFactory.newDocumentBuilder();
++++++++Document+document+=+builder.parse(new+org.xml.sax.InputSource(new+StringReader(xml)));
++++++
++++++++//Evaluating+xpath+expression+using+Element
++++++++XPath+xpath+=+XPathFactory.newInstance().newXPath();
++++++++Element+element+=+(Element)xpath.evaluate(xpathExpression,+document,+XPathConstants.NODE);
++++++++
++++++++//Setting+value+in+the+text
++++++++element.setTextContent(value);

++++++++//Transformation+of+document+to+xml
++++++++StringWriter+stringWriter+=+new+StringWriter();
++++++++Transformer+xformer+=+TransformerFactory.newInstance().newTransformer();
++++++++xformer.transform(new+DOMSource(document),+new+StreamResult(stringWriter));

++++++++xml+=+stringWriter.toString();
++++++++}+
++++++++catch+(Exception+e)+
++++++++{
+++++++++++e.printStackTrace();
++++++++}
++++return+xml;
}|code-block|syntax|javascript|888981|entityMap^0|H|5|1B|3|1F|F|1V|8|27|6|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|N|$]]

This is a super cool function where you can able to modify any tag value for any XML document using its <code>xpath</code>. You need to pass three arguments <code>xml</code>,<code>xpathExpression</code> and <code>newValue</code> and it returns the XML file as <code>String</code> with modified value.
If you want to pass XML as file, you need to change the function accordingly. But the logic will be same.
<pre><code> public String updateXML(String xml, String xpathExpression, String newValue)
 {
 try {
 //Creating document builder
 DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
 DocumentBuilder builder = builderFactory.newDocumentBuilder();
 Document document = builder.parse(new org.xml.sax.InputSource(new StringReader(xml)));
 
 //Evaluating xpath expression using Element
 XPath xpath = XPathFactory.newInstance().newXPath();
 Element element = (Element)xpath.evaluate(xpathExpression, document, XPathConstants.NODE);
 
 //Setting value in the text
 element.setTextContent(value);

 //Transformation of document to xml
 StringWriter stringWriter = new StringWriter();
 Transformer xformer = TransformerFactory.newInstance().newTransformer();
 xformer.transform(new DOMSource(document), new StreamResult(stringWriter));

 xml = stringWriter.toString();
 } 
 catch (Exception e) 
 {
 e.printStackTrace();
 }
 return xml;
}
</code></pre>

blocks|key|671820|text|下面是使用API更改内容的代码...+vtd-xml的独特之处在于它是唯一提供增量更新功能的vtd-xml。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|671821|import+com.ximpleware.*;
import+java.io.*;

public+class+changeName+{
++++public++static++void+main(String+s[])+throws+VTDException,java.io.UnsupportedEncodingException,java.io.IOException{
++++++++VTDGen+vg+=+new+VTDGen();
++++++++if+(!vg.parseFile("input.xml",+false))
++++++++++++return;
++++++++VTDNav+vn+=+vg.getNav();
++++++++AutoPilot+ap+=+new+AutoPilot(vn);
++++++++XMLModifier+xm+=+new+XMLModifier(vn);
++++++++ap.selectXPath("//PersonList/Person[2]");
++++++++int+i=0;
++++++++while((i=ap.evalXPath())!=-1){
++++++++++++if+(vn.toElement(VTDNav.FIRST_CHILD,"Name")){
+++++++++++++++++int+k=vn.getText();
+++++++++++++++++if+(i!=-1)
++++++++++++++++++++xm.updateToken(k,+"Jonathan");+
+++++++++++++++++vn.toElement(VTDNav.PARENT);
++++++++++++}
++++++++++++if+(vn.toElement(VTDNav.FIRST_CHILD,"Age")){
+++++++++++++++++int+k=vn.getText();
+++++++++++++++++if+(i!=-1)
++++++++++++++++++++xm.updateToken(k,+"42");+
+++++++++++++++++vn.toElement(VTDNav.PARENT);
++++++++++++}
++++++++}
++++++++xm.output("new.xml");
++++}
}|code-block|syntax|javascript|671822|entityMap|0|LINK|mutability|MUTABLE|url|http://vtd-xml.sf.net/|1|http://recipp.ipp.pt/bitstream/10400.22/1847/1/ART_BrunoOliveira_2013.pdf^0|J|7|0|1A|7|1|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]|$A|W|B|X|1|Y]]|C|$]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]|Q|$5|L|M|N|C|$O|R]]]]

Here is the code to change the content with <a href="http://recipp.ipp.pt/bitstream/10400.22/1847/1/ART_BrunoOliveira_2013.pdf" rel="nofollow noreferrer">vtd-xml</a>... <a href="http://vtd-xml.sf.net" rel="nofollow noreferrer">vtd-xml</a> is unique in that it is the only API that offers incremental update capability. 

<pre><code>import com.ximpleware.*;
import java.io.*;

public class changeName {
 public static void main(String s[]) throws VTDException,java.io.UnsupportedEncodingException,java.io.IOException{
 VTDGen vg = new VTDGen();
 if (!vg.parseFile("input.xml", false))
 return;
 VTDNav vn = vg.getNav();
 AutoPilot ap = new AutoPilot(vn);
 XMLModifier xm = new XMLModifier(vn);
 ap.selectXPath("//PersonList/Person[2]");
 int i=0;
 while((i=ap.evalXPath())!=-1){
 if (vn.toElement(VTDNav.FIRST_CHILD,"Name")){
 int k=vn.getText();
 if (i!=-1)
 xm.updateToken(k, "Jonathan"); 
 vn.toElement(VTDNav.PARENT);
 }
 if (vn.toElement(VTDNav.FIRST_CHILD,"Age")){
 int k=vn.getText();
 if (i!=-1)
 xm.updateToken(k, "42"); 
 vn.toElement(VTDNav.PARENT);
 }
 }
 xm.output("new.xml");
 }
}
</code></pre>

I have an XML document, and an XPath expression for that doc. I have to update the doc by using XPath at runtime.

How can I do this using Java?

The below is my xml:

<pre><code>&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
&lt;PersonList&gt;
 &lt;Person&gt;
 &lt;Name&gt;Sonu Kapoor&lt;/Name&gt;
 &lt;Age&gt;24&lt;/Age&gt;
 &lt;Gender&gt;M&lt;/Gender&gt;
 &lt;PostalCode&gt;54879&lt;/PostalCode&gt;
 &lt;/Person&gt;
 &lt;Person&gt;
 &lt;Name&gt;Jasmin&lt;/Name&gt;
 &lt;Age&gt;28&lt;/Age&gt;
 &lt;Gender&gt;F&lt;/Gender&gt;
 &lt;PostalCode&gt;78745&lt;/PostalCode&gt;
 &lt;/Person&gt;
 &lt;Person&gt;
 &lt;Name&gt;Josef&lt;/Name&gt;
 &lt;Age&gt;232&lt;/Age&gt;
 &lt;Gender&gt;F&lt;/Gender&gt;
 &lt;PostalCode&gt;53454&lt;/PostalCode&gt;
 &lt;/Person&gt;
&lt;/PersonList&gt;
</code></pre>

I have to change the values of name and age under <code>//PersonList/Person[2]/Name</code>.

How to update XML using XPath and Java

Java

我有一个XML文档，以及该文档的XPath表达式。我必须在运行时使用XPath更新文档。我如何使用Java来做这件事？下面是我的xml：<?xml version="1.0" encoding="ISO-8859-1"?><PersonList> <Person> <Name>Sonu Kapoor</Name> <Age>24</Age> <Gen

问如何使用XPath和Java更新XML
EN

回答 6

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何使用XPath和Java更新XMLEN

回答 6

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何使用XPath和Java更新XML
EN