java xml 删除项目 [英] java xml remove item
本文介绍了java xml 删除项目的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有一个非常简单的 xml 文件,我想创建一个简单的函数来从中删除项目.这是我的 xml 文件:
I have a very simple xml file that I would like to create a simple function to remove an item from it. Here is my xml file:
<?xml version="1.0"?>
<book>
<person>
<name>Person 1</name>
</person>
<person>
<name>Person 2</name>
</person>
<person>
<name>Person 3</name>
</person>
<person>
<name>Person 4</name>
</person>
</book>
我只想调用一种方法来从文件中删除一个名称.我对 XML 不是很熟悉,但确实设法创建了读取器和写入器,但现在我无法创建从文件中删除项目的方法.
I simply want to call a method to delete one name from the file. I'm not very familiar with XML but did manage to create a reader and writer but now I'm having trouble creating a method to delete an item from my file.
当我说删除一个项目时,我的意思是:
When I say delete an item I mean:
deleteItem("Person 3");
然后 XML 文件将更改为:
And then the XML file will change to:
<?xml version="1.0"?>
<book>
<person>
<name>Person 1</name>
</person>
<person>
<name>Person 2</name>
</person>
<person>
<name>Person 4</name>
</person>
</book>
我做错了什么:
public static void removeName(String personName) throws ParserConfigurationException, IOException, SAXException{
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse (new File("test.xml"));
NodeList nodes = doc.getElementsByTagName("person");
for (int i = 0; i < nodes.getLength(); i++) {
Element person = (Element)nodes.item(i);
Element name = (Element)person.getElementsByTagName("name").item(0);
String pName = name.getTextContent();
if(pName.equals(personName)){
person.getParentNode().removeChild(person);
}
}
}
推荐答案
使用 DOM:
public static void main(String[] args) throws Exception {
final String xml = "<book> " +
"<person> " +
"<name>Person 1</name> " +
"</person> " +
"<person> " +
"<name>Person 2</name> " +
"</person> " +
"<person> " +
"<name>Person 3</name> " +
"</person> " +
"<person> " +
"<name>Person 4</name> " +
"</person> " +
"</book>";
DocumentBuilderFactory dbf =
DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(xml));
Document doc = db.parse(is);
deletePerson(doc, "Person 3");
printXML(doc);
}
public static void deletePerson(Document doc, String personName) {
// <person>
NodeList nodes = doc.getElementsByTagName("person");
for (int i = 0; i < nodes.getLength(); i++) {
Element person = (Element)nodes.item(i);
// <name>
Element name = (Element)person.getElementsByTagName("name").item(0);
String pName = name.getTextContent();
if (pName.equals(personName)) {
person.getParentNode().removeChild(person);
}
}
}
public static void printXML(Document doc)
throws TransformerException {
Transformer transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StreamResult result = new StreamResult(new StringWriter());
DOMSource source = new DOMSource(doc);
transformer.transform(source, result);
String xmlString = result.getWriter().toString();
System.out.println(xmlString);
}
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