This is how I populate the drop down list.I think it may help to you get some idea about it.
Controller
List<Operator> operators = operatorService.getAllOperaors()
model.addAttribute("operators", operators);
Model
@Entity
@Table(name = "operator")
public class Operator {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
@JsonIgnore
private Long id;
@NotBlank(message="operator Name cannot be empty")
@Column(name = "operator_name", nullable = false)
private String operatorName;
getters and setters ...
}
View
<div class="form-group blu-margin">
<select class="form-control" th:field="${operator.opeId}" id="dropOperator">
<option value="0">select operator</option>
<option th:each="operator : ${operators}" th:value="${operator.id}" th:text="${operator.operatorName}"></option>
</select>
</div>