Writing a custom JSON IO adapter for the Java library
Writing a custom JSON IO adapter for the Java library
When using Java for development, the Java object is often transformed into a JSON string or a JSON string derivative into a Java object.Although most Java libraries provide built -in JSON serialization and dependentization functions, for specific class libraries, it may not necessarily meet all needs.In order to provide a stronger and flexible JSON IO function, you can use a custom JSON IO adapter.
This tutorial will introduce how to write a custom JSON IO adapter for the Java library.We will explain through an example that uses a Java class called "Book" in the example.At the same time, we will also provide some Java code related to this example.
1. Add related dependencies
In order to support JSON serialization and derivativeization, we need to add a JSON library as dependencies.In this example, we use the Jackson library as the JSON library.In the Maven project, you can add the following dependencies to the pom.xml file:
<dependencies>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.12.4</version>
</dependency>
</dependencies>
2. Create a book class
First, we need to define a Java class to represent books.This class should include attributes and methods related to books.In this example, we assume that the Book class has the following attributes: ID, title and Author.The following is an example code:
public class Book {
private int id;
private String title;
private String author;
// Construct function, Getter, and Setter method omitted
@Override
public String toString() {
return "Book{" +
"id=" + id +
", title='" + title + '\'' +
", author='" + author + '\'' +
'}';
}
}
3. Create a JSON IO adapter
Now, we will create a JSON IO adapter to realize the conversion between the Book class and JSON through it.To use the Jackson library, we can directly use Jackson's ObjectMapper class.The following is an example of the JSON IO adapter:
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class BookJsonAdapter {
private ObjectMapper objectMapper;
public BookJsonAdapter() {
objectMapper = new ObjectMapper();
}
public String serialize(Book book) throws JsonProcessingException {
return objectMapper.writeValueAsString(book);
}
public Book deserialize(String json) throws JsonProcessingException {
return objectMapper.readValue(json, Book.class);
}
}
In the above adapter, we use the Writevalueasstring () method of the ObjectMapper class to sequence the Book objects into a JSON string, and use the Readvalue () method to turn the JSON string derivative to the BOOK object.
4. Test the adapter
In order to verify whether our adapter works normally, we can write some test code.The following is a simple test example:
public class Main {
public static void main(String[] args) throws JsonProcessingException {
BOOK BOOK = New Book (1, "Java Programming", "Zhang San");
BookJsonAdapter adapter = new BookJsonAdapter();
String json = adapter.serialize(book);
System.out.println("Serialized JSON: " + json);
Book deserializedBook = adapter.deserialize(json);
System.out.println("Deserialized Book: " + deserializedBook);
}
}
Run the above code will display the JSON representation form of the Book object and the information of the Book object after -order.
Summarize
Writing a custom JSON IO adapter can provide the Java class library with more powerful and flexible JSON serialization and back -sequencing functions.This tutorial introduces how to achieve a custom JSON IO adapter through an example.By the adapter, we can sequence the Java object into a JSON string, and the derivative of the JSON string to the Java object.I hope this tutorial can help you better understand how to write custom JSON IO adapter for the Java class library.
