Question

我从休息服务器接收此json作为响应：

{  
   "externalOrderId":"5cb9bc46-aaa3-43ff-bb1a-6b17443f63ea",
   "shortId":null,
   "createdAt":1442255497402,
   "updatedAt":1442255497402,
   "cart":{  
      "id":"gy4ectxb3db84epljzhisqrf"
   }
}

然后，当我尝试使用gson.fromJson解析这个json时，我收到错误：

java.lang.IllegalStateException: Expected BEGIN_OBJECT but was NUMBER at line 1 column 201 path $.createdAt

这是我如何做到的：

public Order getOrder(String externalOrderId) throws Exception {
        HttpRequest request = new HttpRequestBuilder()
            .setUrl(new URI(baseURL + "/order/" + externalOrderId))
            .build();

        return gson.fromJson(HttpResource.getInstance().get(request).getBody(), new TypeToken<Order>(){}.getType());
    }

订单对象：

private String externalOrderId;
private Long shortId;
private Date createdAt;
private Date updatedAt;

提前致谢。

Answer 1

您的createdAt和updatedAt字段是Date个对象，而JSON数据有数字。为了能够与数字匹配，您需要createdAt和updatedAt也是Long s，然后将它们转换为Date个对象。< / p>

Answer 2

试试这个（参见Order.java中的toString和longToDate方法） -

<强> Cart.java

public class Cart {
    private String id;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "Cart [id=" + id + "]";
    }
}

<强> Order.java

import java.util.Date;

public class Order {
    private String externalOrderId;
    private Long shortId;
    private Long createdAt;
    private Long updatedAt;
    private Cart cart;
    public String getExternalOrderId() {
        return externalOrderId;
    }
    public void setExternalOrderId(String externalOrderId) {
        this.externalOrderId = externalOrderId;
    }
    public Long getShortId() {
        return shortId;
    }
    public void setShortId(Long shortId) {
        this.shortId = shortId;
    }

    public Long getCreatedAt() {
        return createdAt;
    }
    public void setCreatedAt(Long createdAt) {
        this.createdAt = createdAt;
    }
    public Long getUpdatedAt() {
        return updatedAt;
    }
    public void setUpdatedAt(Long updatedAt) {
        this.updatedAt = updatedAt;
    }
    public Cart getCart() {
        return cart;
    }
    public void setCart(Cart cart) {
        this.cart = cart;
    }

    private Date longToDate(Long dt) {
        return new Date(dt);
    }
    @Override
    public String toString() {
        return "Order [externalOrderId=" + externalOrderId + ", shortId="
                + shortId + ", createdAt=" + longToDate(createdAt) + ", updatedAt="
                + longToDate(updatedAt) + ", cart=" + cart + "]";
    }
}

<强> Main.java

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.testgson.beans.Order;

public class Main {
    private static Gson gson;

    static {
        gson = new GsonBuilder().create();
    }

    public static void main(String[] args) {
        String j = "{\"externalOrderId\":\"5cb9bc46-aaa3-43ff-bb1a-6b17443f63ea\",\"shortId\":null,\"createdAt\":1442255497402,\"updatedAt\":1442255497402,\"cart\":{\"id\":\"gy4ectxb3db84epljzhisqrf\"}}";
        Order r = gson.fromJson(j, Order.class);
        System.out.println(r);
    }
}

<强>结果

Order [externalOrderId=5cb9bc46-aaa3-43ff-bb1a-6b17443f63ea, shortId=null, createdAt=Tue Sep 15 00:01:37 IST 2015, updatedAt=Tue Sep 15 00:01:37 IST 2015, cart=Cart [id=gy4ectxb3db84epljzhisqrf]]

预计BEGIN_OBJECT但是为NUMBER

2 个答案: