How to recover json data from a URL using HTTP POST on android?

Asked

Viewed 640 times

1

I need to recover values Json of a given URL using HTTP POST, but I’m having a hard time getting started. How can I perform such operation on Android?

android
  • 1

    Hello! You want to do it with Java Httppost, or you can use some library for it?

  • 1

    I have a feeling he won’t be able to answer your question either.

1 answer

1

On Android we can use some libraries to assist in this task as the Volley or Okhttp.

I will show an example with Okhttp:

Let’s add the libraries in build.Gradle: 

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs') 
    compile 'com.squareup.okhttp:okhttp:2.6.0' 
    compile 'com.google.code.gson:gson:2.3' // Tranforma Json para Objeto
}

To carry out a requisition, we have to separate it from the Thread main, so that it does not interfere with the graphical interface:

 private final class Send extends AsyncTask<Void, Void, Void>
    {

        final Context mContext;
        Send(final Context mContext)
        {
            this.mContext = mContext;
        }
        @Override
        protected Void doInBackground(Void... params) {

                final OkHttpClient mClient = new OkHttpClient();
                RequestBody body = null;
                Request.Builder requestBuilder = new Request.Builder();
                requestBuilder.url("www.url.com.br/send");
                final HashMap<String, String> mParams = new HashMap<>(0);

                mParams.put("param1", "Valo1" );
                mParams.put("param4", "Valor2" );
                mParams.put("param3", "Valor3" );

                final JSONObject jsonObject = new JSONObject(mParams);
                body = RequestBody.create(MediaType.parse("application/json"), jsonObject.toString());
                requestBuilder.post(body);
                OkHttpModel.loadHeaders(requestBuilder, mContext);

            try{
                final Response response = mClient.newCall(requestBuilder.build()).execute();
                final String txtResult = response.body().string();

                MeuObjeto meuObjeto = new Gson().fromJson(txtResult, MeuObjeto.class);


            }catch (final IOException e){ }


            return null;
        }
    }

The MeuObjeto must contain the same Json parameters returned by the request, and the same name:

     class MeuObjeto{

            private String valor_1;

            private Integer valor_2;

            private Boolean status;


// Get's and Set's

        }

If the names are different, we can map with Annotation: 

class MeuObjeto{

    @SerializedName("valor_1")
    private String valor1;

    @SerializedName("valor_2")
    private Integer valor2;

    @SerializedName("status")
    private Boolean valor3;

// Get's and Set's
}

Any questions, we are available!

Browser other questions tagged android

You are not signed in. Login or sign up in order to post.