Convert Java Object to Json String using Jackson API

Difficulty Level : Medium
Last Updated : 16 Oct, 2020

JSON Stand for JavaScript Object Notation. It’s a standard text-based format which shows structured data based on JavaScript object syntax. It is commonly used for transmitting data in web applications. JSON is highly recommended to transmit data between a server and web application.
To convert a Java object into JSON, the following methods can be used:

GSON
JACKSON API

In this article, Java object is converted into the JSON using Jackson API:
The steps to do this are as follows:

Add jar files of Jackson (in case of Maven project add Jackson dependencies in pom.xml file)

html

<dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.5.3</version>
</dependency>

Below is the screenshot showing this step:

Create a POJO (Plain Old Java Object) to be converted into JSON
Java Class

Java

package com.Geeks;
 
public class Organisation {
    private String organisation_name;
    private String description;
    private int Employees;
 
    // Calling getters and setters
    public String getOrganisation_name()
    {
        return organisation_name;
    }
 
    public void setOrganisation_name(String organisation_name)
    {
        this.organisation_name = organisation_name;
    }
 
    public String getDescription()
    {
        return description;
    }
 
    public void setDescription(String description)
    {
        this.description = description;
    }
 
    public int getEmployees()
    {
        return Employees;
    }
 
    public void setEmployees(int employees)
    {
        Employees = employees;
    }
 
    // Creating toString
    @Override
    public String toString()
    {
        return "Organisation [organisation_name="
            + organisation_name
            + ", description="
            + description
            + ", Employees="
            + Employees + "]";
    }
}

Below is the screenshot showing this step:

Create a Java class for converting the Organisation object into JSON. Convert the object into JSON using ObjectMapper class of Jackson API.

Java

package com.Geeks;
 
import java.io.IOException;
import org.codehaus.jackson.map.ObjectMapper;
import com.Geeks.Organisation;
 
public class ObjectToJson {
    public static void main(String[] a)
    {
 
        // Creating object of Organisation
        Organisation org = new Organisation();
 
        // Insert the data into the object
        org = getObjectData(org);
 
        // Creating Object of ObjectMapper define in Jakson Api
        ObjectMapper Obj = new ObjectMapper();
 
        try {
 
            // get Oraganisation object as a json string
            String jsonStr = Obj.writeValueAsString(org);
 
            // Displaying JSON String
            System.out.println(jsonStr);
        }
 
        catch (IOException e) {
            e.printStackTrace();
        }
    }
 
    // Get the data to be inserted into the object
    public static Organisation getObjectData(Organisation org)
    {
 
        // Insert the data
        org.setName("GeeksforGeeks");
        org.setDescription("A computer Science portal for Geeks");
        org.setEmployees(2000);
 
        // Return the object
        return org;
    }

Execute the process.
The output in the JSON will be as below:

Output
{
  "organisation_name" : "GeeksforGeeks",
  "description" : "A computer Science portal for Geeks",
  "Employee" : "2000"
}

Below is the screenshot showing this output:

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