我正在尝试存储我从第三方Web服务获取的JSON。问题是我得到了一个JSON数组。这些JSON也包含数组字段。我试图用Jackson和Simple Json解析JSON，但我不能。请帮忙。我可能忽略了导致这个问题的事情。
import java.io.BufferedReader;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.type.TypeReference;
import org.springframework.web.servlet.ModelAndView;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import javax.ws.rs.Produces;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.json.JSONArray;
import org.json.JSONObject;
@Controller
public class RecommendationController {
@RequestMapping(value = "/getResult.do", method = RequestMethod.POST)
@Produces("application/json")
@ResponseBody
public ArrayList<Map<String, Object>> getResults(@RequestBody SearchQuery searchQuery) throws Exception{
ArrayList<Map<String, Object>> response = sendPost(searchQuery);
String email=null;
ArrayList<Map<String, Object>> finalResult = new ArrayList<Map<String, Object>>();
for (Map<String, Object> map : response) {
Map<String, Object> temp = new HashMap<String, Object>();
if(map.containsKey("TutorID"))
temp.put("TutorID", map.get("TutorID"));
if(map.containsKey("Name"))
temp.put("Name", map.get("Name"));
if(map.containsKey("City"))
temp.put("City", map.get("City"));
if(map.containsKey("State"))
temp.put("State", map.get("State"));
if(map.containsKey("TutorPictures"))
temp.put("TutorPictures", map.get("TutorPictures[0]"));
if(map.containsKey("FeePerHour"))
temp.put("FeePerHour", map.get("FeePerHour"));
if(map.containsKey("StarRatingAverage"))
temp.put("StarRatingAverage", map.get("StarRatingAverage"));
if(map.containsKey("TutorID") & map.containsKey("State") & map.containsKey("City"))
email = "http://localhost:8080/TestPrecision/contactTutor.do"+"?State="+map.get("State")+"&City="+((String) map.get("City")).replaceAll(" ", "-")+"&TutorID="+map.get("TutorID");
temp.put("Email", email);
finalResult.add(temp);
}
return finalResult;
}
private ArrayList<Map<String,Object>> sendPost(SearchQuery searchQuery) throws Exception {
ArrayList<Map<String,Object>> responseDataMap = null;
String url = "http://data.wyzant.com/api/search";
URL obj = new URL(url);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
//add reuqest header
con.setRequestMethod("POST");
con.setRequestProperty("Accept", "application/json");
String searchUrl = "";
searchUrl = "&SearchString="+searchQuery.getMessageString()+"&Zip="+searchQuery.getMessageZip()+"&MaxResults="+searchQuery.getMessageMaxResult();
String urlParameters = "Your_Partner_Key&"+searchUrl;
// Send post request
con.setDoOutput(true);
DataOutputStream wr = new DataOutputStream(con.getOutputStream());
wr.writeBytes(urlParameters);
wr.flush();
wr.close();
int responseCode = con.getResponseCode();
System.out.println("\nSending 'POST' request to URL : " + url);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
/*StringBuilder responseStrBuilder = new StringBuilder();
String inputStr;
while ((inputStr = in.readLine()) != null)
responseStrBuilder.append(inputStr);
System.out.println(new JSONObject(responseStrBuilder.toString()));
*/ObjectMapper objectmapper = new ObjectMapper();
responseDataMap = objectmapper.readValue(in, new TypeReference<ArrayList<Map<String , Object>>>(){
});
System.out.println("JSON Map -----> /n"+responseDataMap);
in.close();
return responseDataMap;
}
}
以下是我从第三方Web服务
获得的JSON[
{
"TutorID":8304029,
"Name":"Matthew B.",
"City":"Fremont",
"State":"CA",
"Zip":"94538",
"Title":null,
"FeePerHour":60,
"FreeResponse":"...",
"TravelDistance":15,
"TutorPictures":[
"http://dj1hlxw0wr920.cloudfront.net/userfiles/wyzfiles/be0c64e4-be09-4b38-bbd8- 72f3843cadde.jpg"
],
"ProfileLink":"http://www.wyzant.com/Tutors/CA/Fremont/8304029/? utm_source=partners\u0026utm_medium=api\u0026utm_term=1229\u0026utm_campaign=407\u0026g=3SEQ",
"EmailLink":"http://www.wyzant.com/Tutors/CA/Fremont/8304029/Contact.aspx?utm_source=partners\u0026utm_medium=api\u0026utm_term=1229\u0026utm_campaign=407\u0026g=3SEQ",
"Subjects":[
{
"Name":"American history",
"Description":null
},
{
"Name":"vocabulary",
"Description":null
},
{
"Name":"reading",
"Description":null
},
{
"Name":"writing",
"Description":null
},
{
"Name":"English",
"Description":null
}
],
"Reviews":null,
"StarRatingAverage":null,
"StarRatingCount":null,
"TutorRank":0.55803185701370239,
"College":null
},
{
"TutorID":8347645,
"Name":"Taner O.",
"City":"Fremont",
"State":"CA",
"Zip":"94538",
"Title":null,
"FeePerHour":65,
"FreeResponse":"...",
"TravelDistance":5,
"TutorPictures":[
],
"ProfileLink":"http://www.wyzant.com/Tutors/CA/Fremont/8347645/?utm_source=partners\u0026utm_medium=api\u0026utm_term=1229\u0026utm_campaign=407\u0026g=3SEQ",
"EmailLink":"http://www.wyzant.com/Tutors/CA/Fremont/8347645/Contact.aspx?utm_source=partners\u0026utm_medium=api\u0026utm_term=1229\u0026utm_campaign=407\u0026g=3SEQ",
"Subjects":[
{
"Name":"calculus",
"Description":null
},
{
"Name":"chemistry",
"Description":null
},
{
"Name":"geometry",
"Description":null
},
{
"Name":"physics",
"Description":null
},
{
"Name":"SAT math",
"Description":null
}
],
"Reviews":null,
"StarRatingAverage":null,
"StarRatingCount":null,
"TutorRank":-0.39533111453056335,
"College":null
}
我打算从这个JSON获得Tutor Image，Tutor Name，Subjects，FeeperHour，StarRating。我已经成功获得了Tutor Name，FeesperHour和StarRatings，虽然无法检索Tutor Image和Subjects，因为它们进入阵列并且我无法解析它。请帮忙。下面是我设法获得的JSON。
[
{
"Name":"Courtney D.",
"FeePerHour":60,
"State":"NY",
"TutorPictures":null,
"StarRatingAverage":null,
"TutorID":7874994,
"City":"Milford"
}
]
答案 0 :(得分：2)
如果您不想使用类并反序列化到类，请不要尝试反序列化为Java类型，而是反序列化为JsonNode：
final JsonNode data = mapper.readTree(yourURLObject);
请参阅JsonNode的javadoc。您可以使用它轻松导航JSON。
例如，以下是如何从每个数组元素中打印出TutorID对象成员：
// This cycles through a JSON array's elements or a JSON Object's member values;
// empty iterator for all other JSON value types
for (final JsonNode element: data)
System.out.println(data.path("TutorID"));
答案 1 :(得分：1)
伪代码：
Class Tutor {
String tutorName;
String[] tutorPictures;
Subject[] subjects;
Number feePerHour;
Number starRating; // Not clear if this is number or string
}
Class Subject {
String name;
String description;
}
List mainList = parseJson(jsonBytes);
Tutor[] tutors = new Tutor[mainList.count()];
int tutorCount = 0;
for each Map tutorMap in tutors {
Tutor tutor = new tutor();
List tutorPicturesList = tutorMap.get("TutorPictures");
tutor.tutorPictures = tutorPicturesList.toStringArray(); // Or copy logic for subjects below
tutor.tutorName = tutorMap.get("Name");
List subjectsList = tutorMap.get("Subjects");
tutor.subjects = new Subjects[subjectsList.count()];
int subjectCount = 0;
for each Map subjectMap in mainList {
Subject subject = new Subject();
subject.name = subjectMap.get("Name");
subject.description = subjectMap.get("Description");
tutor.subjects[subjectCount] = subject;
subjectCount++;
}
tutor.feePerHour = tutorMap["FeePerHour"];
tutor.starRating = tutorMap["StarRating"];
tutors[tutorCount] = tutor;
tutorCount++;
}
根据所使用的工具集，必须将强制转换插入适当的类型或使用特定于类型的方法来提取Map元素。
对于任何可以为空的数字字段，必须将这些值作为对象进行检索，并且（如果需要）仅在非空时提取数值。