GSON＆Volley =>预计BEGIN_ARRAY，但是在BEGIN_OBJECT第1行第2列路径$

Question

这个错误让我疯狂我尝试使用不同种类的排球请求，如JsonArrayRequest和JsonObjectRequest，但没有运气！

com.google.gson.JsonSyntaxException：java.lang.IllegalStateException：预期BEGIN_ARRAY但BEGIN_OBJECT位于第1行第2列路径$

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这里的JSON响应链接=>http://www.mocky.io/v2/58df83a80f00005922eaf4e1

---

这里是我的模型类

public class Order { 


@SerializedName("status") 
@Expose 
private String status; //status 

@SerializedName("total") 
@Expose 
private float price; //total 


@SerializedName("created_at") 
@Expose 
private Date time; 

@SerializedName("line_items") 
@Expose 
public List<ItemsNum> lineItems = new ArrayList<ItemsNum>(); 

@SerializedName("sub_orders") 
@Expose 
public List<OrdersNum> subOrders = new ArrayList<OrdersNum>(); 

@SerializedName("shipping_address") 
@Expose 
public CusAddress cusAdress; 

@SerializedName("customer") 
@Expose 
public Customer customer; 


public Order(Customer customer, String status, float price, String cusPicURL, String firstName, String lastName, Date time, List<ItemsNum> lineItems, List<OrdersNum> subOrders, CusAddress cusAdress) { 
    this.status = status; 
    this.price = price; 
    this.customer = customer; 
    this.time = time; 
    this.lineItems = lineItems; 
    this.subOrders = subOrders; 
    this.cusAdress = cusAdress; 
} 


public Date getTime() { 
    return time; 
} 

public void setTime(Date time) { 
    this.time = time; 
} 

public List<ItemsNum> getLineItems() { 
    return lineItems; 
} 

public void setLineItems(List<ItemsNum> lineItems) { 
    this.lineItems = lineItems; 
} 

public List<OrdersNum> getSubOrders() { 
    return subOrders; 
} 

public void setSubOrders(List<OrdersNum> subOrders) { 
    this.subOrders = subOrders; 
} 



public String getStatus() { 
    return status; 
} 

public void setStatus(String status) { 
    this.status = status; 
} 

public float getPrice() { 
    return price; 
} 

public void setPrice(float price) { 
    this.price = price; 
} 

public CusAddress getCusAdress() { 
    return cusAdress; 
} 

public void setCusAdress(CusAddress cusAdress) { 
    this.cusAdress = cusAdress; 
} 



// //////////// Inner-Classes 


public class Customer { 

    @SerializedName("avatar_url") 
    @Expose 
    private String cusPicURL; //avatar_url 

    @SerializedName("first_name") 
    @Expose 
    private String firstName; //first_name 

    @SerializedName("last_name") 
    @Expose 
    private String lastName; //last_name 

    public String getCusPicURL() { 
     return cusPicURL; 
    } 

    public void setCusPicURL(String cusPicURL) { 
     this.cusPicURL = cusPicURL; 
    } 

    public String getFirstName() { 
     return firstName; 
    } 

    public void setFirstName(String firstName) { 
     this.firstName = firstName; 
    } 

    public String getLastName() { 
     return lastName; 
    } 

    public void setLastName(String lastName) { 
     this.lastName = lastName; 
    } 
} 

public class CusAddress { 

    public String getAddress() { 
     return address; 
    } 

    public void setAddress(String address) { 
     this.address = address; 
    } 

    public String getCity() { 
     return city; 
    } 

    public void setCity(String city) { 
     this.city = city; 
    } 

    public String getState() { 
     return state; 
    } 

    public void setState(String state) { 
     this.state = state; 
    } 

    public String getCountry() { 
     return country; 
    } 

    public void setCountry(String country) { 
     this.country = country; 
    } 

    @SerializedName("address_1") 
    @Expose 
    public String address; 

    @SerializedName("city") 
    @Expose 
    public String city; 

    @SerializedName("state") 
    @Expose 
    public String state; 

    @SerializedName("country") 
    @Expose 
    public String country; 
} 

public class ItemsNum { 

    @SerializedName("id") 
    @Expose 
    public Integer id; 
} 

public class OrdersNum { 

    @SerializedName("id") 
    @Expose 
    public Integer id; 
} 
} 

---

我的适配器

public class OrdersDataAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { 


public Context context; 
private int num; 
ArrayList<Order> orders; 


public OrdersDataAdapter(ArrayList<Order> orders, Context context) { 
    this.orders = orders; 

    this.context = context; 
} 

@Override 
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 

    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.order_card, parent, false); 

    return new NewOrderVH(v); 

} 


@Override 
public void onBindViewHolder(final RecyclerView.ViewHolder holder, final int position) { 
    final Order order = this.orders.get(position); 
    final NewOrderVH vh1 = (NewOrderVH) holder; 
    vh1.setData(orders.get(position)); 

} 

@Override 
public int getItemCount() { 
    return orders.size(); 
} 


public class NewOrderVH extends RecyclerView.ViewHolder { 


    private ImageView cusPic; 
    private TextView cusName; 
    private TextView CusAdress; 
    private TextView vendorsNum; 
    private TextView itemsNum; 
    private TextView time; 


    public NewOrderVH(View itemView) { 
     super(itemView); 


     orderCard = (CardView) itemView.findViewById(R.id.OrderCard); 
     cusPic = (ImageView) itemView.findViewById(R.id.cusPic); 
     cusName = (TextView) itemView.findViewById(R.id.cusName); 
     CusAdress = (TextView) itemView.findViewById(R.id.CusAdress); 
     vendorsNum = (TextView) itemView.findViewById(R.id.vendorsNum); 
     itemsNum = (TextView) itemView.findViewById(R.id.itemsNum); 
     time = (TextView) itemView.findViewById(R.id.time); 


    } 

    public void setData(final Order data) { 


     cusName.setText(data.customer.getFirstName() + "" + data.customer.getLastName()); 
     Picasso.with(context).load(data.customer.getCusPicURL()).into(cusPic); 
     time.setText(data.getTime().getMinutes()); 
     vendorsNum.setText(data.getSubOrders().size()); 
     itemsNum.setText(data.getLineItems().size()); 
     CusAdress.setText(data.cusAdress.getAddress() + "" + data.cusAdress.getCity() + "" + data.cusAdress.getCountry() + "" + data.cusAdress.getState()); 

    } 


} 

}片段内

请求方法

private void fetchPosts() { 


    requestQueue = Volley.newRequestQueue(getActivity()); 

    StringRequest jRequest = new StringRequest(Request.Method.GET, ENDPOINT, onPostsLoaded, onPostsError); 

    requestQueue.add(jRequest); 

} 


private final Response.Listener<String> onPostsLoaded = new Response.Listener<String>() { 
    @Override 
    public void onResponse(String response) { 

     Gson gson = new Gson(); 
     Type listType = new TypeToken<List<Order>>() {}.getType(); 
     modelData = gson.fromJson(response, listType); 


     adapter = new OrdersDataAdapter((ArrayList<Order>) modelData, getActivity()); 
     recyclerView.setAdapter(adapter); 
     adapter.setMode(Attributes.Mode.Single); 

    } 
}; 

private final Response.ErrorListener onPostsError = new Response.ErrorListener() { 
    @Override 
    public void onErrorResponse(VolleyError error) { 
     Log.e("PostActivity", error.toString()); 
    } 
}; 

Answer 1

这里你的问题是orders对象。你不反序列化orders。你能解决这个问题

public class OrderHolder{ 
    private List<Order> orders; 

    public List<Order> getOrders(){ return orders; } 

} 

OrderHolder holder = new Gson().fromJson(response, OrderHolder.class); 
modelData = holder.getOrders(); 

或

JsonElement jelement = new JsonParser().parse(response); 
JsonObject jobject = jelement.getAsJsonObject(); 
String ordersString = jobject.get("orders").getAsString(); 

Gson gson = new Gson(); 
Type listType = new TypeToken<List<Order>>() {}.getType(); 
modelData = gson.fromJson(ordersString, listType); 

Answer 2

预计BEGIN_ARRAY但路线是BEGIN_OBJECT 1列2路$

这很容易阅读：这意味着你解析类似于列表的东西（因此预计BEGIN_ARRAY[），但给定的JSON文档以BEGIN_OBJECT开头，这是由不匹配的预期类型引起的。它发生在JSON文档的开头。

除了mismanc的answer，还有一个第三方式，这需要一个稍微代码（可以提取到的方法虽然），但它并不需要两个包装或类似JsonElement和中间JSON树它的子类（第一种情况可能会消耗更多的内存，第二种情况肯定会消耗更多的内存，因为整个JSON树必须存储在内存中）。

// JsonReader allows to read JSON token stream 
try (final JsonReader jsonReader = new JsonReader(new StringReader(JSON))) { 
    // Just skip the leading `{` 
    jsonReader.beginObject(); 
    // Check if the next property name is what we're expecting 
    final String name = jsonReader.nextName(); 
    if (!name.equals("orders")) { 
     throw new MalformedJsonException("Unexpected: " + name); 
    } 
    // If it's fine, then we: 
    // * are assuming the JsonReader "pointer" is at the property value now 
    // * are asking Gson for the proper type adapter 
    @SuppressWarnings("unchecked") 
    final TypeAdapter<List<Order>> typeAdapter = (TypeAdapter<List<Order>>) gson.getAdapter(TypeToken.get(orderListType)); 
    // Just read the orders 
    final List<Order> orders = typeAdapter.read(jsonReader); 
    System.out.println(orders); 
} 

POJO自动转换器/生成器的JSON模式并不总是创建最佳映射。例如：

• 两者ItemsNum和OrdersNum由相同POJO结构表示，但是它可以是final class Id { @SerializedName("id") final Integer id = null; }。
• 客户avatar_url表示为java.lang.String，但它也可以是java.net.URL。

小笔记：不需要创建每次需要反序列化时

• Gson类的实例。它们完全是线程安全的，可以实例化一次，然后轻松重用。另外，创建并配置其他Gson实例可以被注入到你的代码中。
• Type使用TypeToken生成的实例可以被视为不可变的值对象，因此也可以缓存到static final字段中。

Answer 3

这里是正确的答案，我使用错误类型的请求..！

JsonObjectRequest jsObjRequest = new  
    JsonObjectRequest(Request.Method.GET,ENDPOINT,null, 
      new Response.Listener<JSONObject>() { 
       @Override 
       public void onResponse(JSONObject response) { 

        Gson gson = new Gson(); 
        Type listType = new TypeToken<List<Order>>() {}.getType(); 
        try { 

         List<Order> o = new ArrayList<>(); 
         o = gson.fromJson(response.getJSONArray("orders").toString(), listType); 
         if(o != null && !o.isEmpty()){ 

          modelData.addAll(o); 
          adapter.notifyDataSetChanged(); 
         } 

        } catch (JSONException e) { 
         e.printStackTrace(); 
        } 

       } 
      }, 
      new Response.ErrorListener() { 
       @Override 
       public void onErrorResponse(VolleyError error) { 

       } 
      }); 

    requestQueue.add(jsObjRequest); 

}