Strange problems with the Spring RestTemplate in Android application - java

I began to use RESTful api of the Spring Framework in my android client application. But I have encountered with problems when I tried to execute HTTP request via postForObject/postForEntity methods. Here is my code:
public String _URL = "https://someservice/mobile/login";
public void BeginAuthorization(View view)
{
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> _entity = new HttpEntity<String>(requestHeaders);
RestTemplate templ = new RestTemplate();
templ.setRequestFactory(new HttpComponentsClientHttpRequestFactory());
templ.getMessageConverters().add(new MappingJacksonHttpMessageConverter());
ResponseEntity<String> _response = templ.postForEntity(_URL,_entity,String.class); //HERE APP CRASHES
String _body = _response.getBody();
So the question what am I doing wrong? How to fix this? May there is other way to do it?I really need a help. Thanks in advance!

I think you are targeting your app Android 4.0-4.2. Then you must perform all your operations in the background, not main (UI) thread. You are performing an authorization process, as I see. It's a short operation, so it's better for you to use AsyncTask for this. Here is howto for this on androidDevelopers:
http://developer.android.com/reference/android/os/AsyncTask.html
You should override doInBackground(Params...) in such a way:
class LoginTask extends AsyncTask<String,Void,Void>
{
#Override
protected Void doInBackground(String... params) {
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> _entity = new HttpEntity<String>(requestHeaders);
RestTemplate templ = new RestTemplate();
templ.setRequestFactory(new HttpComponentsClientHttpRequestFactory());
templ.getMessageConverters().add(new MappingJacksonHttpMessageConverter());
ResponseEntity<String> _response = templ.postForEntity(params[0],_entity,null) //null here in order there wasn't http converter errors because response type String and [text/html] for JSON are not compatible;
String _body = _response.getBody();
return null;
}
}
And then call it in your BeginAuthorization(View view):
new LoginTask().execute(URL);
P.S. Also if you write Java please use correct naming conventions. Instead of this _response please write response.

From the documentation:
NetworkOnMainThreadException
The exception that is thrown when an application attempts to perform a
networking operation on its main thread.
You should make a thread and do the networking from there. This may be what you are looking for.

from android>= 4.0 network calls must go through asynctack

Related

How to make a rest api call in java and map the response object?

I'm currently developing my first java program who'll make a call to a rest api(jira rest api, to be more especific).
So, if i go to my browser and type the url =
"http://my-jira-domain/rest/api/latest/search?jql=assignee=currentuser()&fields=worklog"
I get a response(json) with all the worklogs of the current user.
But my problem is, how i do my java program to do this ?
Like,connect to this url, get the response and store it in a object ?
I use spring, with someone know how to this with it.
Thx in advance guys.
Im adding, my code here:
RestTemplate restTemplate = new RestTemplate();
String url;
url = http://my-jira-domain/rest/api/latest/search/jql=assignee=currentuser()&fields=worklog
jiraResponse = restTemplate.getForObject(url,JiraWorklogResponse.class);
JiraWorkLogResponse is a simple class with some attributes only.
Edit,
My entire class:
#Controller
#RequestMapping("/jira/worklogs")
public class JiraWorkLog {
private static final Logger logger = Logger.getLogger(JiraWorkLog.class.getName() );
#RequestMapping(path = "/get", method = RequestMethod.GET, produces = "application/json")
public ResponseEntity getWorkLog() {
RestTemplate restTemplate = new RestTemplate();
String url;
JiraProperties jiraProperties = null;
url = "http://my-jira-domain/rest/api/latest/search?jql=assignee=currentuser()&fields=worklog";
ResponseEntity<JiraWorklogResponse> jiraResponse;
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders = this.createHeaders();
try {
jiraResponse = restTemplate.exchange(url, HttpMethod.GET, new HttpEntity<Object>(httpHeaders),JiraWorklogResponse.class);
}catch (Exception e){
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(e.getMessage());
}
return ResponseEntity.status(HttpStatus.OK).body(jiraResponse);
}
private HttpHeaders createHeaders(){
HttpHeaders headers = new HttpHeaders(){
{
set("Authorization", "Basic something");
}
};
return headers;
}
This code is returning :
org.springframework.http.converter.HttpMessageNotWritableException
Anyone knows why ?
All you need is http client. It could be for example RestTemplate (related to spring, easy client) or more advanced and a little more readable for me Retrofit (or your favorite client).
With this client you can execute requests like this to obtain JSON:
RestTemplate coolRestTemplate = new RestTemplate();
String url = "http://host/user/";
ResponseEntity<String> response
= restTemplate.getForEntity(userResourceUrl + "/userId", String.class);
Generally recommened way to map beetwen JSON and objects/collections in Java is Jackson/Gson libraries. Instead them for quickly check you can:
Define POJO object:
public class User implements Serializable {
private String name;
private String surname;
// standard getters and setters
}
Use getForObject() method of RestTemplate.
User user = restTemplate.getForObject(userResourceUrl + "/userId", User.class);
To get basic knowledge about working with RestTemplate and Jackson , I recommend you, really great articles from baeldung:
http://www.baeldung.com/rest-template
http://www.baeldung.com/jackson-object-mapper-tutorial
Since you are using Spring you can take a look at RestTemplate of spring-web project.
A simple rest call using the RestTemplate can be:
RestTemplate restTemplate = new RestTemplate();
String fooResourceUrl = "http://localhost:8080/spring-rest/foos";
ResponseEntity<String> response = restTemplate.getForEntity(fooResourceUrl + "/1", String.class);
assertThat(response.getStatusCode(), equalTo(HttpStatus.OK));
The issue could be because of the serialization. Define a proper Model with fields coming to the response. That should solve your problem.
May not be a better option for a newbie, but I felt spring-cloud-feign has helped me to keep the code clean.
Basically, you will be having an interface for invoking the JIRA api.
#FeignClient("http://my-jira-domain/")
public interface JiraClient {
#RequestMapping(value = "rest/api/latest/search?jql=assignee=currentuser()&fields=", method = GET)
JiraWorklogResponse search();
}
And in your controller, you just have to inject the JiraClient and invoke the method
jiraClient.search();
And it also provides easy way to pass the headers.
i'm back and with a solution (:
#Controller
#RequestMapping("/jira/worklogs")
public class JiraWorkLog {
private static final Logger logger = Logger.getLogger(JiraWorkLog.class.getName() );
#RequestMapping(path = "/get", method = RequestMethod.GET, produces = "application/json")
public ResponseEntity<JiraWorklogIssue> getWorkLog(#RequestParam(name = "username") String username) {
String theUrl = "http://my-jira-domain/rest/api/latest/search?jql=assignee="+username+"&fields=worklog";
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<JiraWorklogIssue> response = null;
try {
HttpHeaders headers = createHttpHeaders();
HttpEntity<String> entity = new HttpEntity<>("parameters", headers);
response = restTemplate.exchange(theUrl, HttpMethod.GET, entity, JiraWorklogIssue.class);
System.out.println("Result - status ("+ response.getStatusCode() + ") has body: " + response.hasBody());
}
catch (Exception eek) {
System.out.println("** Exception: "+ eek.getMessage());
}
return response;
}
private HttpHeaders createHttpHeaders()
{
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
headers.add("Authorization", "Basic encoded64 username:password");
return headers;
}
}
The code above works, but can someone explain to me these two lines ?
HttpEntity<String> entity = new HttpEntity<>("parameters", headers);
response = restTemplate.exchange(theUrl, HttpMethod.GET, entity, JiraWorklogIssue.class);
And, this is a good code ?
thx (:

How to consume a HTTPS GET service with Spring Boot

I am trying to consume the following HTTPS endpoints from Yahoo Weather Service:
Yahoo Weather Service API
I am doing some special query according to the API to get the current weather at some parametrized location.
#Service("weatherConditionService")
public class WeatherConditionServiceImpl implements WeatherConditionService {
private static final String URL = "http://query.yahooapis.com/v1/public/yql";
public WeatherCondition getCurrentWeatherConditionsFor(Location location) {
RestTemplate restTemplate = new RestTemplate();
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append(URL);
stringBuilder.append("?q=select%20item.condition%20from%20weather.forecast%20where%20woeid%20in%20(select%20woeid%20from%20geo.places(1)%20where%20text%3D%22");
// TODO: Validate YQL query injection
stringBuilder.append(location.getName());
stringBuilder.append("%22)&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys");
WeatherQuery weatherQuery = restTemplate.getForObject(stringBuilder.toString(), WeatherQuery.class);
// TODO: Test Json mapping response
Condition condition = weatherQuery.getQuery().getResults().getChannel().getItem().getCondition();
return new WeatherCondition(condition.getDate(), Integer.parseInt(condition.getTemp()), condition.getText());
}
Location is a class that provides the attribute "name" that is a String description of the location, such as "New York" or "Manila".
Condition an other classes just map the returning object.
When executing I get the following HTTP response:
org.springframework.web.client.HttpClientErrorException: 403 Forbidden
So this means I am not authorized to access the resource from what I understand.
The URL works great if I just copy & paste it in a web browser:
Yahoo Weather Query
I think that mapping is not a problem since I am not getting "400" (Bad Request) but "403" (Forbidden)
There must be some error on the way I use the RestTemplate object. I am researching but I can't find an answer.
The docs say you need an api key. But when I make a call like this:
fetch('https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20weather.forecast%20where%20woeid%20in%20(select%20woeid%20from%20geo.places(1)%20where%20text%3D%22nome%2C%20ak%22)&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys')
.then(resp=> resp.json())
.then((res)=>console.log(res.query.results))
https://repl.it/NeoM
It works fine without one. Perhaps you've been blackisted for hitting the api too often.
Your code seems fine.
I finally found the answer. It finally WAS a Bad Request because I needed to pass the parameters differently (not as part of the URL).
I found the answer here. Here goes the code for my particular Yahoo Weather API call return a String (I still will have to do some work to use the mapping).
private static final String URL = "http://query.yahooapis.com/v1/public/yql";
public String callYahooWeatherApi() {
RestTemplate restTemplate = new RestTemplate();
HttpHeaders headers = new HttpHeaders();
headers.set("Accept", MediaType.APPLICATION_JSON_VALUE);
UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(URL)
.queryParam("q", "select wind from weather.forecast where woeid=2460286")
.queryParam("format", "json");
HttpEntity<?> entity = new HttpEntity<>(headers);
HttpEntity<String> response = restTemplate.exchange(
builder.build().encode().toUri(),
HttpMethod.GET,
entity,
String.class);
return response.getBody();
}

Spring data rest application backend notify frontend

Hi I would like to my backend (spring-data-rest) application to generate some sample data and notify frontend. However the repository event handler is REST only so I tried to write a restTemplate but failed.
#Scheduled(fixedRate = 5000)
public void addCounter() throws Exception {
String url = String.format("http://localhost:%d/%s/counters", 8080, api);
Counter counterExpected = new Counter('xxx', random.nextInt(100));
ObjectMapper mapper = new ObjectMapper();
String jsonString = mapper.writeValueAsString(counterExpected);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> entity = new HttpEntity<String>(jsonString, headers);
restTemplate.postForObject(url, entity, String.class);
}
Error:
Description:
Field restTemplate in ScheduledTask required a bean of type 'org.springframework.boot.test.web.client.TestRestTemplate' that could not be found.
Action:
Consider defining a bean of type 'org.springframework.boot.test.web.client.TestRestTemplate' in your configuration.
This error makes sense because I am using TestTestTemplate in my runtime application instead of test scope.
My questions are:
Is it possible to change the addCounter() method to something simpler just like:
counterRepository.save(newCounter);
/* Raise AfterCreate event */
If yes, then how?
If not then is there any other way to do a HTTP post instead of using restTemplate?
My bad. I should be using
import org.springframework.web.client.RestTemplate;
instead of
import org.springframework.boot.test.web.client.TestRestTemplate;

Trying to use bing translator API with Robospice in Android

I need to implement robospice for doing the networking part in my Translator app. I previously used async task class and it was working fine, but now i want to improve my application with implementing robospice. I'am trying to execute the following code but it doesn't't throw any exception it just never executes....
#Override
public TranslatedText loadDataFromNetwork() throws Exception {
String jsonString = getJsonString();
String headerValue = getHeaderValue(jsonString);
String text = pair.getWordPairs().getWordFrom();
String languageFrom = pair.getLanguagePairs().getLanguageFrom().getCode();
String languageTo = pair.getLanguagePairs().getLangougateTo().getCode();
String uri = String
.format("http://api.microsofttranslator.com/v2/Http.svc/Translate?text=%s&from=%s&to=%s&contentType=text/html",
URLEncoder.encode(text, "UTF-8"),
URLEncoder.encode(languageFrom, "UTF-8"),
URLEncoder.encode(languageTo, "UTF-8"));
HttpHeaders headers = new HttpHeaders();
headers.set("Authorization", headerValue);
// Create a new RestTemplate instance
RestTemplate restTemplate = new RestTemplate();
// Add the Simple XML message converter
getRestTemplate().getMessageConverters().add(new SimpleXmlHttpMessageConverter());
//set the headerValue in the Entity
org.springframework.http.HttpEntity<?> request = new org.springframework.http.HttpEntity<Object>(headerValue);
// Make the HTTP GET request, marshaling the response from XML to an
// EventList
Log.v("request","Making request!");
//This line never finish execuitng, doesen't throw exception or anything in logCat
ResponseEntity<Object> responseEntity = getRestTemplate().exchange(uri, HttpMethod.GET, request, null);
Log.v("request", responseEntity.getBody().toString());
Log.d("Load Data From Network", request.getBody().toString());
return null;
}
The last thing it shows in log cat is Request First!! And nothing after that. It never even gets to The Request Listener onRequestFailure.
Can any 1 tell me what i do wrong ?
This is what look weird to me in your code:
ResponseEntity<Object> and null as 4th parameter of the exchange method are not correct. You need to provide a type which represents the response you get from the server.
The object returned by loadDataFromNetwork() is what you will get in the onRequestSuccess() method. Returning null is not a good idea, in my opinion.
I fixed the problem. So if you need to handle stream you will have to provide the following code
ResponseEntity<byte[]> responseEntity = getRestTemplate().exchange(uri, HttpMethod.GET, request, byte[]);

Calling an RESTFul using Spring-Android

Here is my Strifified json,
{
"Request":{
"Object1":{
"Key1":"Value1"
},
"Object2":{
"Key2":"Value2"
}
},
"Object3":{
"Key3":"Value3"
}
}
I am forming this using Gson. String Stringifiedjson = new Gson().toJson(user);
Here is what i am trying to achive.
RestTemplate rest = new RestTemplate();
String url = "";
String event = rest.getForObject(url, Stringifiedjson);
How would i send to my REST Service and get back my result in onEventHandler or onErrorHandler. I am basically from JavaScript background.
Why does the method getForObject does not accept String, String as params.
Update:
AuthenticateUser user = new AuthenticateUser(credential, Header);
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setContentType(new MediaType("application","json"));
//HttpEntity<AuthenticateUser> requestEntity = new HttpEntity<AuthenticateUser>(user, requestHeaders);
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new MappingJacksonHttpMessageConverter());
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
String url = "url";
String result = restTemplate.postForObject(url, AuthenticateUser.class, String.class);
Attached is the pastie of what exception i am getting.
http://pastie.org/private/efyfvvbxyxdsvm3lvv7q
About the second question: I just found this example (you could take a look at the entire doc ;) )
2.7.1 Basic Usage Example
The following example shows a query to google for the search term "SpringSource".
String url = "https://ajax.googleapis.com/ajax/services/search/web?v=1.0&q={query}";
// Create a new RestTemplate instance
RestTemplate restTemplate = new RestTemplate();
// Add the String message converter
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());
// Make the HTTP GET request, marshaling the response to a String
String result = restTemplate.getForObject(url, String.class, "SpringSource");
getForObject
public <T> T getForObject(URI url,
Class<T> responseType)
throws RestClientException
Description copied from interface: RestOperations
Retrieve a representation by doing a GET on the URL . The response (if any) is converted and returned.
Specified by:
getForObject in interface RestOperations
Parameters:
url - the URL
responseType - the type of the return value
Returns:
the converted object
Throws:
RestClientException
The exception in your stacktrace could be related to the same issue of this post. The problem occurs when your app tries to make a connection in the main thread.
10-23 15:46:10.106: E/AndroidRuntime(1038): FATAL EXCEPTION: main
10-23 15:46:10.106: E/AndroidRuntime(1038): android.os.NetworkOnMainThreadException
The NetworkOnMainThreadException is thrown when you execute any network operation in your application main ui thread (see also Keeping Your App Responsive. This is not allowed. You'll have to use a background thread for network operation, see Worker threads on http://developer.android.com/guide/components/processes-and-threads.html

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