在retrofit2中传递自定义对象

我正试图通过retrofit2传递一个自定义对象，我的问题是服务器是否会自动将我的自定义对象写入json，或者我是否必须为此编写一个php文件。与此同时，我成功地发布到服务器上，但无法写入json。

我的目标是将自定义对象写入服务器，并将自定义对象的内容写入json文件。

这是我的改装Api

public interface ApsaraCatalogAPI {
    @GET("/apsaratrendz/data/apsara_json_document_v2.json")
    Call<List<ApsaraCatalogModel>> getFeed();
    @POST("/apsaratrendz/data/apsara_json_orders_document.json")
    Call<Void> setOrder(@Body OrderModel orderModel);
}

这是我调用的api函数

@Override
    public void onClick(View v) {
        int total = 0;
        if(v.getId()==R.id.fabButtonCart && cartlist.size()!=0)
        {
            // get details from shared preferences
            OrderModel orderModel = new OrderModel();
            orderModel.setDate(getDate());
            orderModel.setName("ssdfs");
            orderModel.setEmail("sdf@gmail.com");
            orderModel.setNoofitems(String.valueOf(cartlist.size()));
            orderModel.setOrderno("32335");
            orderModel.setPhone("9896566444");
            for(int i=0; i<cartlist.size();i++){
                Productdetail pd = new Productdetail();
                pd.getSellingprice(String.valueOf(cartlist.get(i).getSellingPrice()));
                pd.getPid(cartlist.get(i).getEANCode());
                total += cartlist.get(i).getSellingPrice();
                orderModel.getProductdetails().add(pd);
            }
            //
            // now go for insertion using retrofit
            requestData(orderModel);
            Toast.makeText(getApplicationContext(), "Total Price : Rs."+total+"/-", Toast.LENGTH_LONG).show();
        }else{
            Toast.makeText(getApplicationContext(), "Cart is Empty", Toast.LENGTH_LONG).show();
        }
    }

这是我对改进api的服务请求，我正在传递新创建的POJO OrderModel类。

private void requestData(OrderModel orderModel) {
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(ENDPOINT)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        ApsaraCatalogAPI service = retrofit.create(ApsaraCatalogAPI.class);
        Call<Void> call = service.setOrder(orderModel);
        call.enqueue(new Callback<Void>() {
        @Override
        public void onResponse(Call<Void> call, Response<Void> response) {
            if(response.isSuccessful()){
                Log.d("InApi","Yipppie");
            }
        }
        @Override
        public void onFailure(Call<Void> call, Throwable t) {
            Log.d("InApi","Kaboom");
        }
    });
    }

我的POJO课程如下：

import java.util.Map;
        import java.util.ArrayList;
        import java.util.HashMap;
        import java.util.List;
public class OrderModel {
    private String name;
    private String email;
    private String phone;
    private String orderno;
    private String date;
    private String noofitems;
    private List<Productdetail> productdetails = new ArrayList<Productdetail>();
    private Map<String, Object> additionalProperties = new HashMap<String, Object>();
    /**
     *
     * @return
     * The name
     */
    public String getName() {
        return name;
    }
    /**
     *
     * @param name
     * The name
     */
    public void setName(String name) {
        this.name = name;
    }
    /**
     *
     * @return
     * The email
     */
    public String getEmail() {
        return email;
    }
    /**
     *
     * @param email
     * The email
     */
    public void setEmail(String email) {
        this.email = email;
    }
    /**
     *
     * @return
     * The phone
     */
    public String getPhone() {
        return phone;
    }
    /**
     *
     * @param phone
     * The phone
     */
    public void setPhone(String phone) {
        this.phone = phone;
    }
    /**
     *
     * @return
     * The orderno
     */
    public String getOrderno() {
        return orderno;
    }
    /**
     *
     * @param orderno
     * The orderno
     */
    public void setOrderno(String orderno) {
        this.orderno = orderno;
    }
    /**
     *
     * @return
     * The date
     */
    public String getDate() {
        return date;
    }
    /**
     *
     * @param date
     * The date
     */
    public void setDate(String date) {
        this.date = date;
    }
    /**
     *
     * @return
     * The noofitems
     */
    public String getNoofitems() {
        return noofitems;
    }
    /**
     *
     * @param noofitems
     * The noofitems
     */
    public void setNoofitems(String noofitems) {
        this.noofitems = noofitems;
    }
    /**
     *
     * @return
     * The productdetails
     */
    public List<Productdetail> getProductdetails() {
        return productdetails;
    }
    /**
     *
     * @param productdetails
     * The productdetails
     */
    public void setProductdetails(List<Productdetail> productdetails) {
        this.productdetails = productdetails;
    }
    public Map<String, Object> getAdditionalProperties() {
        return this.additionalProperties;
    }
    public void setAdditionalProperty(String name, Object value) {
        this.additionalProperties.put(name, value);
    }
}

productdetails类：

import java.util.HashMap;
import java.util.Map;
public class Productdetail {
    private String pid;
    private String sellingprice;
    private Map<String, Object> additionalProperties = new HashMap<String, Object>();
    /**
     *
     * @return
     * The pid
     * @param s
     */
    public String getPid(String s) {
        return pid;
    }
    /**
     *
     * @param pid
     * The pid
     */
    public void setPid(String pid) {
        this.pid = pid;
    }
    /**
     *
     * @return
     * The sellingprice
     * @param s
     */
    public String getSellingprice(String s) {
        return sellingprice;
    }
    /**
     *
     * @param sellingprice
     * The sellingprice
     */
    public void setSellingprice(String sellingprice) {
        this.sellingprice = sellingprice;
    }
    public Map<String, Object> getAdditionalProperties() {
        return this.additionalProperties;
    }
    public void setAdditionalProperty(String name, Object value) {
        this.additionalProperties.put(name, value);
    }
}