【Project screenshot】
[person.xml] Prepare an xml file
<?xml version="1.0" encoding="UTF-8"?>
<students>
<student id="88888" phone="15888888888" sex="男">
<name>张三</name>
<age>18</age>
<school>Tsinghua</school>
</student>
<student id="99999" phone="15999999999" sex="女">
<name>李四</name>
<age>28</age>
<school>北大</school>
</student>
<AAAA>
<aa1>aa111</aa1>
<aa2>aa222</aa2>
</AAAA>
<BBBB></BBBB>
</students>
[Read the content of the original Xml file, and then write the data to the disk]
package com.Higgin.dom4j;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
/**
* Read the content data of the original xml file, and then write the data to the XML file on the disk
*/
public class WriteDemo01 {
public static void main(String[] args) throws DocumentException, IOException {
//Read the existing Xml file person.xml
Document doc=new SAXReader().read(new File("./src/person.xml"));
//Specify the location of the file output
FileOutputStream out =new FileOutputStream("d:/student.xml");
//1. Create and write out object
XMLWriter writer=new XMLWriter(out);
//2. Write out the Document object
writer.write(doc);
//3. Close the stream
writer.close();
}
}
[Running result] The content is consistent with person.xml
[Save the xml content output to the corresponding disk address according to the set format]
package com.Higgin.dom4j;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
/**
* 1. Read the content data of the original xml file and save it to the Document object
* 2. Modify the output format (output format, encoding...)
* 3. Then write the document containing the data to the XML file on disk
*/
public class WriteDemo02 {
public static void main(String[] args) throws DocumentException, IOException {
//Read the existing Xml file person.xml
Document doc=new SAXReader().read(new File("./src/person.xml"));
//Specify the location of the file output
FileOutputStream out =new FileOutputStream("d:/student.xml");
/**
* Specify the format in which the text is written:
* Compact format: used when the project goes live
* Pretty format: used when developing and debugging
*/
//OutputFormat format=OutputFormat.createCompactFormat ( ); // Compact format : remove spaces and wrap
OutputFormat format =OutputFormat.createPrettyPrint ( ); // Pretty format : line break with spaces
/**
* Specifies that the encoding of the generated xml document affects:
* 1. The encoding when the xml document is saved
* 2. The encoding encoding declared by the xml document (the encoding during Xml parsing)
* Conclusion: Using this method to generate Xml documents can avoid the problem of Chinese garbled characters
*/
format.setEncoding("UTF-8");
//1. Create and write out object
XMLWriter writer=new XMLWriter(out,format);
//2. Write out the Document object
writer.write(doc);
//3. Close the stream
writer.close();
}
}
【operation result】
A student.xml file is also generated under the D drive
1. Compact format:
2. Pretty formatting
3. Note:
/**
* Specifying the encoding of the generated xml document affects:
* 1. The encoding of the xml document when it is saved
* 2. The encoding encoding declared by the xml document (the encoding during Xml parsing)
* Conclusion: Using this method to generate an Xml document can avoid Chinese garbled problem
*/
[ Add, delete, modify Xml files
/**
* 1. Create a Document object,
* Add: various tags, attributes, text
* Modify: attribute values, text
* Delete: tags, attributes
* 2. Modify the output format (output format, encoding...)
* 3. Then write the document containing the data to the XML file on disk
*/
】
[Add: document, tag, attribute]
/**
* Added: documents, tags, properties
*/
@Test
public void testAdd() throws DocumentException, IOException {
//1. Create a document
Document doc=DocumentHelper.createDocument();
//2. Add labels
Element rootElem=doc.addElement("root");
Element stuElem=rootElem.addElement("student");
stuElem.addElement("name");
//4. Add properties
stuElem.addAttribute("id", "88888");
stuElem.addAttribute("sex", "男");
//Specify the location of the file output
FileOutputStream out =new FileOutputStream("d:/student.xml");
// Specify the format in which the text is written:
OutputFormat format=OutputFormat.createPrettyPrint(); //Pretty format: line breaks with spaces
format.setEncoding("UTF-8");
//1. Create and write out object
XMLWriter writer=new XMLWriter(out,format);
//2. Write out the Document object
writer.write(doc);
//3. Close the stream
writer.close();
}
【operation result】
[Modification: attribute value, text]
/**
* Modify: attribute value, text
*/
@Test
public void testUpdate() throws DocumentException, IOException{
//Create a Document object and read the existing Xml file person.xml
Document doc=new SAXReader().read(new File("./src/person.xml"));
/**
* Modify the attribute value (Scheme 1)
* Method: Use the setValue() method of the Attribute class (attribute class)
* 1. Get the label object
* 2. Get the attribute object
* 3. Modify the attribute value
*/
/* //1.1 Get the label object
Element stuElem=doc.getRootElement().element("student");
//1.2 Get the id attribute object
Attribute idAttr=stuElem.attribute("id");
//1.3 Modify the attribute value
idAttr.setValue("000001");
*/
/**
* Modify attribute value (Scheme 2)
* Method: addAttribute("attr","value") method of Element tag class
*/
/* //1. Get the attribute value label
Element stuElem=doc.getRootElement().element("student");
//2. Modify the attribute value by adding the method of the attribute with the same name
stuElem.addAttribute ("id", " 000009 "); //key is the same, overwrite ; if there is no key, add
*/
/**
* Modify text
* method: setTest("new text value") method of Element tag class
* 1. Get the label object
* 2. Modify the text
*/
Element nameElem=doc.getRootElement().element("student").element("name");
nameElem.setText ("Wang Ermazi ");
//Specify the location of the file output
FileOutputStream out =new FileOutputStream("d:/student.xml");
// Specify the format in which the text is written:
OutputFormat format=OutputFormat.createPrettyPrint(); //Pretty format: line breaks with spaces
format.setEncoding("UTF-8");
//1. Create and write out object
XMLWriter writer=new XMLWriter(out,format);
//2. Write out the Document object
writer.write(doc);
//3. Close the stream
writer.close();
}
[Delete: tags, attributes]
/**
* delete: tags, attributes
*/
@Test
public void testDelete() throws DocumentException, IOException{
//Create a Document object and read the existing Xml file person.xml
Document doc=new SAXReader().read(new File("./src/person.xml"));
/**
* delete tag
* 1. Get the label object
* 2. Delete the tag object (you can delete the child tag through the parent class, or you can delete yourself)
*/
/* Element ageElement=doc.getRootElement().element("student").element("age");
ageElement.detach (); //Direct detch () delete
//ageElement.getParent().remove(ageElement ) ; //Get the parent tag first, then remove() to delete the child tag
*/
/**
* delete attribute
*/
//1. Get the label object
//equivalent to Element stuElem=doc.getRootElement().element("student");
Element stuElem = (Element) doc.getRootElement (). Elements (). Get (0);
//2. Get the attribute object
Attribute idAttr=stuElem.attribute("id");
//3. Delete property
idAttr.detach();
//Specify the location of the file output
FileOutputStream out =new FileOutputStream("d:/student.xml");
// Specify the format in which the text is written:
OutputFormat format=OutputFormat.createPrettyPrint(); //Pretty format: line breaks with spaces
format.setEncoding("UTF-8");
//1. Create and write out object
XMLWriter writer=new XMLWriter(out,format);
//2. Write out the Document object
writer.write(doc);
//3. Close the stream
writer.close();
}