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：
-
导入FastJSON库。
-
使用FastJSON的JSONObject来解析JSON字符串。
-
获取data字段对应的JSONObject。
-
获取list字段对应的JSONArray。
-
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" +
"}";
JSONObject jsonObject = JSON.parseObject(jsonString);
JSONObject dataObject = jsonObject.getJSONObject("data");
JSONArray listArray = dataObject.getJSONArray("list");
JSONObject firstElement = listArray.getJSONObject(0);
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\"}}]}}";
JSONObject jsonObject = JSON.parseObject(jsonString);
JSONObject dataObject = jsonObject.getJSONObject("data");
JSONArray listArray = dataObject.getJSONArray("list");
JSONObject firstElement = listArray.getJSONObject(0);
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。
