How to use @Until annotation using the Gson library in Java?

The @Until annotation can use with the setVersion() method of the GsonBuilder class. This annotation can apply to a field in java class and accepts float as an argument. This argument represents the version number in which the field has serialized. The @Until annotation can manage the versioning of JSON classes in web-services.

Syntax

@Documented
@Retention(value=RUNTIME)
@Target(value={FIELD,TYPE})
public @interface Until

Example

import com.google.gson.annotations.Until;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
public class GsonUntilAnnotationTest {
   public static void main(String[] args) {
      Employee emp = new Employee();
      emp.setEmployeeName("Adithya");
      emp.setEmployeeId(115);
      emp.setEmployeeTechnology("Python");
      emp.setEmploeeAddress("Pune");
      System.out.println("Using version 0.5");
      GsonBuilder gsonBuilder = new GsonBuilder();
      Gson gson = gsonBuilder.setPrettyPrinting().setVersion(0.5).create();
      String jsonString = gson.toJson(emp);
      System.out.println(jsonString);
      System.out.println("Using version 1.0");
      gsonBuilder = new GsonBuilder();
      gson = gsonBuilder.setPrettyPrinting().setVersion(1.0).create();
      jsonString = gson.toJson(emp);
      System.out.println(jsonString);
      System.out.println("Using version 1.1");
      gsonBuilder = new GsonBuilder();
      gson = gsonBuilder.setPrettyPrinting().setVersion(1.1).create();
      jsonString = gson.toJson(emp);
      System.out.println(jsonString);
   }
}
// Employee class
class Employee {
   private String empName;
   private int empId;
   @Until(1.1)
   private String empTech;
   @Until(1.1)
   private String empAddress;
   public String getEmployeeName() {
      return empName;
   }
   public void setEmployeeName(String empName) {
      this.empName = empName;
   }
   public int getEmployeeId() {
      return empId;
   }
   public void setEmployeeId(int empId) {
      this.empId = empId;
   }
   public String getEmployeeTechnology() {
      return empTech;
   }
  public void setEmployeeTechnology(String empTech) {
      this.empTech = empTech;
   }
   public String getEmploeeAddress() {
      return empAddress;
   }
   public void setEmploeeAddress(String empAddress) {
      this.empAddress = empAddress;
   }
}

Output

Using version 0.5
{
   "empName": "Adithya",
   "empId": 115,
   "empTech": "Python",
   "empAddress": "Pune"
}
Using version 1.0
{
   "empName": "Adithya",
   "empId": 115,
   "empTech": "Python",
   "empAddress": "Pune"
}
Using version 1.1
{
   "empName": "Adithya",
   "empId": 115
}