parse and get specific field from HTTP response in java

parse and get specific field from HTTP response in java - java

I try to parse a HTTP response to a JSONObject and retrieve some fields, coould be a String or int.
My response is a json array like this:
[{nid: "24161",changed: 1445936169,created: "1444728767",language: "en",status: 1,title: "bicycle",type: "product",uid: "2172",vid: "24161"}]
And I tried using:
JSONObject myObject = new JSONObject(response);
And gson , still after parsing the response turns to {}.
Thanks for any help.

You must use JSONArray instead of JSONObject
JSONArray array = new JSONArray(response);
You can then iterate throw the array and get the fields you want
for(int i=0; i<array.length(); i++) {
JSONObject object = array.getJSONObject(i);
String nid = object.getString("nid");
int changed = object.getInt("changed");
//...
}

You are parsing json array into object. Use JSONArray instead of JSONObject
JSONArray myArray = new JSONArray(response);
you can get your object by index from your array.

Related

Can't parse some JSON into a JsonArray using GSON

I am trying to get the values from a JSON response. I got everything to work, except extracting an array from the following string:
{"o":"1.18988","h":"1.18993","l":"1.18963","c":"1.18993"}
I know GSON is trying to parse it because I get this error:
Exception in thread "main" java.lang.IllegalStateException: Not a JSON Array: {"o":"1.18988","h":"1.18993","l":"1.18963","c":"1.18993"}
I am using the following code to attempt to parse it:
final JsonElement midElement = obj.get("mid");
final JsonArray midArray = midElement.getAsJsonArray();
for(Object rate : midArray){
final JsonObject rateObj = (JsonObject)rate;
final JsonElement openElement = rateObj.get("o");
open = openElement.getAsFloat();
final JsonElement highElement = rateObj.get("h");
high = highElement.getAsFloat();
final JsonElement lowElement = rateObj.get("l");
low = lowElement.getAsFloat();
final JsonElement closeElement = rateObj.get("c");
close = closeElement.getAsFloat();
}

First of all it doesn't look like a valid JSON array. It should look like this
[{"o":"1.18988","h":"1.18993","l":"1.18963","c":"1.18993"}]
Try this following code to parse it in JSON format.
JSONObject jsonObject = new JSONObject(jsonString);
JSONArray jsonArray = jsonObject.getJSONArray("mid");
for (int i = 0; i < jsonArray.length(); i++) {
jsonArray.getJSONObject(i).getString("o");
}
Then convert it your preferred data form.

Json object to java arraylist

I have pass two values from ajax to my servlet.
I used
JsonObject data = new Gson().fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
and this is the output
{"0":"31/01/2017","1":"19/01/2017"}
Now I want to convert this data into a java arraylist but not really sure how.
I tried
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
JsonArray jsonArr = data.getAsJsonArray();
// jsonArr.
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i=0; i< jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}
But got an error
java.lang.IllegalStateException: This is not a JSON Array.
Someone help me please? thanks.

Create instance of JsonArray then add json element to that array using key.
Here is your solution :
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson(request.getReader(), JsonObject.class);
System.out.println(data);
JsonArray jsonArr = new JsonArray();
for(Entry<String, JsonElement> entry : data.entrySet()) {
jsonArr.add(data.get(entry.getKey()));
}
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i = 0; i < jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}

For a Json to be a valid JsonArray object you should have it to a proper format. Can you change your json string return from your ajax? If yes you should change it to something like this:
Gson googleJson = new Gson();
JsonObject data = googleJson.fromJson("{test: [{\"0\":\"31/01/2017\"},{\"1\":\"19/01/2017\"}]}", JsonObject.class);
System.out.println(data);
JsonArray jsonArr = data.getAsJsonArray("test");
ArrayList jsonObjList = googleJson.fromJson(jsonArr, ArrayList.class);
for(int i=0; i< jsonObjList.size(); i++) {
System.out.println(jsonObjList.get(i));
}
If not you should parse it by your self and convert it to everything you want.

Json Iterating using java

Here is my json Object.
{"id":"mrbbt6f3fa99gld0m6n52osge0",
"name_value_list":
{"user_default_dateformat":{"name":"user_default_dateformat","value":"m/d/Y"}},
"module_name":"Users"}
I got id,and module_name through following code.How can i get user_default_dateformat?.
I know it may so simple but I am a newbie in json.
String jsonResponse;
while ((jsonResponse = br.readLine()) != null) {
jsonOutput = jsonResponse;
}
JSONObject job = new JSONObject(jsonOutput);
System.out.println(job);// i can see the same json object
that i showen above.
sessionID = job.get("id").toString();
Exception generating coge
JSONObject job2=new JSONObject(job);
dateFormat = job2.get("user_default_dateformat").toString();
The Eexception is
org.json.JSONException: JSONObject["user_default_dateformat"] not found.
Thanks,

name_value_list is also an Object.
JSONObject job2 = new JSONObject(job.get("name_value_list"));
So there you get
job2.get("user_default_dateformat");
Every {} in your JSON is an object. So for every String you get which is something like {"xy":"za","ab":"cd"} you have to cast it to the JSONObject
Edit for your error:
As you can see in your code the line:
JSONObject job2=new JSONObject(job);
will try to generate a JSONObject out of your JSONObject.
You have to get the JSONObject in your JSONObject.
You want to get the user_default_dateformat which is in your JSONObject:
String name_value_list_string = job.get("name_value_list").toString();
//this string is another json-string which contains the user_default_dateformat
JSONObject name_value_list_object = new JSONObject(name_value_list_string);
//This JSONObject contains the user_default_dateformat but this is also a JSONObject
String user_default_dateformat_string = name_value_list_object.get("user_default_dateformat").toString();
//this String contains the user_default_dateformat JSONString
JSONObject user_default_dateformat_object = new JSONObject(user_default_dateformat_string);
//This JSONObject contains the String values of your user_default_dateformat

if you are using JSONSimple library you can use this:
jsonObject = (JSONObject) new JSONParser().parse(jsonstr);
System.out.println((JSONObject)jsonObject.get("name_value_list"))).get("user_default_dateformat"));
This should give you the required result.

parsing URL in String from JSON

1) I've got a JSON file:
{
"serverURI":"http://localhost:8080/PocketUNI_API/serverURLs",
"newsURI":"http://localhost:8080/gateway/rss/rss.xml",
"modulesURI":"http://localhost:8080/PocketUNI_API/modules"
}
2) I need to get URLs on Java client in String format.
String json = jsonReceiver.makeHttpRequest(URL_SERVER, "GET", params);
JSONArray uris = new JSONArray(json);
Receiver works fine and json shows the correct string received, but when it goes to parsing with JSONArray it throws an error
org.json.JSONException: Value {"serverURI":"http:\/\/192.168.0.... of type org.json.JSONObject cannot be converted to JSONArray.
Question: How to parse json with URL values?

You don't get a JSONArray but a JSONObject.
JSONObject uris = new JSONObject(json);

json is a json object not an array, that is why you are getting the error. An array will be wrapped with in [ and ], and objects within { and }.
JSONObject uris = new JSONObject (json);

Instead of JSONArray you must use JSONObject.
JSONObject uris = new JSONObject(json);

In your code just replace JSONArray to JSONobject
JSONObject uris = new JSONObject(json);

Server Response (JSON Format) to Array Conversion

I am working on an android app in which i send an http response to a server and get a response in string which is in JSON format, now on the basis of this response i need to generate a stacked column chart using AChartEngine for different equipments. The response string looks like as follows
[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":0,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":null,"EquipmentStatusDescription":null,"EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":0,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":null,"EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":561.60722222222023,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":"#008000","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":1,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.InCycle","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":134.57583333333525,"EquipmentDescription":"MTConnect","EquipmentId":5,"EquipmentName":"MTC 1","EquipmentStatusColor":"#FFFF00","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":"","EquipmentStatusTypeId":2,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.UnknownDowntime","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0}],"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":0,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":null,"EquipmentStatusDescription":null,"EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":0,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":null,"EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":[{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":495.61333333332925,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":"#008000","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":null,"EquipmentStatusTypeId":1,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeName.InCycle","EquipmentTimeZoneId":null,"EventData":null,"GeneralStatusState":0,"IsFirstRowData":false,"Percentage":0,"ReportGroupId":0,"ReportGroupName":null,"ReportGroupValue":null,"StatusAction":0,"StatusDuration":null,"TimeStamp":{"DateTime":"\/Date(-62135596800000)\/","OffsetMinutes":0},"UnknownDowntime_Duration":0,"UnknownDowntime_Percent":0},{"ChartDate":null,"CycleStatus":null,"Cycle_Duration":0,"Cycle_Percent":0,"Duration":200.56972222222623,"EquipmentDescription":null,"EquipmentId":1,"EquipmentName":"PCS Loop 1","EquipmentStatusColor":"#FFFF00","EquipmentStatusDescription":"In Cycle","EquipmentStatusId":0,"EquipmentStatusIdentifier":"","EquipmentStatusTypeId":2,"EquipmentStatusTypeName":null,"EquipmentStatusTypeName_resourceKey":"EquipmentStatusTypeNam
Now this is a response for five different equipments and how can i use this JSON string to an array so that i can extract the data of each equipment and send it to AChartEngine for drawing of chart?

You can convert the response string to JSONObject. The response you posted is JSONArray.
JSONArray jsonArray = new JSONArray(responseString);
int size = jsonArray.length();
ArrayList<JSONObject> arrayList = new ArrayList<JSONObject>();
for(int i= 0; i< size; i++) {
JSONObject jsonObject = jsonArray.optJSONObject(i);
// use this jsonObject to get the value by passing the keys.
String value = jsonObject.optString(key);
//here is your array list of jsonobjects
arrayList.add(jsonObject);
}

Use below Code for Pass JsonArray and store Value into ArrayList.
JSONArray jArray = new JSONArray(mRes);
ArrayList<String> array1 = new ArrayList<String>();
for(int i= 0; i< size; i++) {
JSONObject jObject = jArray.getJSONObject(i);
String mValue = jObject.getString("your_json_object_name");
array1.add(mValue);
}

Use Gson api, it allows you to direct mapping of json objects to java objects. check following links for further reference:
http://code.google.com/p/google-gson/
https://sites.google.com/site/gson/gson-user-guide

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

parse and get specific field from HTTP response in java - java

You are parsing json array into object. Use JSONArray instead of JSONObject JSONArray myArray = new JSONArray(response); you can get your object by index from your array.

Related

Can't parse some JSON into a JsonArray using GSON

Json object to java arraylist

Json Iterating using java

parsing URL in String from JSON

Server Response (JSON Format) to Array Conversion

Categories

Resources