Dom4j
What is Dom4j?
Dom4j is a Java library used to process XML documents. It provides an efficient and flexible way to parse, generate, manipulate and serialize XML data. Dom4j combines the advantages of Dom, SAX, and JDOM to provide an easy-to-use API, allowing developers to easily perform XML operations.
The role of Dom4j
- parse XML: DOM4J can parse XML documents into a tree structure in memory, which facilitates subsequent operations and queries.
- Generate XML:DOM4J provides a method to create XML documents, which can easily generate new XML files.
- Operation XML:DOM4J allows modification of existing XML documents, including adding, deleting, and modifying nodes.
- Serialize XML:DOM4J can output XML tree structures in memory as XML files or strings.
Dom4j usage scenarios
- Data exchange: XML is a common data format when exchanging data between different systems. DOM4J can easily parse and generate XML data to ensure the correctness and consistency of the data.
- Configuration file management: Many applications use XML files as configuration files. DOM4J can help developers read and modify these configuration files without manually parsing and generating XML.
- Logging: In some application scenarios, log information needs to be stored in XML format. DOM4J can easily generate and parse these log files.
- Data persistence: In some cases, data needs to be persisted in XML format into a file or database. DOM4J provides a convenient way to achieve this.
- Web Services: In web services, requests and responses are often transmitted in XML format. DOM4J can help developers process this XML data and improve development efficiency.
How to use Dom4j to parse and operate an xml file with a three-level directory structure.
Add Dom4j dependencies
<dependencies>
<dependency>
<groupId>dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>2.1.3</version>
</dependency>
</dependencies>Create an xml file -- the following file is used as an example ()
<?xml version="1.0" encoding="UTF-8"?>
<environment>
<!-- Collection module -->
<gather class="">
<!-- The path to the original data file to be parsed -->
<srcPath>radwtmp-all</srcPath>
<!-- Collection moduleThe name of the backup file used -->
<backupFilePath></backupFilePath>
</gather>
<!-- Network module（Client） -->
<client class="">
<!-- Server-sideIP -->
<clientHost>127.0.0.1</clientHost>
<!-- Server-side端口号 -->
<clientPort>33333</clientPort>
<!-- Network module（Client）The name of the backup file used -->
<backupFilePath></backupFilePath>
</client>
<!-- Log module -->
<logger class="">
<!-- Log4jFramework configuration file path -->
<configPath></configPath>
</logger>
<!-- Backup module -->
<backup class="">
<!-- The path to save all backup files -->
<backupDir>backup</backupDir>
</backup>
</environment>Use Dom4j to parse xml files
import org.;
import org.;
import org.;
import ;
public class Dom4jExample {
public static void main(String[] args) {
try {
// Create a SAXReader parser object SAXReader reader = new SAXReader();
// Load XML file // The parser object uses this input stream to load the xml file and obtain the document content Document document = (new File(""));
// Get the root element <environment> Element rootElement = ();
// Get all direct child elements through the root element (representing the module's element) List<Element> elements = ();
// traverse the collection and process each module element for (Element element : elements) {
// Get the name of the element and use it as the key of each module, such as: server dbStore String name = ();
// Read the class attribute from the module element (the full class name of each module) String className = ("class");
("Name: " + name);
("Class: " + className);
// Get all the child elements in each module, each child element is a configuration information for (Element childElement : ()) {
// Get the name of the child element as the name of the configuration item String configName = ();
// Get the text value in the child element label body as the value of the configuration item String configText = ();
("Child Name: " + childName);
("Child Text: " + childText);
}
();
}
} catch (Exception e) {
();
}
}
}Code explanation:
- create
SAXReaderObject: Used to parse XML files. - Loading XML files: Use
SAXReaderRead the file and returnDocumentObject. - Get the root element:
DocumentGet the root element in the object. - Traverses the child elements of the root element: Iterates through all child elements under the root element and gets their names and attributes.
- Traverses child elements of child elements: Iterates over all child elements under each child element and gets their name and text content.
Generate xml file
import org.;
import org.;
import org.;
import org.;
import org.;
import ;
import ;
public class Dom4jGenerateExample {
public static void main(String[] args) {
try {
// Create a new Document object Document document = ();
// Create root element Element rootElement = ("environment");
// Add child elements Element gather = ("gather")
.addAttribute("class", "");
("srcPath").setText("radwtmp-all");
("backupFilePath").setText("");
Element client = ("client")
.addAttribute("class", "");
("clientHost").setText("127.0.0.1");
("clientPort").setText("33333");
("backupFilePath").setText("");
Element logger = ("logger")
.addAttribute("class", "");
("configPath").setText("");
Element backup = ("backup")
.addAttribute("class", "");
("backupDir").setText("backup");
// Set the output format OutputFormat format = ();
("UTF-8");
// Create XMLWriter object XMLWriter writer = new XMLWriter(new FileWriter("generated_environment.xml"), format);
// Write to XML file (document);
();
("XML file generation successfully!");
} catch (IOException e) {
();
}
}
}This is the end of this article about the detailed analysis of Dom4j configuration and use of Dom4j in Java. For more related Java Dom4j configuration content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!