將 JSON 數組映射到 Java POJO

Question

我將如何將此 JSON 映射到對象？

{"d":"[{\"Key\":\"3\",\"ExternalKey\":\"143234A\",\"Name\":\"cup of juice\",\"Litres\":\"2 litres\",\"Date\":\"2016-10-06T08:32:27\",\"Capacity\":5.4900,\"CapacityType\":\"%\"}, {\"Key\":\"3\",\"ExternalKey\":\"143234A\",\"Name\":\"cup of milk\",\"Litres\":\"2.4 litres\",\"Date\":\"2016-10-06T08:32:27\",\"Capacity\":1667.6100,\"CapacityType\":\"M\"}]"}

我試過使用 HashMap，但它只是將“d”作為字符串，其余的作為帶有一個元素的 String 對象

Answer 1

您的 Json 字符串有一些額外的 " 字符。

這是最終的json：

{
  "d": [
    {
      "Key": "3",
      "ExternalKey": "143234A",
      "Name": "cup of juice",
      "Litres": "2 litres",
      "Date": "2016-10-06T08:32:27",
      "Capacity": 5.49,
      "CapacityType": "%"
    },
    {
      "Key": "3",
      "ExternalKey": "143234A",
      "Name": "cup of milk",
      "Litres": "2.4 litres",
      "Date": "2016-10-06T08:32:27",
      "Capacity": 1667.61,
      "CapacityType": "M"
    }
  ]
}

現在您可以復制 json 並將其粘貼到此處以獲取 pojo。

Answer 2

這是一個非常常見的問題，稱為數據封送處理。 在 Java 中，Jackson 是通用的最佳解決方案。 閱讀本教程： http : //wiki.fasterxml.com/JacksonInFiveMinutes

Answer 3

There are n numbers of libraries available for parsing the JSON and convert into in java classes.

Some of the examples are,

GSON
Jackson
Logan Square
Moshi, etc

You need to create a java class which map with your JSON Response and need to change your pojo according to parsing library.

For Example, 

Using Logan Square you must annotate your POJO class to @JsonObject and all properties must be annotated with @JsonField.

Now, you can parse your json using method 

...
LoganSquare.parse(jsonString, pojoClassName);
...

Hopefully this will help you.

Cheers

Answer 4

如果我將“d”鍵子串出來並將其映射為 JSON 數組，那么它就可以工作了，這將是現在的解決方案......