Json Serialization and Deserialization using Java Jackson

Let us take a look at how to achieve serialization and deserialization using Java Jackson Library, we will first convert a Java Object to JSON and save it as a file, then read the file and convert it into Java Object.

Step 1: Serialization

Pojo: Album.java

import java.util.Arrays;

public class Album {

        private String artistName;
        private String albumName;
        private int releaseYear;
        private String[] songsList;

    public Album(String artistName, String albumName, int releaseYear, String[] songsList) {
        this.artistName = artistName;
        this.albumName = albumName;
        this.releaseYear = releaseYear;
        this.songsList = songsList;
    }

    public String getArtistName() {
        return artistName;
    }

    public void setArtistName(String artistName) {
        this.artistName = artistName;
    }

    public String getAlbumName() {
        return albumName;
    }

    public void setAlbumName(String albumName) {
        this.albumName = albumName;
    }

    public int getReleaseYear() {
        return releaseYear;
    }

    public void setReleaseYear(int releaseYear) {
        this.releaseYear = releaseYear;
    }

    public String[] getSongsList() {
        return songsList;
    }

    public void setSongsList(String[] songsList) {
        this.songsList = songsList;
    }

    @Override
    public String toString() {
        return "Album{" +
                "artistName='" + artistName + '\'' +
                ", albumName='" + albumName + '\'' +
                ", releaseYear=" + releaseYear +
                ", songsList=" + Arrays.toString(songsList) +
                '}';
    }
}

SerializationExampleJackson.java

import com.fasterxml.jackson.databind.ObjectMapper;

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

public class SerializationExampleJackson {

    public static void main(String[] args) {

        String[] songs = new String[9];
        songs[0] = "Wanna Be Startin Somethin";
        songs[1] = "Baby Be Mine";
        songs[2] = "The Girl Is Mine";
        songs[3] = "Thriller";
        songs[4] = "Beat it";
        songs[5] = "Billie Jean";
        songs[6] = "Human Nature";
        songs[7] = "P.Y.T. (Pretty Young Thing)";
        songs[8] = "The Lady in My Life";

        Album album = new Album("Michael Jackson","Thriller",1982,songs);

        try {
            String jsonFileName = "album.json";
            File jsonFile = new File(jsonFileName);
            ObjectMapper objectMapper = new ObjectMapper();
            objectMapper.writeValue(jsonFile, album);
            System.out.println("Java Object saved as Json File: album.json");
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Output: Java Object saved as Json File: album.json

Step 2: Deserialization

import com.fasterxml.jackson.databind.ObjectMapper;

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

public class DeserializationExampleJackson {

    public static void main(String[] args) {

        try {
            String jsonFileName = "album.json";
            File jsonFile = new File(jsonFileName);
            ObjectMapper objectMapper = new ObjectMapper();
            Album album = objectMapper.readValue(jsonFile, Album.class);

            System.out.println("Json read from album.json file..");
            System.out.println(album.getAlbumName());
            System.out.println(album.getArtistName());
            System.out.println(album.getReleaseYear());
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Output:

Json read from album.json file..
Thriller
Michael Jackson
1982

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