Jackson Change Name of the Field

When we serialize a Java Object, we need to change the name of a specific field for mapping it with another JSON property. It is one of the most used and important concepts of Jackson to learn and understand.

In order to change the field name, we use the @JsonProperty annotation. In the annotation constructor, we pass the name of the property.

Let's take an example to understand how we can use @JsonProperty annotation to change the name of the field for serialization.

ChangeNameOfFieldExample.java

//import required classes and package if any  

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

//create class ChangeNameOfFieldExample to understand how we can change the name of the field while serializing
public class ChangeNameOfFieldExample {  

	//main() methods start  
	public static void main(String args[]) {  

		// create an instance of ObjectMapper class  
		ObjectMapper mapper = new ObjectMapper();  

		String json = "{\"name\":\"ABES\",\"university\":\"AKTU\", \"address\":\"NH-24 Highway GZB UP\", \"rank\":\"1\"}";  
	       
		// de-serializing Json into Java object  
		College colg;
		try {
			colg = mapper.readerFor(College.class).readValue(json);
			
			// print id, name and course of student  
		    System.out.println(colg.getCollegeName());  
		    System.out.println(colg.getUniversityName());  
		    System.out.println(colg.getAddress());
		    System.out.println(colg.getRank());
		    
		} catch (JsonMappingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (JsonProcessingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}  
} 
//create class College
class College {    

	//Creating properties of College class    
	private String name;      
	private String university;   
	private String address; 
	private String rank;   
	
	// default constructor 
	College(){
		
	}
	
	// constructor  
	College(String name, String university, String address, String rank){  
		this.name = name;  
		this.university = university;  
		this.address = address;  
		this.rank = rank;  
	}  
	@JsonProperty("name")  
	public String getCollegeName() {  
		return name;  
	}
	public void setCollegeName(String name) {  
		this.name = name;  
	}
	@JsonProperty("university")  
	public String getUniversityName() {  
		return university;  
	}
	public void setUniversityName(String university) {  
		this.university = university;
	}
	public String getAddress() {  
		return address;  
	}
	public void setAddress(String address) {  
		this.address = address;  
	}
	public String getRank() {  
		return rank;  
	}
	public void setRank(String rank) {  
		this.rank = rank;  
	}
}

Output: