I'm trying to use a CloseableHttpAsyncClient
to read from an endpoint, marshall the string to an Object (using javax.json) then convert an array on the object into it's individual components:
CloseableHttpAsyncClient client = HttpAsyncClientBuilder.create().setDefaultCredentialsProvider(provider).build();
client.start();
Observable<ObservableHttpResponse> observable = ObservableHttp.createRequest(HttpAsyncMethods.createGet(uri), client)
.toObservable();
Observable<JsonArray> shareable = observable.flatMap(response -> response.getContent().map(bb -> {
String stringVal = new String(bb);
StringReader reader = new StringReader(stringVal);
JsonObject jobj = Json.createReader(reader).readObject();
return jobj.getJsonArray("elements");
})).share();
I need to get the Json Array, then filter the objects of the array:
Observable<JsonObject> firstStream = shareable.filter(item -> item.getString("type").equals("TYPE_1"));
Observable<JsonObject> secondStream = shareable.filter(item -> item.getString("type").equals("TYPE_2"));
Observable<JsonObject> thirdStream = shareable.filter(item -> item.getString("type").equals("TYPE_3"));
How do I convert the Observable<JsonArray>
into a ObservableJsonObject>
?
Because it's async, I can't use forEach to create some kind of array to buffer the data.
So Looking at using the CloseableHttpAsyncClient may not be the best solution for what I'm trying to achieve - I realised this morning (in the shower of all things) that I'm trying to process the data asynchronously to then make async calls.
Ideally, making the call to a CloseableHttpClient (sync) and passing the data to the Observable for filtering would be a more ideal approach (I don't need the first call to manage more than one http call).
CloseableHttpClient client = HttpClientBuilder.create().setDefaultCredentialsProvider(provider).build();
StringBuffer result = new StringBuffer();
try {
HttpGet request = new HttpGet(uri);
HttpResponse response = client.execute(request);
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
String line;
while ((line = rd.readLine()) != null) {
result.append(line);
}
} catch(ClientProtocolException cpe) { } catch(IOException ioe) { }
StringReader reader = new StringReader(result.toString());
JsonObject jobj = Json.createReader(reader).readObject();
JsonArray elements = jobj.getJsonArray("elements");
List<JsonObject> objects = elements.getValuesAs(JsonObject.class);
Observable<JsonObject> shareable = Observable.from(objects).share();
Observable<JsonObject> firstStream = shareable.filter(item -> item.getString("type").equals("TYPE_1"));
Observable<JsonObject> secondStream = shareable.filter(item -> item.getString("type").equals("TYPE_2"));
Observable<JsonObject> thirdStream = shareable.filter(item -> item.getString("type").equals("TYPE_3"));
firstStream.subscribe(record -> {
//connect to SOTS/Facebook and store the results
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Json.createWriter(baos).writeObject(record);
System.out.println(baos.toString());
});
secondStream.subscribe(record -> {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Json.createWriter(baos).writeObject(record);
System.out.println(baos.toString());
});
thirdStream.subscribe(record -> {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Json.createWriter(baos).writeObject(record);
System.out.println(baos.toString());
});
Try this code:
String myjson = "{\"elements\": [{\"text\":\"Obj1\"},{\"text\":\"Obj2\"}, {\"text\":\"Obj3\"}]}";
Observable.just(myjson)
.map(jsonStr -> new StringReader(myjson))
.map(reader -> Json.createReader(reader).readObject())
.map(jobj -> jobj.getJsonArray("elements"))
.map(elements -> elements.toArray(new JsonObject[elements.size()]))
.flatMap(jsonObjects -> Observable.from(jsonObjects))
.subscribe(
(jsonObject) -> System.out.println(jsonObject.getString("text")),
throwable -> throwable.printStackTrace(),
() -> System.out.println("On complete"));
Result:
07-22 12:19:22.362 8032-8032/com.mediamanagment.app I/System.out﹕ Obj1
07-22 12:19:22.362 8032-8032/com.mediamanagment.app I/System.out﹕ Obj2
07-22 12:19:22.362 8032-8032/com.mediamanagment.app I/System.out﹕ Obj3
NOTE:
You should use this dependency:
compile 'org.glassfish:javax.json:1.0.4'
Instead this:
compile 'javax.json:javax.json-api:1.0'
If you will use 'javax.json:javax.json-api:1.0'
you will get javax.json.JsonException: Provider org.glassfish.json.JsonProviderImpl not found
at step:
.map(reader -> Json.createReader(reader).readObject())
Thereof, please, use 'org.glassfish:javax.json:1.0.4'
UPDATE: Also, instead of
.flatMap(jsonObjects -> Observable.from(jsonObjects))
You can use flatMapIterable( )
:
.flatMapIterable(jsonObjects -> jsonObjects)
You should be able to use another flatMap()
call instead of the map()
call you are using. Then use Observable.create()
to emit JsonObject
s
Observable<JsonObject> shareable =
observable
.flatMap(response -> response.getContent()
.flatMap(bb -> {
String stringVal = new String(bb);
StringReader reader = new StringReader(stringVal);
JsonObject jobj = Json.createReader(reader).readObject();
JsonArray elements = jobj.getJsonArray("elements");
return Observable.create(subscriber -> {
for (int i = 0; i < elements.length(); i++) {
subscriber.onNext(elements.getJSONObject(i));
}
subscriber.onCompleted();
});
}))
.share();
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