Question

我的服务是JSONArray。我想将此JSONArray转换为JavaObjects（使用POJO类）。我使用Jackson API进行JSON到JavaObject的转换。我还为该转换编写了辅助类（类名：JsonUtil）。

请在下面找到我的JSON响应，包含JSONObjects和JSONArray。

[  
       {  
          "order_number":"1000123",
          "customer_name":"Johnson Controls - ISC"
          "order_items":[  
             {  
                "line_number":"1",
                "product_code":"YMPA0100|Base",
                "product_description":"YMPA0100",
                "line_id":"c435d1bf-f9d4-47e6-b867-cda612429a6f",
                "product_quantity":1
             },
             {  
                "line_number":"1",
                "product_code":"YMPA0100|Base",
                "product_description":"YMPA0100",
                "line_id":"c435d1bf-f9d4-47e6-b867-cda612429a6f",
                "product_quantity":2
             },
             {  
                "line_number":"1",
                "product_code":"YMPA0100|Base",
                "product_description":"YMPA0100",
                "line_id":"c435d1bf-f9d4-47e6-b867-cda612429a6f",
                "product_quantity":2
             }
          ],

       }
]

从此，如果没有呈现order_items数组，我能够转换。如果出现order_items数组，则意味着它会抛出以下错误。

错误：将JSON转换为Java Objects时发生异常无法从START_OBJECT令牌中反序列化java.util.ArrayList的实例在[来源：java.io.StringReader@3444d69d; line：1，column：352]（通过引用链：com.util.OrderHeader [＆＃34; order_items＆＃34;]）

请在下面找到我的客户代码：

public class Demo {
    public static <Order> void main(String[] args)  {
        Client client = Client.getInstance();
        client.start();
        String findOrderString = 
        client.findOrder("","1000123",").toString();
        String result = findOrderString.replaceAll("[\\[\\] ]","");
        System.out.println("JsonString:::"+result);

        OrderHeader so=JsonUtil.convertJsonToJava(result, 
        OrderHeader.class);
      System.out.println("==>"+so.getCustomer_name()+",
      "+so.getOrder_number());
    }

OrderHeader POJO课程：

public class OrderHeader {

    String order_number;
    String customer_name;

    List<OrderItem> order_items;
    //Setters & Getters method

}

OrderItem POJO类:(应该是OrderHeader POJO类中的JSONArray）

public class OrderItem {

    String line_id;
    String line_number;
    String product_code;
    String product_description; 
    Long product_quantity;  

    //Getters & Setters method

}

请找到我的帮助类将JSON转换为JavaObject

public class JsonUtil {

    private static ObjectMapper mapper;
    static{
        mapper=new ObjectMapper();
    }


    public static <T> T convertJsonToJava(String jsonString, Class<T> cls)
    {
        T result=null;
        try {
            result=mapper.readValue(jsonString, cls);
        } catch (JsonParseException e) {
            System.out.println("Exception occured while converting JSON into 
            Java Objects"+e.getMessage());

        return result;

    }
}

Answer 1

您可以如下使用ObjectMapper：

private ObjectMapper objectMapper = new ObjectMapper();

List<Event> events = readValue(jsonString, new TypeReference<List<Event>>() {});

当然，您需要将其包装在try catch块中。

使用Jackson API将JSONObjects转换为JavaObjects。将JSONArray转换为java对象时出现问题

1 个答案: