Spring Boot DTO在Controller上为空

Question

是Spring引导的新手。我正在尝试创建一个将在manager下添加车辆的端点。我下面有两个实体Vehicle和Manager，以及相应的DTO。 DTO经理引用了VehicleDTO

VehicleDTO

<form action = "edit.php" method="POST" enctype="multipart/form-data">
	<div class="form-group">

		<label for="title">Title of the Article</label>
			<input type="text" class="form-control" id="title" name="title" value="<?php echo $title; ?>">
			<br \>
			<label for="bodyContent">Content</label>
			<textarea class="form-control" rows="5" id="content" name="content"><?php echo $content; ?></textarea>
			<br>
			<div class="row">
				<div class="col-md-4">
					<label for="exampleFormControlFile1">Upload Image Only</label>
    				<input type="file" name="image" class="form-control-file" id="image">
    				<div class="col-md-12">
    				<?php
    					if(empty($images_)){
    						//nnothing to display
    					}else{
    						echo "<img src='uploaded_files/uploaded_files_articles_images/$images_' class='img-responsive img-rounded'>";		
    					}
    				?>
    				</div>		
				</div>
				<div class="col-md-4">
					<label for="exampleFormControlFile1">Upload File</label>
    				<input type="file" name="files" class="form-control-file" id="files">
    				<div class="col-md-12">
    					<?php
    						if(empty($files_)){
    							//nothing to display
    						}else{
    							echo "<a href='uploaded_files/uploaded_files_articles/$files_' download>".$files_."</p>";
    						}
    					?>
    				</div>
				</div>
				<div class="col-md-4">
					<input type="hidden" name="id" value=<?php echo $_GET['id']; ?>>	
				</div>	
			</div>
		<br>
		
		<button type="submit" name="btn-update" class="btn btn-primary">Update</button>	
	</div>
</form>

我的ManagerDTO在下面。这参考了Vehcile DTO

import javax.validation.constraints.Max;
import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonPOJOBuilder;
import com.EngineType;
import com.Manufacturer;

@JsonDeserialize(builder = VehicleDTO.VehicleDTOBuilder.class)
@JsonInclude(JsonInclude.Include.NON_NULL)
public class VehicleDTO {

    private Long vehicleid;

    @NotNull(message = "vehcilenumber can not be null!")
    @Size(min = 2, max = 14)
    private String vehcilenumber;

    @NotNull(message = "Engine Type can not be null!")
    private EngineType enginetype;

    @Min(1)
    @Max(5)
    private Integer rating;

    private Manufacturer manufacturer;

    private VehicleDTO(Long id, String vehcilenumber, EngineType enginetype,Integer rating,Manufacturer manufacturer){
        this.vehcilenumber=vehcilenumber;
        this.enginetype=enginetype;
        this.rating=rating;
        this.vehicleid=id;
        this.manufacturer=manufacturer;
    }

    public static VehicleDTOBuilder newBuilder()
    {
        return new VehicleDTOBuilder();
    }

    public Long getvehicleid() {
        return vehicleid;
    }


    public String getvehcilenumber() {
        return vehcilenumber;
    }

    public EngineType getEnginetype() {
        return enginetype;
    }



    public Integer getRating() {
        return rating;
    }


    public Manufacturer getManufacture() {
        return manufacturer;
    }



    @JsonPOJOBuilder(buildMethodName = "createVehicleDTO", withPrefix = "set")
    public static class VehicleDTOBuilder{

        private Long vehicleid;
        private String vehcilenumber;
        private EngineType enginetype;
        private Integer rating;
        private Manufacturer manufacturer;

        public VehicleDTOBuilder setvehicleid(Long id) {
            this.vehicleid = id;
            return this;
        }
        public VehicleDTOBuilder setvehcilenumber(String vehcilenumber) {
            this.vehcilenumber = vehcilenumber;
            return this;
        }

        public VehicleDTOBuilder setEnginetype(EngineType enginetype) {
            this.enginetype = enginetype;
            return this;
        }
        public VehicleDTOBuilder setRating(Integer rating) {
            this.rating = rating;
            return this;
        }


        public VehicleDTOBuilder setManufacturer(Manufacturer manufacturer) {
            this.manufacturer = manufacturer;
            return this;
        }

        public VehicleDTO createVehicleDTO()
        {
            return new VehicleDTO(vehicleid, vehcilenumber, enginetype,rating,manufacturer);
        }

    }

}

我的控制器在下面

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.VehicleDO;
import javax.validation.constraints.NotNull;

@JsonInclude(JsonInclude.Include.NON_NULL)
public class ManagerDTO {
    @JsonIgnore
    private Long id;

    @NotNull(message = "Username can not be null!")
    private String username;

    @NotNull(message = "Password can not be null!")
    private String password;

    private VehicleDO vehicle;

    private ManagerDTO() {
    }

    private ManagerDTO(Long id, String username, String password) {
        this.id = id;
        this.username = username;
        this.password = password;
    }

    private ManagerDTO(Long id, String username, String password,VehicleDO vehicle) {
        this.id = id;
        this.username = username;
        this.password = password;
        this.vehicle = vehicle;
    }

    public static ManagerDTOBuilder newBuilder() {
        return new ManagerDTOBuilder();
    }

    @JsonProperty
    public Long getId() {
        return id;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }

    public VehicleDO getvehicle() {
        return vehicle;
    }

    public static class ManagerDTOBuilder {
        private Long id;
        private String username;
        private String password;
        private VehicleDO vehicle;

        public ManagerDTOBuilder setId(Long id) {
            this.id = id;
            return this;
        }

        public ManagerDTOBuilder setvehicle(VehicleDO vehicle) {
            this.vehicle = vehicle;
            return this;
        }

        public ManagerDTOBuilder setUsername(String username) {
            this.username = username;
            return this;
        }

        public ManagerDTOBuilder setPassword(String password) {
            this.password = password;
            return this;
        }


        public ManagerDTO createManagerDTO() {
            return new ManagerDTO(id, username, password,vehicle);
        }

    }
}

因此，当我的控制器被调用时，我可以看到用户名和密码已被填充，而未填充车辆。不知道这里缺少什么，以及杰克逊未填充我的Java对象的原因。