Get specific fields

import java.lang.reflect.Field;
import java.util.Date;

public class Main {
  public static void main(String[] args) throws Exception {
    GetFields object = new GetFields();
    Class clazz = object.getClass();

    // Get all object accessible public fields.
    Field[] fields = clazz.getFields();
    System.out.println("Number of fields = " + fields.length);
    for (Field field : fields) {
      System.out.println("Field name = " + field.getName());
      System.out.println("Field type = " + field.getType().getName());
    }

    Field field = clazz.getField("id");
    System.out.println("Field name = " + field.getName());
    System.out.println("Field type = " + field.getType().getName());
  }
}

class GetFields {
  public Long id;

  protected String name;

  private Date birthDate;

  Double weight;

}