Webservice almost 100% (Rest/json)

Question

I have a problem that I can not solve T_T, after many searches I created a web service (test), to be consumed by an android application.

The only function of it is to return a String, but I don’t know why it doesn’t work, because the String even appears in the logcat, I did all the way, but no arrow in the TextView.

If you can give me a hand, I’ll be very grateful, here comes the code:

Webservice:

package com.rodasdo;

import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.Produces;


@Path("/oi")
public class Trator {
    @GET
    @Produces("application/json")
    public String returnTitle(){
        return "Tripa de Galinha azeda";
    }
}

Mainactivity Android:

package com.example.consultasitio;

import com.example.consultasitio.ConsultaSituacao.ConstultaSituacaoSitioListener;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity implements ConstultaSituacaoSitioListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        new ConsultaSituacao(this).execute();

    }

    @Override
    public void onConsultaConcluida(String situacaositio) {
        // TODO Auto-generated method stub

        TextView text = (TextView) findViewById(R.id.what);
        text.setText(situacaositio);

    }
}

Class connecting with Ws:

package com.example.consultasitio;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;


public class ConsultaSituacao extends AsyncTask<Void, Void, String> {

    private ConstultaSituacaoSitioListener listener;

    private static final String URL_STRING = "http://192.168.1.9:8080/Servidorincompleto/oi";



    public ConsultaSituacao (ConstultaSituacaoSitioListener listener) {
        this.listener=listener;
    }

    @Override
    protected String doInBackground(Void... params) {


        try {
            String resultado = consultaServidor();

            return interpretaresultado(resultado);


        } catch (IOException e) {
            e.printStackTrace();
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            return null;
        }
        return null;
    }

    private String interpretaresultado(String resultado) throws JSONException {

        JSONObject object = new JSONObject();

        object.getJSONObject(resultado);

        return "O texto que voltou é:" + resultado;

    }

    private String consultaServidor() throws IOException {

        InputStream is = null;

        try {


            URL url = new URL(URL_STRING);

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

            conn.setReadTimeout(1000);

            conn.setConnectTimeout(15000);

            conn.setRequestMethod("GET");

            conn.setDoInput(true);

            conn.setDoOutput(false);

            conn.connect();

            conn.getResponseCode();

            is=conn.getInputStream();

            Reader reader = new InputStreamReader(is);
            char[] buffer = new char[22];
            reader.read(buffer);

            return new String(buffer);
        } finally {

            if (is !=null){

                is.close();
            }
        }
    }

    @Override
    protected void onPostExecute(String result) {

        listener.onConsultaConcluida(result);

    }

    public interface ConstultaSituacaoSitioListener {

        void onConsultaConcluida(String situacaositio);

    }

}

Xml :

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${packageName}.${activityClass}" >

    <TextView
        android:id="@+id/what"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
    />
</RelativeLayout>

Logcat error:

07-27 10:56:19.210: I/choreographer(1790): Skipped 48 frames! The application may be Doing Too Much work on its main thread. 07-27 10:56:19.970: D/dalvikvm(1790): GC_FOR_ALLOC Freed 241K, 10% free 2964K/3272K, paused 112ms, total 112ms 07-27 10:56:20.020: W/System.err(1790): org.json.Jsonexception: No value for Sour Chicken Casing 07-27 10:56:20.030: W/System.err(1790): at org.json.Jsonobject.get(Jsonobject.java:355) 07-27 10:56:20.030: W/System.err(1790): at org.json.Jsonobject.getJSONObject(Jsonobject.java:574) 07-27 10:56:20.030: W/System.err(1790): at com.example.consultsitio.ConsultSituacao.interpretaresult(Query.java:57) 07-27 10:56:20.030: W/System.err(1790): at com.example.consultsitio.ConsultSituacao.doInBackground(Query.java:35) 07-27 10:56:20.030: W/System.err(1790): at com.example.consultsitio.ConsultSituacao.doInBackground(Query.java:1) 07-27 10:56:20.030: W/System.err(1790): at android.os.Asynctask$2.call(Asynctask.java:288) 07-27 10:56:20.030: W/System.err(1790): at java.util.Concurrent.FutureTask.run(Futuretask.java:237) 07-27 10:56:20.030: W/System.err(1790): at android.os.Asynctask$Serialexecutor$1.run(Asynctask.java:231) 07-27 10:56:20.030: W/System.err(1790): at java.util.Concurrent.ThreadPoolExecutor.runWorker(Threadpoolexecutor.java:1112) 07-27 10:56:20.030: W/System.err(1790): at java.util.Concurrent.Threadpoolexecutor$Worker.run(Threadpoolexecutor.java:587) 07-27 10:56:20.030: W/System.err(1790): at java.lang.Thread.run(Thread.java:841)

Answer 1

Your code has two problems:

1. Is returning a String that is not in format JSON of a Webservice that should return JSON. That’s what I’d have to do:

   package com.rodasdo;
   
   import javax.ws.rs.Path;
   import javax.ws.rs.GET;
   import javax.ws.rs.Produces;
   
   @Path("/oi")
   public class Trator {
   
       @GET
       @Produces("application/json")
       public String returnTitle(){
           // Retorno JSON
           return "{\"resposta\": \"Tripa de Galinha azeda\"}";
       }
   }
   

2. Are you doing treating the answer of WebService incorrectly. Is not converting the String of response in the correct way. For this, you would have to build the JSON from the variable resultado and reclaim the field resposta (that has the text you need). That way:

   private String interpretaresultado(String resultado) throws JSONException {
   
       // Usar o construtor do JSONObject para "parsear" e representar o JSON na memória
       JSONObject object = new JSONObject(resultado);
   
       return "O texto que voltou é: " + object.getString("resposta");
   }