I need to get specific data from this API http://countryapi.gear.host/v1/Country/getCountries?pName=Australia, convert it to String and write out on the console. I want to get data only for Australia. How can I get data in String format only for Name and Alpha2Code like this:
Australia, AU? I was trying to use EntityUtils.toString(response) but it doesn't work.
This is my code:
public class Client {
public static void main(String[] args) throws ClientProtocolException, IOException {
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://countryapi.gear.host/v1/Country/getCountries?pName=Australia");
request.addHeader("accept", "application/json");
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
InputStream stream = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
String line = reader.readLine();
System.out.println(line);
}
}
The code actually return JSON for Australia, like this:
enter image description here
Try something like this:
Gson gson = new Gson();
JsonObject result = gson.fromJson(line, JsonObject.class);
JsonArray response = result.getAsJsonArray("Response");
Country country = gson.fromJson(response, Country.class);
You can use java api for json parsing. I am just writing a sample code. YOu can explore json parsing api more on below URL:
http://www.oracle.com/technetwork/articles/java/json-1973242.html
JsonObject obj = rdr.readObject();
JsonArray results = obj.getJsonArray("data");
for (JsonObject result : results.getValuesAs(JsonObject.class)) {
System.out.print(result.getJsonObject("name").getString("name"));
System.out.print(": ");
System.out.println(result.getString("message", ""));
System.out.println("-----------");
}
Related
I am trying to do a HTTP post request to a web API and then parse the received HttpResponse and access the key value pairs in the body. My code is like this:
public class access {
// http://localhost:8080/RESTfulExample/json/product/post
public static void main(String[] args) {
HttpClient httpclient = HttpClients.createDefault();
HttpPost httppost = new HttpPost("https://XXXXXXX/RSAM_API/api/Logon");
// Request parameters and other properties.
List<NameValuePair> urlParameters = new ArrayList<NameValuePair>(2);
urlParameters.add(new BasicNameValuePair("UserId", "XXXXX"));
urlParameters.add(new BasicNameValuePair("Password", "XXXXXX"));
try {
httppost.setEntity(new UrlEncodedFormEntity(urlParameters));
//Execute and get the response.
HttpResponse response = httpclient.execute(httppost);
BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String line;
while(null !=(line=rd.readLine())){
System.out.println(line);
}
System.out.println(response);
String resp = EntityUtils.toString(response.getEntity());
JSONObject obj = new JSONObject(resp);
}
catch (Exception e){
e.printStackTrace();
}
}
}
I am trying to access the body by converting it to a JSONObject with these 2 lines of code:
String resp = EntityUtils.toString(response.getEntity());
JSONObject obj = new JSONObject(resp);
But I get an error in the second line saying:
JSONObject
(java.util.Map)
in JSONObject cannot be applied
to
(java.lang.String)
Not sure if this is the correct approach. Is there a way to do what I am trying to do?
Any help would be appreciated, Thank you.
EDIT:
So when I try to print the response body using the following lines,
String resp = EntityUtils.toString(response.getEntity());
System.out.println(resp);
I get the result: {"APIKey":"xxxxxxxxxxxxxx","StatusCode":0,"StatusMessage":"You have been successfully logged in."}
I am looking for a way to parse this result and then access each element. Is there a way to do this?
According to JsonSimple's JsonObject documentation it takes map in the constructor but not a String. So the error you are getting what it says.
You should use JSONParser to parse the string first.
Its also better to provide the encoding as part of EntityUtils.toString say UTF-8 or 16 based off your scenario.
IOUtils.toString() from Apache Commons IO would be a better choice to use too.
Try the below line to parse the JSON:
JSONParser parser = new JSONParser();
JSONObject obj = (JSONObject) parser.parse(resp);
The above lines will vaildate the JSON and through exception if the JSON is invalid.
You don't need to read the response in the extra while loop. EntityUtils.toString(response.getEntity()); will do this for you. As you read the response stream before, the stream is already closed when comming to response.getEntity().
I'm very new to RESTFull WCF Services and even newer to calling them from an Android app. Here's my WCF service:
[ServiceContract]
public interface IPeople
{
[OperationContract]
void DoWork();
[WebGet(UriTemplate = "/GetPeople",
BodyStyle = WebMessageBodyStyle.WrappedRequest,
ResponseFormat = WebMessageFormat.Json,
RequestFormat = WebMessageFormat.Json)]
[OperationContract]
string GetPeople();
}
The implementation of the interface:
public string GetPeople()
{
PeoplesEntities qe = new PeoplesEntities();
var result = from q in qe.tPeople
select q;
int count = result.Count();
int index = new Random().Next(count);
tPeople people = result.OrderBy(a=>a.ID).Skip(index).FirstOrDefault();
// result.First().ToString();
return people.FirstName + " - " + people.LastName;
}
and this is how i'm consuming it through an android service:
try {
HttpGet request = new HttpGet(SERVICE_URI + "/GetPeople");
request.setHeader("Accept", "application/json");
request.setHeader("Content-type", "application/json");
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpResponse response = httpClient.execute(request);
HttpEntity responseEntity = response.getEntity();
// Read response data into buffer
char[] buffer = new char[(int)responseEntity.getContentLength()];
InputStream stream = responseEntity.getContent();
InputStreamReader reader = new InputStreamReader(stream);
reader.read(buffer);
stream.close();
JSONArray plates = new JSONArray(new String(buffer));
return new String(buffer);
} catch (Exception e) {
e.printStackTrace();
return e.toString();
}
}
The exception I get is what is mentioned in the subject. What's strange is the value tha ti'm expecting is returned in the exception. I have no clue why it's expecting the square bracket.
FYI, most of the code i used is taken directly from online examples. Any help would be greatly appreciated. Thanks.
You're trying to create a JSONArray from a string that doesn't contain valid JSON array syntax. A JSONArray can be created from a string of the form [item1, item2, item3....] but you're just returning a single item in your string: FirstName LastName.
The line after it just returns the buffer, so the JSONArray call is pointless, anyway. You don't need the JSONArray call at all, since you're not dealing with JSON data. Just remove that line.
My request body contains JSON. i have to read that JSON save it as JSON object. And i don't have any pojo class representing the data in json. i tried this , and this and i am using com.ibm.json.java.JSONObject.i have tried this ,
BufferedReader ne = req.getReader();
StringBuffer jb = new StringBuffer();
try {
BufferedReader reader = req.getReader();
while ((line = reader.readLine()) != null)
jb.append(line);
} catch (Exception e) { /*report an error*/ }
JSONObject jsonObject = new JSONObject();
jsonObject.put("data", jb.toString());
above implementation is dumb because i am converting request header to string and adding it to jsonobject.
I think you should use public static JSONObject parse( java.lang.String str) in class JSONObject .Also there is no need to convert Reader to String as there are overloaded methods in JSONObject which take Inputstream and Reader eg public static JSONObject parse( java.io.Reader reader)
I started developing in Xamarin, and then decided that license may be a bit expensive for playing around, so I'm transferring my code to java.
I have a small chunk that performs a POST with a JSON object, and it works in Xamarin and doest work in Java.
Xamarin:
var client = new HttpClient ();
var content = new FormUrlEncodedContent(new Dictionary<string, string>() {
{"action", "getEpisodeJSON"},
{"episode", "11813"}
});
client.DefaultRequestHeaders.Referrer = new Uri(link);
var resp = client.PostAsync("http://www.ts.kg/ajax", content).Result;
var repsStr = resp.Content.ReadAsStringAsync().Result;
dynamic res = JsonConvert.DeserializeObject (repsStr);
Android:
HttpClient httpclient = new DefaultHttpClient();
// 2. make POST request to the given URL
HttpPost httpPost = new HttpPost("http://www.ts.kg/ajax");
String json = "";
// 3. build jsonObject
JSONObject jsonObject = new JSONObject();
jsonObject.accumulate("action", "getEpisodeJSON");
jsonObject.accumulate("episode", "11813");
// 4. convert JSONObject to JSON to String
json = jsonObject.toString();
// 5. set json to StringEntity
StringEntity se = new StringEntity(json);
// 6. set httpPost Entity
httpPost.setEntity(se);
// 7. Set some headers to inform server about the type of the content
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");
httpPost.addHeader("Referer", "http://www.ts.kg");
// 8. Execute POST request to the given URL
HttpResponse httpResponse = httpclient.execute(httpPost);
// 9. receive response as inputStream
InputStream inputStream = httpResponse.getEntity().getContent();
// 10. convert inputstream to string
String result;
if(inputStream != null)
result = convertInputStreamToString(inputStream);
What is a correct way to make such a POST in Android?
UPD
Current problem is that i'm getting an empty result string;
private static String convertInputStreamToString(InputStream inputStream) throws IOException{
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
I ended up catching all requests of my device via Fiddle (good tutorial is here: http://tech.vg.no/2014/06/04/how-to-monitor-http-traffic-from-your-android-phone-through-fiddler/)
The difference was in cookie, so I used and HttpContex variable as described here:
Android HttpClient Cookie
And I also had a different Content-Type, so I set this header manually as this:
httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
I am trying to read results of a JSON request into java, yet
The partial output of my JSON request looks like this :
"route_summary": {
"total_distance": 740,
"total_time": 86,
"start_point": "Marienstraße",
"end_point": "Feldbergstraße"
}
I would like to use the standard json library to extract the values in total_distance.
However I only seem to be able to get the 'route_summary' by doing this :
JSONObject json = null;
json = readJsonFromUrl(request);
json.get("route_summary");
Where
public static JSONObject readJsonFromUrl(String url) throws IOException, JSONException {
InputStream is = new URL(url).openStream();
try {
BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
String jsonText = readAll(rd);
JSONObject json = new JSONObject(jsonText);
return json;
} finally {
is.close();
}
}
What I want is get 'into' route_summary, any clue / tip would be great !
You need to get route_summary, as you already did, and from that object you need to get the total_distance. This will give you back the route_summary.total_distance.
Code sample:
JSONObject object = new JSONObject(s);
int totalDistance = object.getJSONObject("route_summary").getInt("total_distance");
I would recommend you to use GSON library. You can create class which will represent the message and then automatically map JSON to object by invoking function: gson.fromJson(message, YourMessageClass.class).getRoute_summary().
Here is the example of such approach: https://sites.google.com/site/gson/gson-user-guide/#TOC-Object-Examples