Apache Commons Digestter and Java -class library integration examples (Detailed Example of Integrating Apache Commons Digest With Java Class Libraries)
Apache Commons Digester is a popular Java library that provides a simple and flexible mechanism to map XML data to the Java object.This article will introduce how to integrate the Apache Commons Digerster and the Java class library and explain its usage through examples.
First, we need to introduce the Apache Commons Digester library in the project.You can download and import Digest's jar files on Apache's official website, or use Maven and other construction tools to manage dependence.
Let us use an example to illustrate how to use Digestter.Suppose we have a XML document, which contains some books of books, and we want to map it to the Java object.
XML example:
<library>
<book>
<Title> Java Programming Introduction </Title>
<emor> Zhang San </author>
<year>2021</year>
</book>
<book>
<Title> Python Program Design </Title>
<emor> Li Si </author>
<year>2020</year>
</book>
</library>
First of all, we need to create a Java class to represent book information:
public class Book {
private String title;
private String author;
private int year;
// getters and setters
@Override
public String toString() {
return "Book{" +
"title='" + title + '\'' +
", author='" + author + '\'' +
", year=" + year +
'}';
}
}
Next, we can write code to analyze XML and map it to the Java object.We will use the Digester object for these operations.The following is an example code for integrated Apache Commons Digest:
import org.apache.commons.digester3.Digester;
import java.io.File;
import java.io.IOException;
import java.util.List;
public class DigesterExample {
public static void main(String[] args) {
Digester digester = new Digester();
digester.setValidating(false);
digester.addObjectCreate("library/book", Book.class);
digester.addBeanPropertySetter("library/book/title", "title");
digester.addBeanPropertySetter("library/book/author", "author");
digester.addBeanPropertySetter("library/book/year", "year");
digester.addSetNext("library/book", "add");
try {
List<Book> books = (List<Book>) digester.parse(new File("books.xml"));
for (Book book : books) {
System.out.println(book);
}
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
In the above example, we first created the Digest instance and disabled the verification.Then, we use the `addObjectCreate () method to specify a new Book object when encountering the` Library/Book> `element.Next, we use the method of `addBeanpropertySetter ()` method to set the value of the xml element to the corresponding attribute of the Book object.Finally, we use the `addsetnext () method to add the processed Book object to the book list.
Finally, specify the path of the XML file in the `PARSE ()" method, and print the book information by traversing the boot object list returned from Digester.
By running the above code, you will be able to analyze XML and map it into the Java object.Apache Commons Digester provides many other methods and configuration options, which can be customized as needed.
This is a detailed example of integrating Apache Commons Digestter and Java class libraries.I hope this article can help you understand how to use the Digest Library to process XML data and map it to the Java object.
