retrofit gives java.lang.VerifyError

Question

I am trying to get data from a site using Retrofit. I have followed the examples online http://kdubblabs.com/java/retrofit-by-square/retrofit-simple-get/ and http://corner.squareup.com/2013/05/retrofit-one-dot-oh.html. I am pasting my code below -

public class MainActivity extends ActionBarActivity {

    public interface CatAPI{
        @GET("/apj/category.php")
        public String subCat();
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        public PlaceholderFragment() {
        }

        @SuppressWarnings("deprecation")
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            Builder b=new RestAdapter.Builder();
            Builder s=b.setServer("http://kurdshopping.net/");
            RestAdapter adapter=s.build();
            CatAPI api=adapter.create(CatAPI.class);
            String response=api.subCat();
            Log.i("Subcat", response);
            return rootView;
        }
    }

}

Please tell me what I am doing wrong. The logcat showed the following error -

05-06 17:23:41.037: E/AndroidRuntime(3365): FATAL EXCEPTION: main
05-06 17:23:41.037: E/AndroidRuntime(3365): Process: com.example.retrofitdemo, PID: 3365
05-06 17:23:41.037: E/AndroidRuntime(3365): java.lang.VerifyError: retrofit/converter/GsonConverter
05-06 17:23:41.037: E/AndroidRuntime(3365):     at retrofit.Platform$Android.defaultConverter(Platform.java:117)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at retrofit.RestAdapter$Builder.ensureSaneDefaults(RestAdapter.java:714)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at retrofit.RestAdapter$Builder.build(RestAdapter.java:707)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at com.example.retrofitdemo.MainActivity$PlaceholderFragment.onCreateView(MainActivity.java:82)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:938)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1115)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1478)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:570)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.Activity.performStart(Activity.java:5241)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2168)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.os.Handler.dispatchMessage(Handler.java:102)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.os.Looper.loop(Looper.java:136)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at android.app.ActivityThread.main(ActivityThread.java:5017)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at java.lang.reflect.Method.invokeNative(Native Method)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at java.lang.reflect.Method.invoke(Method.java:515)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-06 17:23:41.037: E/AndroidRuntime(3365):     at dalvik.system.NativeStart.main(Native Method)

It would be nice if somebody could help me get started with retrofit. Thanks in advance for the help.

Answer 1

Looks like you are missing Gson, maybe? Try adding the Gson .jar to your lib folder.