将HashMap的ArrayList转换为JSON字符串[重复]

Question

我想将ArrayList<Hashmap<String,String>> 转换为JSONArray。我用过

JSONArray array = new JSONArray(array_list);

但它不能正常工作它返回

["{image=2130837526, category=Chairs, Quantity=1, price=400, name=chair, prodId=34}","{image=2130837566, category=Mirrors, Quantity=1, price=3000, name=La Fonda, prodId=35}"]

它应该返回

cartitems=[{"name":"Chair","price":"1001","prodId":"2","category":"Chairs","image":"2130837519","Quantity":"1"},{"name":"Baxton Studio Club Chair","price":"4545","prodId":"5","category":"Chairs","image":"2130837521","Quantity":"1"}]

Answer 1

有很多方法可以实现这一目标。我将解释两种方式：

你可以这样做：

ArrayList<HashMap<String, String>> dataMap = new ArrayList<HashMap<String, String>>();

HashMap<String, String> data1 = new HashMap<String, String>();
data1.put("image", "2130837526");
data1.put("category", "Chairs");
data1.put("Quantity", "1");

HashMap<String, String> data2 = new HashMap<String, String>();
data2.put("image", "2130837566");
data2.put("category", "Mirrors");
data2.put("Quantity", "2");

dataMap.add(data1);
dataMap.add(data2);


List<JSONObject> jsonObj = new ArrayList<JSONObject>();

for(HashMap<String, String> data : dataMap) {
    JSONObject obj = new JSONObject(data);
    jsonObj.add(obj);
}

JSONArray test = new JSONArray(jsonObj);

System.out.println(test.toString());

---

或者你可以使用 Jackson 对象映射器：

Download Jackson Core

Download Jackson Mapper

将外部库添加到 Eclipse 项目

Adding a library/JAR to an Eclipse Android project

Java 代码

ArrayList<HashMap<String, String>> dataMap = new ArrayList<HashMap<String, String>>();

HashMap<String, String> data1 = new HashMap<String, String>();
data1.put("image", "2130837526");
data1.put("category", "Chairs");
data1.put("Quantity", "1");

HashMap<String, String> data2 = new HashMap<String, String>();
data2.put("image", "2130837566");
data2.put("category", "Mirrors");
data2.put("Quantity", "2");

dataMap.add(data1);
dataMap.add(data2);

ObjectMapper objectMapper = new ObjectMapper();

String json = objectMapper.writeValueAsString(dataMap);

System.out.println(json);

两个选项都将打印：

[{"image":"2130837526","category":"Chairs","Quantity":"1"},{"image":"2130837566","category":"Mirrors","Quantity":"2"}]