How to parse json data with retrofit on Android

Question

ill try to be specific here. So i have created the most basic possible code just to test it and i am still unable to get the data, please help! Here is my code :

this is json output on my local server : http://localhost:8080/KokosinjacRestfull/rest/textService/mudriPevci

[{"id":1,"subCategory":"MudriPevci","title":"Mujo i haso","description":"Krenuli do Grada","author":"luka","date":"2016-06-13"},{"id":3,"subCategory":"mudriPevci","title":"Perica","description":"Pa on je napravio Haos","author":"luka","date":"2016-06-13"}]

Text.class :

package kokosinjac.com.digiart.koktest.models;

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;


public class Text {

@SerializedName("id")
@Expose
private Integer id;
@SerializedName("subCategory")
@Expose
private String subCategory;
@SerializedName("title")
@Expose
private String title;
@SerializedName("description")
@Expose
private String description;
@SerializedName("author")
@Expose
private String author;
@SerializedName("date")
@Expose
private String date;

/**
 * No args constructor for use in serialization
 *
 */


/**
 *
 * @param id
 * @param author
 * @param title
 * @param subCategory
 * @param description
 * @param date
 */


/**
 *
 * @return
 * The id
 */
public Integer getId() {
    return id;
}

/**
 *
 * @param id
 * The id
 */
public void setId(Integer id) {
    this.id = id;
}

/**
 *
 * @return
 * The subCategory
 */
public String getSubCategory() {
    return subCategory;
}

/**
 *
 * @param subCategory
 * The subCategory
 */
public void setSubCategory(String subCategory) {
    this.subCategory = subCategory;
}

/**
 *
 * @return
 * The title
 */
public String getTitle() {
    return title;
}

/**
 *
 * @param title
 * The title
 */
public void setTitle(String title) {
    this.title = title;
}

/**
 *
 * @return
 * The description
 */
public String getDescription() {
    return description;
}

/**
 *
 * @param description
 * The description
 */
public void setDescription(String description) {
    this.description = description;
}

/**
 *
 * @return
 * The author
 */
public String getAuthor() {
    return author;
}

/**
 *
 * @param author
 * The author
 */
public void setAuthor(String author) {
    this.author = author;
}

/**
 *
 * @return
 * The date
 */
public String getDate() {
    return date;
}

/**
 *
 * @param date
 * The date
 */
public void setDate(String date) {
    this.date = date;
}

}

Api interface.class :

package kokosinjac.com.digiart.koktest.retrofit;

import java.util.ArrayList;

import kokosinjac.com.digiart.koktest.models.Text; import retrofit2.Call; import retrofit2.http.GET; import retrofit2.http.Path;

public interface RetrofitAPInterface {

 @GET("rest/textService/{subCategory}") Call<ArrayList<Text>> getText(@Path("subCategory") String subCat);

}

class that displays data on the phone (you do not need to pay attention on some Strings, just look at the retrofit part,i;ve made it as simple as i can, subCatData.class:

public static final String BASE_URL ="http://localhost:8080/KokosinjacRestfull/";
HashMap<String,String> dataArr;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_sub_cat_data);
    final TextView tView = (TextView) findViewById(R.id.textView);
    Intent intent = getIntent();
    String urlSecondPartBefore = intent.getStringExtra("passedSubCat");
    String urlSecondPartAfter = urlSecondPartBefore.replaceAll("\\s", "");
    String urlFirstPart = intent.getStringExtra("passedUrlFirstPart");
    String catName = intent.getStringExtra("passedCatName");
    String data = null;
   // TextView test = (TextView) findViewById(R.id.test);


    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .build();
    RetrofitAPInterface apiService = retrofit.create(RetrofitAPInterface.class);
    Call<ArrayList<Text>> call = apiService.getText("mudriPevci");
    call.enqueue(new Callback<ArrayList<Text>>() {
        @Override
        public void onResponse(Call<ArrayList<Text>> call, Response<ArrayList<Text>> response) {
            int statusCode = response.code();
            ArrayList<Text> textArray = response.body();
            for (Text t : textArray){
                tView.setText(t.getDescription());
            }
          //  Log.i("DATA", "onResponse: "+text.getId());
        }

        @Override
        public void onFailure(Call<ArrayList<Text>> call, Throwable t) {

        }
    });

}

}

I am aware that the whole bunch of data is going to a simple label , but it is for testing purposes. Still i can not retrieve anything and i do not get any errors as well. Help would be much appreciated. Thanks!

Answer 1

I think problem with your URL if you are testing your App with android emulator then try like "http://10.0.2.2:8080/" . but if you are testing with device then you need to pass Your machine IP address like "http://192.143.1.0/" . and make sure that your device is connected with your machine on which your database is exits.

Answer 2

To parse JSON data on Android I highly recommend using JSOUP which you can find by clicking here it is simple, straight forward, and user friendly. Very easy to learn. Hope this helps you!

Answer 3

问题可能出在您的 BASE_URL 将您的 BASE_URL 更改为BASE_URL ="http://<your_local_ip_address>/KokosinjacRestfull/";

Answer 4

i hope the below example might help

     public void startFetching() {
    mApiManager.getFlowerApi().getFlowers(new Callback<String>() {
        @Override
        public void success(String s, Response response) {
            Log.d(TAG, "JSON :: " + s);

            try {
                JSONArray array = new JSONArray(s);

                for(int i = 0; i < array.length(); i++) {
                    JSONObject object = array.getJSONObject(i);

                    Flower flower = new Flower.Builder()
                            .setCategory(object.getString("category"))
                            .setPrice(object.getDouble("price"))
                            .setInstructions(object.getString("instructions"))
                            .setPhoto(object.getString("photo"))
                            .setName(object.getString("name"))
                            .setProductId(object.getInt("productId"))
                            .build();

                    mListener.onFetchProgress(flower);

                }

            } catch (JSONException e) {
                mListener.onFetchFailed();
            }


            mListener.onFetchComplete();
        }

        @Override
        public void failure(RetrofitError error) {
            Log.d(TAG, "Error :: " + error.getMessage());
            mListener.onFetchComplete();
        }
    });
}

Answer 5

the problem is with your URL Android can't hit your localhost ie http://localhost:8080 /KokosinjacRestfull/rest/textService/mudriPevci

up your server in specific IP and the run.The new IP would be like http://192.168.1.1 /KokosinjacRestfull/rest/textService/mudriPevci

Answer 6

使用 ip 地址而不是 localhost（从 url 替换 localhost 并将您的计算机的 ipaddress 作为 ip 地址打开 cmd 并键入 ipconfig 并替换 localhost）。