In -depth research on the technical principles of Jackson DataFormat XML framework in the Java class library
Jackson DataFormat XML is a Java class library for processing XML format data.It is based on the Jackson framework and provides a way to convert XML data with Java objects.This article will study the principles of Jackson DataFormat XML and provide relevant Java code examples.
Jackson is a popular JAVA serialization and desertified library, which was originally designed to process JSON data.However, as XML is still widely used in many systems, Jackson also provides expansion modules for processing XML data.Among them, Jackson DataFormat XML is one of the optional modules.
Jackson DataFormat XML realizes the conversion between XML data and Java objects through two classes: `xmlmapper` and` jacksonxmlmodule`.
`Xmlmapper` is one of the most important categories in the Jackson XML package.It is an extension of the ObjectMapper (an object of the JSON data) in the Jackson framework.`Xmlmapper` has the ability to process XML data.Using `xmlmapper`, we can convert XML data to Java objects, or convert the Java object to XML data.
The following is a simple example that shows how to use `xmlmapper` to convert XML data to Java object:
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
public class XmlToObjectExample {
public static void main(String[] args) throws Exception {
String xmlData = "<person><name>John Doe</name><age>30</age></person>";
XmlMapper xmlMapper = new XmlMapper();
Person person = xmlMapper.readValue(xmlData, Person.class);
System.out.println("Name: " + person.getName());
System.out.println("Age: " + person.getAge());
}
}
class Person {
private String name;
private int age;
// getters and setters
}
In the above code, we process XML data by creating a `xmlmapper` object.Then, we use the `Readvalue` method to convert the XML string to the` Person` object.Finally, we can use the Getter method of the `Person` object to obtain the conversion data.
In addition to converting XML data to Java objects, Jackson DataFormat XML can also perform reverse operations and convert Java objects to XML data.The following is an example that shows how to use `xmlmapper` to convert the Java object to XML data:
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
public class ObjectToXmlExample {
public static void main(String[] args) throws Exception {
Person person = new Person();
person.setName("John Doe");
person.setAge(30);
XmlMapper xmlMapper = new XmlMapper();
String xmlData = xmlMapper.writeValueAsString(person);
System.out.println(xmlData);
}
}
class Person {
private String name;
private int age;
\t// getters and setters
}
In the above code, we first create an `Person` object and set its attributes.Then, we use the `xmlmapper` '` writevalueasstring` method to convert the `Person` object to XML string.
In summary, Jackson DataFormat XML is an extension module of the Jackson library for processing XML data.It provides the function of converting XML data with Java objects through the `xmlmapper` class.We can use the `Readvalue` method of` xmlmapper` to convert XML data to Java objects, or use the `writevalueasstring` method to convert the Java object to XML data.
