I am trying to get a specific Item from an API in my android application. Here is the JSON response of the api:
{
"response": {
"items": [
{
"episode_id": 9599548,
"type": "RECORDED",
"title": "Adabule muferad 100916",
"duration": 3165940,
"explicit": false,
"show_id": 1392538,
"author_id": 7725967,
"site_url": "https://www.spreaker.com/episode/9599548",
"image_url": "https://d1bm3dmew779uf.cloudfront.net/large/f390b915e356de35055d971be5110dcb.jpg",
"image_original_url": "https://d3wo5wojvuv7l.cloudfront.net/images.spreaker.com/original/f390b915e356de35055d971be5110dcb.jpg",
"published_at": "2016-10-09 11:01:48",
"download_enabled": true,
"waveform_url": "https://d3770qakewhkht.cloudfront.net/episode_9599548.gz.json?v=qB6pQ6"
}
],
"next_url": "https://api.spreaker.com/v2/users/7725967/episodes?filter=listenable&last_id=9599548&limit=1"
}
}
I have three Java classes Items, Response and RadioProgramInfo. Here are their codes respectively:
Items.java
public class Items
{
public String duration;
public String title;
public String download_enabled;
public String image_original_url;
public String image_url;
public String explicit;
public String episode_id;
public String author_id;
public String show_id;
public String type;
public String waveform_url;
public String published_at;
public String site_url;
public String getDuration ()
{
return duration;
}
public void setDuration (String duration)
{
this.duration = duration;
}
public String getTitle ()
{
return title;
}
public void setTitle (String title)
{
this.title = title;
}
public String getDownload_enabled ()
{
return download_enabled;
}
public void setDownload_enabled (String download_enabled)
{
this.download_enabled = download_enabled;
}
public String getImage_original_url ()
{
return image_original_url;
}
public void setImage_original_url (String image_original_url)
{
this.image_original_url = image_original_url;
}
public String getImage_url ()
{
return image_url;
}
public void setImage_url (String image_url)
{
this.image_url = image_url;
}
public String getExplicit ()
{
return explicit;
}
public void setExplicit (String explicit)
{
this.explicit = explicit;
}
public String getEpisode_id ()
{
return episode_id;
}
public void setEpisode_id (String episode_id)
{
this.episode_id = episode_id;
}
public String getAuthor_id ()
{
return author_id;
}
public void setAuthor_id (String author_id)
{
this.author_id = author_id;
}
public String getShow_id ()
{
return show_id;
}
public void setShow_id (String show_id)
{
this.show_id = show_id;
}
public String getType ()
{
return type;
}
public void setType (String type)
{
this.type = type;
}
public String getWaveform_url ()
{
return waveform_url;
}
public void setWaveform_url (String waveform_url)
{
this.waveform_url = waveform_url;
}
public String getPublished_at ()
{
return published_at;
}
public void setPublished_at (String published_at)
{
this.published_at = published_at;
}
public String getSite_url ()
{
return site_url;
}
public void setSite_url (String site_url)
{
this.site_url = site_url;
}
@Override
public String toString()
{
return "ClassPojo [duration = "+duration+", title = "+title+", download_enabled = "+download_enabled+", image_original_url = "+image_original_url+", image_url = "+image_url+", explicit = "+explicit+", episode_id = "+episode_id+", author_id = "+author_id+", show_id = "+show_id+", type = "+type+", waveform_url = "+waveform_url+", published_at = "+published_at+", site_url = "+site_url+"]";
}
}
Response.java
public class Response
{
private Items[] items;
private String next_url;
public Items[] getItems ()
{
return items;
}
public void setItems (Items[] items)
{
this.items = items;
}
public String getNext_url ()
{
return next_url;
}
public void setNext_url (String next_url)
{
this.next_url = next_url;
}
@Override
public String toString()
{
return "ClassPojo [items = "+items+", next_url = "+next_url+"]";
}
}
RadioProgramInfo.java
public class RadioProgramInfo
{
private Response response;
public Response getResponse ()
{
return response;
}
public void setResponse (Response response)
{
this.response = response;
}
@Override
public String toString()
{
return "ClassPojo [response = "+response+"]";
}
}
I am trying to access a specific Item called "site_url" which is located in Items.java
The code in my main class to try to access site_url is this:
Items url2 = new Items();
String streamURL = String.valueOf(url2)+"/shoutcast?force_http=true";
// new HttpRequestTask().execute();
// return true;
String url = "http://api.spreaker.com/listen/episode/9451446/shoutcast?force_http=true";
//String url2 = Items.class.getName(site_url);
public MainActivity() {
}
//System.out.println(streamURL);
public class HttpRequestTask extends AsyncTask<Void, Void, Items> {
protected Items doInBackground(Void... params) {
try {
final String url = String.valueOf(streamURL);
RestTemplate restTemplate = new RestTemplate();
//restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
Items streamlink = restTemplate.getForObject(url, Items.class);
return streamlink;
}
catch (Exception e) {
Log.e("MainActivity", e.getMessage(), e);
}
return url2;
}
}
When I run my program (a media player app): It tells me that the url is null in value (I debug mode on the program as it executes).
How do I correctly access the item in the JSON response I am after? I am really stuck on this one.
---UPDATE----- Here is the response from the console:
10-09 15:25:39.522 2586-2647/software.blackstone.com.salafimasjidradioseries E/MainActivity: 'messageConverters' must not be empty
java.lang.IllegalArgumentException: 'messageConverters' must not be empty
at org.springframework.util.Assert.notEmpty(Assert.java:269)
at org.springframework.web.client.HttpMessageConverterExtractor.<init>(HttpMessageConverterExtractor.java:53)
at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:235)
at software.blackstone.com.salafimasjidradioseries.MainActivity$HttpRequestTask.doInBackground(MainActivity.java:46)
at software.blackstone.com.salafimasjidradioseries.MainActivity$HttpRequestTask.doInBackground(MainActivity.java:39)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
.... and the complete MainActivity Code is this:
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;
import org.springframework.web.client.RestTemplate;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
static MediaPlayer mPlayer;
ImageButton buttonPlay;
ImageButton buttonStop;
Items url2 = new Items();
String streamURL = String.valueOf(url2)+"/shoutcast?force_http=true";
// new HttpRequestTask().execute();
// return true;
String url = "http://api.spreaker.com/listen/episode/9451446/shoutcast?force_http=true";
//String url2 = Items.class.getName(site_url);
public MainActivity() {
}
//System.out.println(streamURL);
public class HttpRequestTask extends AsyncTask<Void, Void, Items> {
protected Items doInBackground(Void... params) {
try {
final String url = String.valueOf(streamURL);
RestTemplate restTemplate = new RestTemplate();
//restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
Items streamlink = restTemplate.getForObject(url, Items.class);
return streamlink;
}
catch (Exception e) {
Log.e("MainActivity", e.getMessage(), e);
}
return url2;
}
}
@Override
protected void onStart() {
super.onStart();
new HttpRequestTask().execute();
}
i admittedly don't have any experience using Spring libraries for mobile development. there are, however, several other popular libraries at your disposal that are typically used to accomplish your goal.
below is an example i whipped using your DTO classes. i added these dependencies via my app's build.gradle:
compile 'com.squareup.okhttp:okhttp:2.7.5'
compile 'com.google.code.gson:gson:2.4'
the code should be pretty self-explanatory. i've just plugged in the bits to do my HTTP GET and marshal the data into the DTO within the AsyncTask.
public class MainActivity extends AppCompatActivity {
private MediaPlayer mPlayer = new MediaPlayer();
private OkHttpClient client = new OkHttpClient();
private Gson gson = new Gson();
public class HttpRequestTask extends AsyncTask<Void,Void,Items[]> {
protected Items[] doInBackground(Void... params) {
final Request request = new Request.Builder()
.url("https://api.myjson.com/bins/1z98u")
.build();
Items[] items = null;
try {
final com.squareup.okhttp.Response response = client.newCall(request).execute();
if(response.isSuccessful()) {
final RadioProgramInfo radioProgramInfo = gson.fromJson(response.body().charStream(), RadioProgramInfo.class);
items = radioProgramInfo.getResponse().getItems();
} else {
throw new RuntimeException("ooops!");
}
} catch (Throwable t) {
Log.e("MainActivity", t.getMessage(), t);
}
return items;
}
@Override
protected void onPostExecute(Items[] items) {
try {
mPlayer.setDataSource(items[0].getSite_url());
mPlayer.prepareAsync();
} catch(IOException e) {
e.printStackTrace();
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
@Override
public void onPrepared(MediaPlayer mp) {
mp.start();
}
});
new HttpRequestTask().execute();
}
}
hope that helps!