Use the Jackson DataFormat XML framework in the Java library for data binding
Use the Jackson DataFormat XML framework in the Java library for data binding
Overview:
In Java applications, processing XML data is a common demand.Jackson DataFormat XML is a popular Java class library that provides the function of converting XML data to Java objects and converting Java objects into XML data.This article will introduce how to use the Jackson DataFormat XML framework for data binding and provide some practical Java code examples.
Installation and dependence:
In order to start using the Jackson DataFormat XML, we first need to add it to the dependency item of the Maven or Gradle project.The following is an example of the Maven project:
<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-xml</artifactId>
<version>2.12.0</version>
</dependency>
Convert XML to Java object:
To convert the XML data to the Java object, we need to create a Java class corresponding to the XML structure.You can then use the XMLMAPPER class provided by the Jackson DataFormat XML to perform data binding.
Suppose we have a XML data that indicates books, as shown below:
<book>
<Title> Java Programming Introduction </Title>
<emor> Zhang San </author>
<year>2021</year>
</book>
Now, we create a Book class to map this XML structure:
public class Book {
private String title;
private String author;
private int year;
// getters and setters
}
Now you can use XMLMAPPER to convert XML data to Java object:
XmlMapper xmlMapper = new XmlMapper();
String xml = "<book><title>Java编程入门</title><author>张三</author><year>2021</year></book>";
Book book = xmlMapper.readValue(xml, Book.class);
This will analyze XML data and bind it into an instance of the Book class.
Convert the Java object to XML:
To convert the Java object to XML data, you can use the WriteValueasstring method of XMLMAPPER.
Book book = new Book();
book.settital ("Java Programming");
book.setauthor ("Zhang San");
book.setYear(2021);
String xml = xmlMapper.writeValueAsString(book);
System.out.println(xml);
The above code will print the following XML data:
<book>
<Title> Java Programming Introduction </Title>
<emor> Zhang San </author>
<year>2021</year>
</book>
Custom XML element name:
Sometimes XML element names with different attribute names from Java classes.You can use JAXB annotations to achieve custom XML element names.
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
@JacksonXmlRootElement(localName = "book")
public class Book {
@JacksonXmlProperty(localName = "book_title")
private String title;
@JacksonXmlProperty(localName = "book_author")
private String author;
@JacksonXmlProperty(localName = "book_year")
private int year;
// getters and setters
}
In this example,@jacksonxmlproperty is used to specify the name of the custom XML element.Now, when using XMLMAPPER to convert XML to Java objects and convert Java objects into XML, the name of the custom XML element will be used.
Summarize:
This article introduces how to use the Jackson DataFormat XML framework in Java applications for XML data binding.We understand how to convert XML data to Java objects, and also learn how to convert Java objects into XML data.In addition, we also understand how to use the JAXB annotation to define the name of the XML element.Through these knowledge, we can better process XML data in Java applications.
