ChatGPT：使用fastjson读取JSON数据问题——如何使用com.alibaba.fastjson库读取JSON数据的特定字段

有一段Json字符串：

{"code": 200,"message": "success","data": {"total": "1","list": [{"question_no": "215202","question_stem": "师生进入生化类实验室工作，一定要搞清楚（　）等位置，出现情况能做好相应的自救工作。","v_establish_date": "2021-07-02","professional_level_id": "01","professional_level": "通识类","knowledge_point_id": "71","knowledge_point": "实验室安全","question_type_id": "01","question_type": "单选题","user_id": null,"user_name": null,"q_college": "学校","q_college_id": "%","numrow": "1","act": {"questionDelete": "删除","questionModify": "修改","getQuestionDetail": "查看","copyQuestion": "复制到本单位题库"}}]}
}

怎么结合com.alibaba的fastjson读取到question_no？

ChatGPT：

要使用阿里巴巴的FastJSON库来解析JSON字符串并提取其中的question_no字段，您需要按照以下步骤进行操作：

1. 导入FastJSON库。

2. 使用FastJSON的JSONObject来解析JSON字符串。

3. 获取data字段对应的JSONObject。

4. 获取list字段对应的JSONArray。

5. 获取数组中的第一个元素，然后获取其中的question_no字段。

以下是示例代码：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;public class Main {public static void main(String[] args) {String jsonString = "{\n" +"    \"code\": 200,\n" +"    \"message\": \"success\",\n" +"    \"data\": {\n" +"        \"total\": \"1\",\n" +"        \"list\": [\n" +"            {\n" +"                \"question_no\": \"215202\",\n" +"                \"question_stem\": \"师生进入生化类实验室工作，一定要搞清楚（　）等位置，出现情况能做好相应的自救工作。\",\n" +"                \"v_establish_date\": \"2021-07-02\",\n" +"                \"professional_level_id\": \"01\",\n" +"                \"professional_level\": \"通识类\",\n" +"                \"knowledge_point_id\": \"71\",\n" +"                \"knowledge_point\": \"实验室安全\",\n" +"                \"question_type_id\": \"01\",\n" +"                \"question_type\": \"单选题\",\n" +"                \"user_id\": null,\n" +"                \"user_name\": null,\n" +"                \"q_college\": \"学校\",\n" +"                \"q_college_id\": \"%\",\n" +"                \"numrow\": \"1\",\n" +"                \"act\": {\n" +"                    \"questionDelete\": \"删除\",\n" +"                    \"questionModify\": \"修改\",\n" +"                    \"getQuestionDetail\": \"查看\",\n" +"                    \"copyQuestion\": \"复制到本单位题库\"\n" +"                }\n" +"            }\n" +"        ]\n" +"    }\n" +"}";// 使用FastJSON解析JSON字符串JSONObject jsonObject = JSON.parseObject(jsonString);// 获取data字段对应的JSONObjectJSONObject dataObject = jsonObject.getJSONObject("data");// 获取list字段对应的JSONArrayJSONArray listArray = dataObject.getJSONArray("list");// 获取数组中的第一个元素JSONObject firstElement = listArray.getJSONObject(0);// 获取question_no字段的值String questionNo = firstElement.getString("question_no");System.out.println("question_no: " + questionNo);}
}

上述代码将打印出question_no字段的值"215202"。您可以根据实际需求进行进一步处理或存储。确保在项目中导入FastJSON库以使上述代码正常工作。

得到的Json字符串是这样的怎么办？

{"code":200,"message":"success","data":{"total":"1","list":[{"question_no":"215202","question_stem":"\u5e08\u751f\u8fdb\u5165\u751f\u5316\u7c7b\u5b9e\u9a8c\u5ba4\u5de5\u4f5c\uff0c\u4e00\u5b9a\u8981\u641e\u6e05\u695a\uff08\u3000\uff09\u7b49\u4f4d\u7f6e\uff0c\u51fa\u73b0\u60c5\u51b5\u80fd\u505a\u597d\u76f8\u5e94\u7684\u81ea\u6551\u5de5\u4f5c\u3002","v_establish_date":"2021-07-02","professional_level_id":"01","professional_level":"\u901a\u8bc6\u7c7b","knowledge_point_id":"71","knowledge_point":"\u5b9e\u9a8c\u5ba4\u5b89\u5168","question_type_id":"01","question_type":"\u5355\u9009\u9898","user_id":null,"user_name":null,"q_college":"\u5b66\u6821","q_college_id":"%","numrow":"1","act":{"questionDelete":"\u5220\u9664","questionModify":"\u4fee\u6539","getQuestionDetail":"\u67e5\u770b","copyQuestion":"\u590d\u5236\u5230\u672c\u5355\u4f4d\u9898\u5e93"}}]}}

ChatGPT：

您提供的JSON字符串包含Unicode编码字符，这是一种在JSON中表示特殊字符的方式。在FastJSON中，您可以使用JSON.parseObject方法来解析这样的JSON字符串，FastJSON会自动处理Unicode编码字符。

以下是如何解析包含Unicode编码字符的JSON字符串的示例代码：

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;public class Main {public static void main(String[] args) {String jsonString = "{\"code\":200,\"message\":\"success\",\"data\":{\"total\":\"1\",\"list\":[{\"question_no\":\"215202\",\"question_stem\":\"\\u5e08\\u751f\\u8fdb\\u5165\\u751f\\u5316\\u7c7b\\u5b9e\\u9a8c\\u5ba4\\u5de5\\u4f5c\\uff0c\\u4e00\\u5b9a\\u8981\\u641e\\u6e05\\u695a\\uff08\\u3000\\uff09\\u7b49\\u4f4d\\u7f6e\\uff0c\\u51fa\u73b0\u60c5\u51b5\u80fd\u505a\u597d\u76f8\u5e94\u7684\u81ea\u6551\u5de5\u4f5c\\u3002\",\"v_establish_date\":\"2021-07-02\",\"professional_level_id\":\"01\",\"professional_level\":\"\\u901a\\u8bc6\\u7c7b\",\"knowledge_point_id\":\"71\",\"knowledge_point\":\"\\u5b9e\\u9a8c\\u5ba4\\u5b89\\u5168\",\"question_type_id\":\"01\",\"question_type\":\"\\u5355\\u9009\\u9898\",\"user_id\":null,\"user_name\":null,\"q_college\":\"\\u5b66\\u6821\",\"q_college_id\":\"%\",\"numrow\":\"1\",\"act\":{\"questionDelete\":\"\\u5220\\u9664\",\"questionModify\":\"\\u4fee\\u6539\",\"getQuestionDetail\":\"\\u67e5\\u770b\",\"copyQuestion\":\"\\u590d\\u5236\\u5230\\u672c\\u5355\\u4f4d\\u9898\\u5e93\"}}]}}";// 使用FastJSON解析JSON字符串JSONObject jsonObject = JSON.parseObject(jsonString);// 获取data字段对应的JSONObjectJSONObject dataObject = jsonObject.getJSONObject("data");// 获取list字段对应的JSONArrayJSONArray listArray = dataObject.getJSONArray("list");// 获取数组中的第一个元素JSONObject firstElement = listArray.getJSONObject(0);// 获取question_no字段的值String questionNo = firstElement.getString("question_no");System.out.println("question_no: " + questionNo);}
}

这个示例代码会正确解析包含Unicode编码字符的JSON字符串，并提取question_no字段的值。再次提醒确保在项目中导入FastJSON库。