使用 Java 中的 XPath 解析 XML - 使用 Java 中的 Xpath 和 NodeList 从 XML 文件中获取数据
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/5673708/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Parsing XML with XPath in Java - Get data from XML file with Xpath and NodeList in Java
提问by Ali Ben Messaoud
I have this xml file and I want to get some values with Xpath.
我有这个 xml 文件，我想用 Xpath 获取一些值。
The half of job is done but I get some trouble in the last part of file(States Node)
一半的工作已经完成，但我在文件的最后一部分（状态节点）遇到了一些麻烦
<?xml version="1.0" encoding="UTF-8"?>
<favoris>
<workflow codewf="wf1000">
<information>
<title>wf1</title>
<desc>description 1</desc>
<nberState>2</nberState>
<text>text text text text text text text</text>
</information>
<states>
<state id="1" IDemployee="2">description1</state>
<state id="2" IDemployee="3">description2</state>
</states>
</workflow>
<workflow codewf="wf2000">
<information>
<title>wf2</title>
<desc>description 2</desc>
<nberState>3</nberState>
<text>text text text text text text text</text>
</information>
<states>
<state id="1" IDemployee="3">description1</state>
<state id="2" IDemployee="2">description2</state>
<state id="3" IDemployee="4">description2</state>
</states>
</workflow>
</favoris>
And here the java code: package myxml;
这里是java代码：package myxml;
import java.io.FileReader;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
public class xmlParty {
public static void main(String[] args) throws Exception {
XPathFactory factory = XPathFactory.newInstance();
XPath xPath = factory.newXPath();
NodeList favoris = (NodeList) xPath.evaluate("/favoris/workflow[@codewf='wf1000']",
new InputSource(new FileReader("a.xml")),
XPathConstants.NODESET);
for (int i = 0; i < favoris.getLength(); i++) {
Element workflow = (Element) favoris.item(i);
String title = xPath.evaluate("information/title", workflow);
String desc_w = xPath.evaluate("information/desc", workflow);
String nberState = xPath.evaluate("information/nberState", workflow);
String text = xPath.evaluate("information/text", workflow);
System.out.println(workflow.getAttribute("codewf") +" "+title + " " + desc_w + " " + nberState + " " + text );
NodeList States = (NodeList)xPath.evaluate("states/state", workflow, XPathConstants.NODESET);
System.out.println(States.getLength());
for (int k = 0; k < States.getLength(); k++) {
String desc_state = xPath.evaluate("states/state", workflow);
System.out.println(desc_state );
}
}
}
}
and the output will be :
输出将是：
First example
第一个例子
wf1000 wf1 description 1 2 text text text text text text text
2
description1
description1
Second example
第二个例子
wf2000 wf2 description 2 3 text text text text text text text
3
description1
description1
description1
Looking at the state with ID 2, the text is description2not description1.
I think the parser don't move to the second child and it always still at the firsst child.
So how can I do and also how to do too to get the attribute of state????????
查看 ID 为 2 的状态，文本description2不是description1。我认为解析器不会移动到第二个孩子，它总是在第一个孩子。那么我该怎么做以及怎么做才能获得状态的属性？？？？？？？？？？
采纳答案by nabeelmukhtar
You will have to do something like:
您将不得不执行以下操作：
for (int k = 0; k < States.getLength(); k++) {
String desc_state = xPath.evaluate("states/state[position()=" + (k + 1) + "]", workflow);
String id_employee = xPath.evaluate("states/state[position()=" + (k + 1) + "]/@IDemployee", workflow);
System.out.println(desc_state + ":" + id_employee);
}
