How to read and write xml..

http://wenku.baidu.com/view/77a2181e10a6f524ccbf854b.html dom4j_API

http://wenku.baidu.com/view/7b1b3f79168884868762d607.html
http://www.cnblogs.com/shitianzeng/articles/2518323.html

1. Document object related

1. Read the XML file and get the document object.

SAXReader reader = new SAXReader();

Document document = reader.read(new File("input.xml"));

2. Parse the text in XML form and get the document object.

String text = "<members></members>";

Document document = DocumentHelper.parseText(text);

3. Actively create the document object.

Document document = DocumentHelper.createDocument();

Element root = document.addElement("members");//Create a root node

2. Node related

1. Get the root node of the document.

Element rootElm = document.getRootElement();

2. Get a single child node of a node.

Element memberElm=root.element("member");// "member" is the node name

3. Get the text of the node

String text=memberElm.getText();

You can also use:

String text=root.elementText("name"); This is the text to get the name byte point under the root node.

4. Get all the byte points named "member" under a node and traverse it.

List nodes = rootElm.elements("member");

for (Iterator it = nodes.iterator(); it.hasNext();) {

Element elm = (Element) it.next();

// do something

}

5. Traverse all child nodes under a node.

for(Iterator it=root.elementIterator();it.hasNext();){

Element element = (Element) it.next();

// do something

}

6. Add child nodes under a node.

Element ageElm = newMemberElm.addElement("age");

7. Set the node text.

ageElm.setText("29");

8. Delete a node.

parentElm.remove(childElm);// childElm is the node to be deleted, parentElm is its parent node

3. Attribute related.

1. Get an attribute under a node

Element root=document.getRootElement();

Attribute attribute=root.attribute("size");// 属性名name

2. Get the text of the attribute

String text=attribute.getText();

You can also use:

String text2=root.element("name").attributeValue("firstname"); This is to get the value of the attribute firstname of the name byte point under the root node.

3. Traverse all attributes of a node

Element root=document.getRootElement();

for(Iterator it=root.attributeIterator();it.hasNext();){

Attribute attribute = (Attribute) it.next();

String text=attribute.getText();

System.out.println(text);

}

4. Set the attributes and text of a node.

newMemberElm.addAttribute("name", "sitinspring");

5. Set the text of the attribute

Attribute attribute=root.attribute("name");

attribute.setText("sitinspring");

6. Delete an attribute

Attribute attribute=root.attribute("size");// 属性名name

root.remove(attribute);

4. Write the document to the XML file.

1. The document is all in English, no encoding is set, and it is written directly.

XMLWriter writer = new XMLWriter(new FileWriter("output.xml"));

writer.write(document);

writer.close();

2. The document contains Chinese, set the encoding format to write.

OutputFormat format = OutputFormat.createPrettyPrint();

format.setEncoding("GBK"); // Specify XML encoding

XMLWriter writer = new XMLWriter(new FileWriter("output.xml"),format);

writer.write(document);

writer.close();

Five. String and XML conversion

1. Convert the string to XML

String text = "<members> <member>sitinspring</member> </members>";

Document document = DocumentHelper.parseText(text);

2. Convert the XML of the document or node to a string.

SAXReader reader = new SAXReader();

Document document = reader.read(new File("input.xml"));

Element root=document.getRootElement();

String docXmlText=document.asXML();

String rootXmlText=root.asXML();

Element memberElm=root.element("member");

String memberXmlText=memberElm.asXML();

6. Use XPath to quickly find nodes.

Example of an XML document read

<?xml version="1.0" encoding="UTF-8"?>

<name>MemberManagement</name>

</projects>

<name>org.eclipse.jdt.core.javabuilder</name>

</arguments>

</buildCommand>

</buildSpec>

<nature>org.eclipse.jdt.core.javanature</nature>

</natures>

</projectDescription>

Quickly find node projects using XPath.

public static void main(String[] args){

SAXReader reader = new SAXReader();

try{

Document doc = reader.read(new File("sample.xml"));

List projects=doc.selectNodes("/projectDescription/projects/project");

Iterator it=projects.iterator();

while(it.hasNext()){

Element elm=(Element)it.next();

System.out.println(elm.getText());

}

catch(Exception ex){

ex.printStackTrace();

}

example:

package com.stz;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.DocumentHelper;

import org.dom4j.Element;

import org.dom4j.io.SAXReader;

import java.io.File;

import java.util.Iterator;

import java.util.List;

public class TestDate {

public static void main(String[]args){

String xml="<?xml version=\"1.0\" encoding=\"utf-8\"?>"+

"<students>"+

" <student id=\"1\">"+

" <name>stz</name>"+

" <age>23</age>"+

"</student>"+

"<student id=\"2\">"+

"<name>rhl</name>"+

"<age>23</age>"+

"</student>"+

"<student id=\"3\">"+

" <name>tom</name>"+

" <age>23</age>"+

"</student>"+

"</students>";

try {

Document document=DocumentHelper.parseText(xml);

Element root=document.getRootElement();

//System.out.println(ele.e);

//List nodes=root.elements("student");

//System.out.println(root.getName());

//root.elementIterator();

List nodes=document.selectNodes("/students/student");

for (Iterator it = nodes.iterator(); it.hasNext();) {

Element elm = (Element) it.next();

System.out.println("id:"+elm.attributeValue("id"));

System.out.println(elm.getName());

Element eles=elm.element("name");

System.out.println(eles.getText());

Element elea=elm.element("age");

System.out.println(elea.getText());

}

} catch (DocumentException e) {

// TODO Auto-generated catch block

e.printStackTrace ();

}

How to read and write xml..

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