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Chris Biscardi

Android RoboSpice with GoogleHttpClient

In this post we will examine an example app in which we make a RoboSpice request using GoogleHttpClient.

The github repo is here.

Dependencies

First, we need to grab the RoboSpice dependency JARs from the repository repo.

bash
git clone https://github.com/octo-online/robospice/tree/repository

Inside of 1.4.11/robospice-google-http-client are the JARs we need to include in the project. If you are using Eclipse copy the JARs into your libs/ folder and add them to the build path in Project -> Properties -> Libraries by clicking Add JARs. You may also need to click the Order and Export tab, check their boxes and move the included JARs to the top.

We will also need one JAR from the Google-Http-Lib source. It is google-http-client-1.17.0. Again, if using Eclipse, add it to your project in the same way.

Classes

We are going to create a few files:

BaseSpiceActivity

java
import com.octo.android.robospice.JacksonGoogleHttpClientSpiceService;
import com.octo.android.robospice.SpiceManager;


public class BaseSpiceActivity extends Activity {
    private SpiceManager spiceManager = new SpiceManager(JacksonGoogleHttpClientSpiceService.class);


    @Override
    protected void onStart() {
        spiceManager.start(this);
        super.onStart();
    }


    @Override
    protected void onStop() {
        spiceManager.shouldStop();
        super.onStop();
    }


    protected SpiceManager getSpiceManager() {
        return spiceManager;
    }


}

The big thing we’re doing in this file is creating an instance of SpiceManager that will be accessible in the activities that inherit from this base class (like our MainActivity.java will).

We then start spiceManager in onStart() and stop it in onStop. This will ensure that our activities have a SpiceManager accessible when they start and clean up after themselves when they stop.

The final piece is a getter function (getSpiceManager()) so that we have easy access to the spiceManager in our activities.

Reddit*.java

We will be getting our data from Reddit, so we first need to examine the responses we’re going to get. I’ve chosen a subreddit where all the posts are very similar (/r/Riak). Here is a sample API response:

javascript
{
   "kind":"Listing",
   "data":{
      "modhash":"3mxugaulcd1f8b500be09",
      "children":[
         {
            "kind":"t3",
            "data":{
               "domain":"github.com",
               "banned_by":null,
               "media_embed":{


               },
               "subreddit":"Riak",
               "selftext_html":null,
               "selftext":"",
               "likes":null,
               "secure_media":null,
               "link_flair_text":null,
               "id":"19v60r",
               "secure_media_embed":{


               },
               "clicked":false,
               "stickied":false,
               "author":"BonzoESC",
               "media":null,
               "score":1,
               "approved_by":null,
               "over_18":false,
               "hidden":false,
               "thumbnail":"",
               "subreddit_id":"t5_2s3vw",
               "edited":false,
               "link_flair_css_class":null,
               "author_flair_css_class":null,
               "downs":0,
               "saved":false,
               "is_self":false,
               "permalink":"/r/Riak..riak/",
               "name":"t3_19v60r",
               "created":1362687827.0,
               "url":"https://github.com/basho/riak_dt",
               "author_flair_text":null,
               "title":"riak_dt: CRDT for Riak",
               "created_utc":1362687827.0,
               "ups":1,
               "num_comments":0,
               "visited":false,
               "num_reports":null,
               "distinguished":null
            }
         }
      ],
      "after":null,
      "before":null
   }
}

We will create a few classes to model the data. The first being Reddit.java.

In Reddit.java we include the keys kind and data using @Key declarations. Then we declare their types.

java
package com.christopherbiscardi.robospicetest;


import com.google.api.client.util.Key;


public class Reddit {
    @Key
    private String kind;
    @Key
    private RedditData data;


    public Reddit() {
    }

Then define some basic getters for when we are dealing with our request’s response.

java
public String getKind() {
        return this.kind;
    }


    public RedditData getData() {
        return this.data;
    }

and override some utility functions:

java
@Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ( kind == null ? 0 : kind.hashCode() ) + ( data == null ? 0 : data.hashCode() );
        return result;
    }


    @Override
    public boolean equals( Object obj ) {
        if ( this == obj ) {
            return true;
        }
        if ( obj == null ) {
            return false;
        }
        if ( getClass() != obj.getClass() ) {
            return false;
        }
        Reddit other = (Reddit) obj;
        if ( kind == null ) {
            if ( other.kind != null ) {
                return false;
            }
        } else if ( !kind.equals( other.kind ) ) {
            return false;
        }
        return true;
    }


    @Override
    public String toString() {
        return "Reddit [kind=" + kind + " " + data + "]";
    }
}

The model files will all follow this same format: @Key definitions, getters, utilities.

Our final model (RedditListing.java) is where we are getting the content we care about. We don’t have to include @Key for every key in our JSON response, so we’ll just grab the ones we care about:

java
@Key
    private String domain;
    @Key
    private String author;
    @Key
    private String permalink;
    @Key
    private String title;

SpiceRequestReddit.java

To finish off our classes, we’ll create a SpiceRequest that takes a string (our subreddit) and returns a Reddit.

java
package com.christopherbiscardi.robospicetest;


import java.io.IOException;


import roboguice.util.temp.Ln;


import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.json.jackson.JacksonFactory;
import com.octo.android.robospice.request.googlehttpclient.GoogleHttpClientSpiceRequest;


public class SpiceRequestReddit extends GoogleHttpClientSpiceRequest<reddit> {
    private String baseUrl;


    public SpiceRequestReddit( String subreddit ) {
        super( Reddit.class );
        this.baseUrl = String.format( "http://www.reddit.com/r/%s.json", subreddit );
    }


    @Override
    public Reddit loadDataFromNetwork() throws IOException {
        Ln.d( "Call web service " + baseUrl );
        HttpRequest request = getHttpRequestFactory()//
                .buildGetRequest( new GenericUrl( baseUrl ) );
        request.setParser( new JacksonFactory().createJsonObjectParser() );
        return request.execute().parseAs( getResultType() );
    }
}</reddit>

Calling the API

In MainActivity.java we need to add some code to execute the request:

We need to extend our MainActivity from BaseSpiceActivity

java
public class MainActivity extends BaseSpiceActivity {

Add a new SpiceRequestReddit

java
private SpiceRequestReddit spiceRequestReddit;

Instantiate it with the Riak subreddit;

java
spiceRequestReddit = new SpiceRequestReddit( "Riak" );

and implement our ResultHandler class:

java
public final class RedditSpiceRequestListener implements RequestListener {


        @Override
        public void onRequestFailure( SpiceException spiceException ) {
            Toast.makeText( MainActivity.this, "failure", Toast.LENGTH_SHORT ).show();
        }


        @Override
        public void onRequestSuccess( final Reddit result ) {
            Toast.makeText( MainActivity.this, "success", Toast.LENGTH_SHORT ).show();
            Log.e("TEST",result.getData().toString());
            Log.e("TEST",result.getData().getChildren().get(0).getData().getTitle());
        }
    }

We’ve just implemented a simple log to view the data, but we could have added it to an ArrayAdapter and displayed it in a ListView.

Finally, we override the onStart() method to actually make the request.

java
@Override
    protected void onStart() {
        super.onStart();


        setProgressBarIndeterminate( false );
        setProgressBarVisibility( true );


        getSpiceManager().execute( spiceRequestReddit, "json", DurationInMillis.ONE_MINUTE, new RedditSpiceRequestListener() );
    }

AndroidManifest.xml

Now that’s all the code we need to write, but we still need to register our service and permissions in AndroidManifest.xml. Notice we’ve added three uses-permission nodes and a service node.

xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.christopherbiscardi.robospicetest"
    android:versionCode="1"
    android:versionName="1.0" >


    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />


    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />


    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.christopherbiscardi.robospicetest.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />


                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>


        <service
            android:name="com.octo.android.robospice.JacksonGoogleHttpClientSpiceService"
            android:exported="false" />
    </application>


</manifest>

Fin

Now we can run the app and see the result (success or failure) pop up as a Toast as well as viewing the actual data in LogCat.

Check out the github repository here