How to read and write Java object to JSON file?

The following example demonstrate how to serialize and deserialize Java object to JSON file. The Jackson’s ObjectMapper class provides writeValue(File, Object) and readValue(File, Class<T>) methods which allow us to write an object into JSON file and read JSON file into an object respectively.

package org.kodejava.jackson;

import com.fasterxml.jackson.databind.ObjectMapper;
import org.kodejava.jackson.support.Artist;

import java.io.File;
import java.io.IOException;

public class ObjectToJsonFile {
    public static void main(String[] args) {
        Artist artist = new Artist();
        artist.setId(1L);
        artist.setName("The Beatles");

        ObjectMapper mapper = new ObjectMapper();

        File file = new File("artist.json");
        try {
            // Serialize Java object info JSON file.
            mapper.writeValue(file, artist);
        } catch (IOException e) {
            e.printStackTrace();
        }

        try {
            // Deserialize JSON file into Java object.
            Artist newArtist = mapper.readValue(file, Artist.class);
            System.out.println("newArtist.getId() = " + newArtist.getId());
            System.out.println("newArtist.getName() = " + newArtist.getName());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

The result of the code snippet are:

newArtist.getId() = 1
newArtist.getName() = The Beatles

Maven Dependencies

<dependencies>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.17.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.17.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.17.1</version>
    </dependency>
</dependencies>

Author
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Wayan

Founder at Kode Java

A programmer, runner and recreational diver, lives on the island of Bali, Indonesia. Programming in Java, Spring Framework, Hibernate / JPA, MySQL. To support me working on this project, buy me a cup of coffee, every little bit helps. Thank you.

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