java - 当我获取 JSON 元素时为空值

Question

我正在通过 REST API 自动创建事件。在读取 JSON 元素时，我得到了 null 值，我使用相同的逻辑使用 Rapid7 启动 Scan，并且工作正常。

JSON

服务器确实返回具有正确属性的 JSON。但按名称获取属性返回 null。有人能发现这里出了什么问题吗？谢谢

//阅读

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8));
String lines = null;
StringBuilder stringBuilder = new StringBuilder();
while ((lines = bufferedReader.readLine()) != null) {
    stringBuilder.append(lines);
}
bufferedReader.close();
result = stringBuilder.toString();
JSONParser parser = new JSONParser();
JSONObject json = (JSONObject) parser.parse(result); // this works fine I can see all JSON elements ( incident_number, Sys_id, state, ect )

if (method.equals("GET")) {
    String incident_state = json.get("state").toString();
    System.out.print(incident_state);
    incident.setState(Integer.parseInt(incident_state));
    System.out.print("\n ServiceNow : Successful GET, incident is retrieved" );
}

我在 Rapid7 中使用了相同的逻辑并且工作得很好

//Read
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8));
String lines = null;
StringBuilder stringBuilder = new StringBuilder();
while ((lines = bufferedReader.readLine()) != null) {
    stringBuilder.append(lines);
}
bufferedReader.close();
result = stringBuilder.toString();

JSONParser parser = new JSONParser();
JSONObject json2 = (JSONObject) parser.parse(result);


if(methodType == MethodType.Retrieve_Vulnerability_info) {
    String scan_vuln_title= json2.get("title").toString();
    String scan_vuln_severityScore = json2.get("severityScore").toString();
    String scan_vuln_publishe_date = json2.get("published").toString();
    String scan_vuln_descriptiob = json2.get("description").toString() + splunkdata.getNmap_results();
    splunkdata.getScan().getList_of_found_Vulnerabilties().get(Vulnerability_id).setSeverityScore(scan_vuln_severityScore);
    splunkdata.getScan().getList_of_found_Vulnerabilties().get(Vulnerability_id).setVulnerability_title(scan_vuln_title);
    splunkdata.getScan().getList_of_found_Vulnerabilties().get(Vulnerability_id).setPublished_date(scan_vuln_publishe_date);
    splunkdata.getScan().getList_of_found_Vulnerabilties().get(Vulnerability_id).setDescription(scan_vuln_descriptiob);
    System.out.print("\n Rapid7 : Successful GET,  vulnerabilities info of : "+ scan_vuln_title + " were retrieved" );

}

Json 作为字符串:

{
    "result": {
        "promoted_by": "",
        "parent": "",
        "caused_by": "",
        "watch_list": "",
        "upon_reject": "cancel",
        "sys_updated_on": "2019-05-17 14:01:56",
        "u_validation_contact": "",
        "approval_history": "",
        "skills": "",
        "number": "INC2090774",
        "proposed_by": "",
        "lessons_learned": "",
        "state": "2",
        "sys_created_by": "sa_security",
        "knowledge": "false",
        "order": "",
        "cmdb_ci": "",
        "u_supplier_reference": "",
        "impact": "2",
        "active": "true",
        "work_notes_list": "",
        "priority": "4",
        "sys_domain_path": "/",
        "u_impacted_services": "",
        "business_duration": "",
        "group_list": "",
        "u_phone_validating": "",
        "approval_set": "",
        "major_incident_state": "",
        "short_description": "test",
        "correlation_display": "",
        "work_start": "",
        "additional_assignee_list": "46cfdce9db7157046ada1ded0b961990,4cff106ddb7157046ada1ded0b961905,2cb1adc2db9d7b803111f2603996197f",
        "notify": "2",
        "sys_class_name": "incident",
}
}

Answer 1

问题是我必须更深入一步，然后检索结果。 感谢 Austin Schafter 的建议。

  bufferedReader.close();
                result = stringBuilder.toString();
                JSONParser parser = new JSONParser();
                JSONObject json = (JSONObject) parser.parse(result);
                JSONObject JsonResults = (JSONObject) json.get("result"); // here where the change needed 
 if (method.equals("GET"))
                {
                    String incident_state = JsonResults.get("state").toString(); // then use JSON which store results to retrieve other JSON elements by using name
                    System.out.print(incident_state);
                    incident.setState(Integer.parseInt(incident_state));
                    System.out.print("\n ServiceNow : Successful GET, incident is retrieved" );
                }