JavaでJacksonを使用してシリアル化中にクラスを無視するにはどうすればよいですか？

import com.fasterxml.jackson.annotation.*;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import java.io.*;
public class JsonIgnoreTypeTest {
   public static void main(String args[]) throws IOException {
      Employee emp = new Employee();
      ObjectMapper mapper = new ObjectMapper();
      String jsonString = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(emp);
      System.out.println(jsonString);
   }
}
// Employee class
class Employee {
   @JsonIgnoreType
   public static class Address {
      public String firstLine = null;
      public String secondLine= null;
      public String thirdLine = null;
      @Override
      public String toString() {
         return "Address{" +
                "firstLine='" + firstLine+ '\'' +
                ", secondLine='" + secondLine+ '\'' +
                ", thirdLine='" + thirdLine + '\'' +
                '}';
      }
   } // end of Address class
   public long empId = 115;
   public String empName = "Raja Ramesh";
   public Address empAddress = new Address();
   @Override
   public String toString() {
      return "Employee{" +
             "empId=" + empId +
             ", empName='" + empName + '\'' +
             ", empAddress=" + empAddress +
             '}';
   }
}

出力

{
   "empId" : 115,
   "empName" : "Raja Ramesh"
}