将JSON数组转换为Java类对象列表

我有一个来自WFC服务的JSON字符串。当我尝试将JSON数组转换为List对象时，出现以下错误：

".JsonMappingException: Can not deserialize instance of java.util.ArrayList out of START_OBJECT token at [Source: java.io.StringReader@41f27f18; line: 1, column: 1]"

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

Java类（卡片类）：

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

要反序列化的Java代码：

strResponse = responseHandler.handleResponse(response);
if (strResponse.contains("Credit") || strResponse.contains("Debit")) {
    ObjectMapper mapper = new ObjectMapper();
    strResponse= strResponse.replace("\"GetCardsResult\":", "");
    userCards = mapper.readValue(strResponse, mapper.getTypeFactory().constructCollectionType(List.class, Card.class));
}

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

JSON字符串：

{     "GetCardsResult":"[{\"ID\":3,\"CompanyID\":1155,\"CompanyName\":\"test\",\"FiscalCode\":null,\"Code\":\"1423127205\",\"Limit\":0.000,\"StateID\":1,\"CardState\":\"Activ\",\"Deleted\":false,\"Sold\":0.000,\"StartDate\":\"\/Date(1412974800000+0300)\/\",\"InvoiceStartDate\":\"\/Date(-62135596800000+0200)\/\",\"Quantity\":null,\"Value\":0.0,\"CardTypeID\":1,\"CardType\":\"Credit\",\"SoldChanged\":false,\"DriverName\":\"\",\"VehiclePlateNumber\":\"B 222 ART\",\"VehicleID\":null,\"Discount\":null,\"ContractID\":15,\"DiscountPerMonth\":null,\"ProductID\":null,\"ProductStateID\":null,\"Mail\":\"\",\"WithoutLimit\":true,\"ContractSold\":null,\"ContractLimit\":null,\"NumberOfTransactions\":null,\"DriverNameOnly\":null,\"DriverSurnameOnly\":null},{\"ID\":2881,\"CompanyID\":1155,\"CompanyName\":\"test\",\"FiscalCode\":null,\"Code\":\"test0000\",\"Limit\":125.000,\"StateID\":1,\"CardState\":\"Activ\",\"Deleted\":false,\"Sold\":132.330,\"StartDate\":\"\/Date(1436130000000+0300)\/\",\"InvoiceStartDate\":\"\/Date(-62135596800000+0200)\/\",\"Quantity\":null,\"Value\":0.0,\"CardTypeID\":1,\"CardType\":\"Credit\",\"SoldChanged\":false,\"DriverName\":\"aaa aaa\",\"VehiclePlateNumber\":\"aaa\",\"VehicleID\":null,\"Discount\":null,\"ContractID\":15,\"DiscountPerMonth\":null,\"ProductID\":null,\"ProductStateID\":null,\"Mail\":\"\",\"WithoutLimit\":true,\"ContractSold\":null,\"ContractLimit\":null,\"NumberOfTransactions\":null,\"DriverNameOnly\":null,\"DriverSurnameOnly\":null}]" }

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

---

提前谢谢

试试这个：

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

试试{
JSONObject JSONObject=null；
替换（“\\”，“”）；
jsonObject=新的jsonObject（您的JSONString）；
字符串newJSONString=jsonObject.get（“GetCardsResult”）.toString（）；
JSONArray-jsonMainArr=newjsonarray（newJSONString）；
//现在只需循环json数组
对于（inti=0；i

在编译正则表达式之前或之后，向映射器字符串传递什么

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

您是否尝试过任何像Gson这样的外部库？您需要的只是

new Gson（）.fromJson（strResponse，new TypeToken（）{}.getType（）；）

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

---

尝试使用GSON，因为它非常高效且易于实现，下面的示例将是您的POJO类

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

public class Post {

    @SerializedName("id")
    public long ID;
    public String title;
    public String author;
    public String url;
    @SerializedName("date")
    public Date dateCreated;
    public String body;

    public List tags;

    public Post() {

    }
}

//Tag.java
public class Tag {

    public String name;
    public String url;

    public Tag() {

    }
}

这将说明如何将JSON字符串解析为对象类

    try {            
         JSONObject jsonObject = null;
         yourJSONString.replace("\\", "");
         jsonObject = new JSONObject(yourJSONString);
         String newJSONString = jsonObject.get("GetCardsResult").toString();
         JSONArray jsonMainArr = new JSONArray(newJSONString);
         //now just loop the json Array
         for (int i = 0; i < jsonMainArr.length(); ++i) {                     
         JSONObject rec = jsonMainArr.getJSONObject(i);                     
         card.set_id(rec.get("ID").toString());                     
         //....      
       }                                                       
       } catch (JSONException e) {
         e.printStackTrace();
       } 

Reader reader = new InputStreamReader(content);
GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.setDateFormat("M/d/yy hh:mm a");
Gson gson = gsonBuilder.create();
List<Post> posts = new ArrayList<Post>();
posts = Arrays.asList(gson.fromJson(reader, Post[].class));
content.close();

Reader Reader=新的InputStreamReader（内容）；
GsonBuilder GsonBuilder=新的GsonBuilder（）；
gsonBuilder.setDateFormat（“M/d/yy hh:mm a”）；
Gson-Gson=gsonBuilder.create（）；
List posts=new ArrayList（）；
posts=Arrays.asList（gson.fromJson（reader，Post[].class））；
content.close（）；

如何将json字符串转换为对象类？我以为ObjectMapper会这样做：）这就是为什么我所有的类变量都是Strings我猜他在使用com.fasterxml.jackson.databind.ObjectMapper.org.json.JSONObject<代码>strResponse=strResponse.replace（“\”GetCardsResult\”：“，”）将破坏您的JSON。您只删除了键和冒号，而不是前面和后面的大括号。另外：您的代码效率很低（最多需要处理四次字符串），并且可能会中断（例如，Web服务返回格式化的JSON，冒号前面有一个空格），userCards=gs.fromJson（strResponse，new-TypeToken（）{}.getType（））；java.lang.IllegalStateException：应为BEGIN_数组，但在第1行第2列为BEGIN_对象，那么new Gson（）如何从JSON（strResponse，Card.class）开始呢；你以为有一个对象，而不是数组？不能将数组转换为卡片对象。当然，JSON响应中有一个数组。有不止一个卡片信息，所以，我需要数组，只要我以某种方式通过objectLet转换对象。