如何使用retrofit從可擴展列表視圖中加載json的數據？

我想加載問題和答案在可擴展列表視圖從JSON使用改造庫。我不知道如何做到這一點。找到我的解決方案。這是我使用的兩個模型類。如何使用retrofit從可擴展列表視圖中加載json的數據？

public class QuestionResult { 

boolean IsSuccess; 
List<QuestionsModel> question; 

public boolean isSuccess() { 
    return IsSuccess; 
} 

public List<QuestionsModel> getQuestion() { 
    return question; 
} 
}

而且

public class QuestionsModel { 
private int q_id; 
private int category_id; 
private String question; 
private String answer; 

public int getQ_id() { 
    return q_id; 
} 

public int getCategory_id() { 
    return category_id; 
} 

public String getQuestion() { 
    return question; 
} 

public String getAnswer() { 
    return answer; 
} 
}

這裏是我的活動

public class QuestionBank extends AppCompatActivity { 

@InjectView(R.id.ques_type_spinner) 
Spinner courseSpinner; 
@InjectView(R.id.home_btn_qbank) 
Button homeButton; 
@InjectView(R.id.no_questions) 
TextView textView; 
@InjectView(R.id.ques_ans_listview) 
ExpandableListView listView; 

List<String> courseNames; 
ArrayAdapter<String> courseAdapter; 
ExpandableListAdapter listAdapter; 
List<QuestionResult> resultList; 
ProgressDialog progress; 
int selectedPosition; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_question_bank); 
    ButterKnife.inject(this); 
    StatusBarTheme.setStatusBarColor(this); 

    showCourseCategory(); 
    homeButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      finish(); 
     } 
    }); 

    courseSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { 
     @Override 
     public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { 
      selectedPosition = courseSpinner.getSelectedItemPosition() + 1; 
      Log.d("cat_id ", " " + selectedPosition); 
      loadQuestions(selectedPosition); 
     } 

     @Override 
     public void onNothingSelected(AdapterView<?> parent) { 

     } 
    }); 
} 

private void loadQuestions(final int selectedPosition) { 

    ApiInterface apiInterface = ApiClient.getClient(this).create(ApiInterface.class); 
    Call<QuestionResult> call = apiInterface.loadQuesAndAnswers(selectedPosition); 

    call.enqueue(new Callback<QuestionResult>() { 
     @Override 
     public void onResponse(Call<QuestionResult> call, Response<QuestionResult> response) { 

      List<QuestionsModel> questionsModelList = response.body().getQuestion(); 
      if (questionsModelList != null) { 

       listAdapter = new ExpandListAdapter(QuestionBank.this, questionsModelList, selectedPosition); 
       listView.setAdapter(listAdapter); 

      } else { 
       listView.setVisibility(View.GONE); 
       textView.setVisibility(View.VISIBLE); 
      } 

     } 

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

     } 
    }); 
} 

private void showCourseCategory() { 

    ApiInterface apiInterface = ApiClient.getClient(this).create(ApiInterface.class); 
    Call<CategoryResult> call = apiInterface.loadCourseTitle(); 
    progress = new ProgressDialog(QuestionBank.this); 
    progress.setMessage("Loading.. Please wait"); 
    progress.show(); 

    call.enqueue(new Callback<CategoryResult>() { 
     @Override 
     public void onResponse(Call<CategoryResult> call, Response<CategoryResult> response) { 

      if (progress.isShowing()) { 
       progress.dismiss(); 
      } 

      if (response.body().isSuccess() && response.body().getCategory() != null) { 
       response.body().getCategory(); 
       courseNames = new ArrayList<>(); 
       for (CourseType courseType : response.body().getCategory()) { 
        courseNames.add(courseType.getCategory_title()); 
       } 
       loadSpinner(courseNames); 
      } 
     } 

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

     } 

    }); 
} 

private void loadSpinner(List<String> educationTypeList) { 
    courseAdapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, educationTypeList); 
    courseAdapter.setDropDownViewResource(android.R.layout.simple_list_item_checked); 
    courseSpinner.setAdapter(courseAdapter); 
} 
}

來源

2016-11-18 Bakya

可以實現，使用和改造，例如傑克遜。這將返回你簡單的java對象。 –

建議我一些樣品 – Bakya

我不熟悉使用傑克遜 – Bakya

下面是完整的代碼。改變它爲你的目的。如果會發生任何事情，你可以寫評論，我會回答。

Application.class

public class Application extends Application{ 

    private static Application instance; 
    private I_Requests iWebEndpoint; 

    @Override 
    public void onCreate() { 
     super.onCreate(); 
     instance = this; 
    } 

    public static Application i() { 
     return instance; 
    } 


    public I_Requests w() { 
     if(this.iWebEndpoint == null){ 
      initRetrofit(); 
     } 
     return iWebEndpoint; 
    } 

    private void initRetrofit(){ 

     HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor(); 
     interceptor.setLevel(HttpLoggingInterceptor.Level.BODY); 
     OkHttpClient client = new OkHttpClient 
       .Builder() 
       .addInterceptor(interceptor) 
       .readTimeout(1, TimeUnit.MINUTES) 
       .writeTimeout(1, TimeUnit.MINUTES) 
       .connectTimeout(1, TimeUnit.MINUTES) 
       .build(); 

     client.readTimeoutMillis(); 

     this.iWebEndpoint = new Retrofit.Builder() 
       .baseUrl(I_Requests.address) 
       .client(client) 
       .addConverterFactory(JacksonConverterFactory.create()) 
       .build() 
       .create(I_Requests.class); 
    } 
}

JacksonConverterFactory.class

import com.fasterxml.jackson.databind.JavaType; 
import com.fasterxml.jackson.databind.ObjectMapper; 
import com.fasterxml.jackson.databind.ObjectReader; 
import com.fasterxml.jackson.databind.ObjectWriter; 

import java.lang.annotation.Annotation; 
import java.lang.reflect.Type; 

import okhttp3.RequestBody; 
import okhttp3.ResponseBody; 
import retrofit2.Converter; 
import retrofit2.Retrofit; 

/** 
* A {@linkplain Converter.Factory converter} which uses Jackson. 
* <p> 
* Because Jackson is so flexible in the types it supports, this converter assumes that it can 
* handle all types. If you are mixing JSON serialization with something else (such as protocol 
* buffers), you must {@linkplain Retrofit.Builder#addConverterFactory(Converter.Factory) add this 
* instance} last to allow the other converters a chance to see their types. 
*/ 
public final class JacksonConverterFactory extends Converter.Factory { 
    /** Create an instance using a default {@link ObjectMapper} instance for conversion. */ 
    public static JacksonConverterFactory create() { 
    return create(new ObjectMapper()); 
    } 

    /** Create an instance using {@code mapper} for conversion. */ 
    public static JacksonConverterFactory create(ObjectMapper mapper) { 
    return new JacksonConverterFactory(mapper); 
    } 

    private final ObjectMapper mapper; 

    private JacksonConverterFactory(ObjectMapper mapper) { 
    if (mapper == null) throw new NullPointerException("mapper == null"); 
    this.mapper = mapper; 
    } 

    @Override 
    public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, 
     Retrofit retrofit) { 
    JavaType javaType = mapper.getTypeFactory().constructType(type); 
    ObjectReader reader = mapper.reader(javaType); 
    return new JacksonResponseBodyConverter<>(reader); 
    } 

    @Override 
    public Converter<?, RequestBody> requestBodyConverter(Type type, 
     Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) { 
    JavaType javaType = mapper.getTypeFactory().constructType(type); 
    ObjectWriter writer = mapper.writerWithType(javaType); 
    return new JacksonRequestBodyConverter<>(writer); 
    } 
}

JacksonRequestBodyConverter.class

import com.fasterxml.jackson.databind.ObjectWriter; 

import java.io.IOException; 

import okhttp3.MediaType; 
import okhttp3.RequestBody; 
import retrofit2.Converter; 

final class JacksonRequestBodyConverter<T> implements Converter<T, RequestBody> { 
    private static final MediaType MEDIA_TYPE = MediaType.parse("application/json; charset=UTF-8"); 

    private final ObjectWriter adapter; 

    JacksonRequestBodyConverter(ObjectWriter adapter) { 
    this.adapter = adapter; 
    } 

    @Override public RequestBody convert(T value) throws IOException { 
    byte[] bytes = adapter.writeValueAsBytes(value); 
    return RequestBody.create(MEDIA_TYPE, bytes); 
    } 
}

個

JacksonResponseBodyConverter.class

import com.fasterxml.jackson.databind.ObjectReader; 

import java.io.IOException; 

import okhttp3.ResponseBody; 
import retrofit2.Converter; 

final class JacksonResponseBodyConverter<T> implements Converter<ResponseBody, T> { 
    private final ObjectReader adapter; 

    JacksonResponseBodyConverter(ObjectReader adapter) { 
    this.adapter = adapter; 
    } 

    @Override public T convert(ResponseBody value) throws IOException { 
    try { 
     return adapter.readValue(value.charStream()); 
    } finally { 
     value.close(); 
    } 
    } 
}

I_Request.interface

import java.util.ArrayList; 

import manqaro.com.projectz.ServerSide.Response.TestData; 
import manqaro.com.projectz.ServerSide.Response.TestResponse; 
import retrofit2.Call; 
import retrofit2.http.Field; 
import retrofit2.http.FormUrlEncoded; 
import retrofit2.http.GET; 
import retrofit2.http.POST; 

public interface I_Requests { 

    //PUT HERE YOUR SERVER MAIN ADDRES 
    String address = "http://goto.xcodes.club"; 

    //SAMPLE EXAMPLE OF POST TYPE , YOU SHOULD CHANGE EVERYTHING YOU WANT. 
    //IN THIS EXAMPLE YOU WILL GET JSON DATA WHICH WILL BE CONVERTED TO JAVA OBJECT. 
    @FormUrlEncoded 
    //Here YOU HAVE TO GIVE ADDRESS TO SPECIFIC CALL 
    @GET("/api/v1/objects/") 
    Call<TestResponse<ArrayList<TestData>>> login(
    ); 


    @FormUrlEncoded 
    @POST("/api/v1/objects/") 
    Call<TestResponse<ArrayList<TestData>>> register(
    ); 
}

TestResponse.class

import com.fasterxml.jackson.annotation.JsonProperty; 

/** 
* Created by ArsenSench on 11/9/2016. 
*/ 

public class TestResponse<T> { 
    @JsonProperty("status") 
    public int status; 

    @JsonProperty("message") 
    public String message; 

    @JsonProperty("data") 
    public T data; 

}

TestData.class

import com.fasterxml.jackson.annotation.JsonProperty; 


/** 
* Created by ArsenSench on 11/9/2016. 
*/ 

public class TestData extends { 

    @JsonProperty("id") 
    public int id; 

    @JsonProperty("name") 
    public String name; 

    @JsonProperty("description") 
    public String description; 

    @JsonProperty("avatar") 
    public String avatar; 

    @JsonProperty("rate") 
    public int rate; 
}

ServerCalls.class

import android.content.Context; 
import android.util.Log; 
import android.widget.Toast; 
import java.util.ArrayList; 
import manqaro.com.projectz.ServerSide.Application.Tickle_Application; 
import manqaro.com.projectz.ServerSide.Response.TestData; 
import manqaro.com.projectz.ServerSide.Response.TestResponse; 
import retrofit2.Call; 
import retrofit2.Callback; 
import retrofit2.Response; 

/** 
* Created by ArsenSench on 11/9/2016. 
*/ 

public class ServerCalls { 
    Context context; 
    public ServerCalls(Context context){ 
     this.context = context; 
    } 

    public void testCallBack(){ 

     Tickle_Application.i().w().login().enqueue(new Callback<TestResponse<ArrayList<TestData>>>() { 
      @Override 
      public void onResponse(Call<TestResponse<ArrayList<TestData>>> call, Response<TestResponse<ArrayList<TestData>>> response) { 
       if(response.code()==200){ 
        if(response.body().status==200){ 

         Toast.makeText(context, response.body().data.get(0).name, Toast.LENGTH_SHORT).show(); 

        } 

        else{ 
         Toast.makeText(context, "No Name", Toast.LENGTH_SHORT).show(); 
        } 
       } 

       else{ 

        Toast.makeText(context, "No Connection", Toast.LENGTH_SHORT).show(); 
       } 
      } 

      @Override 
      public void onFailure(Call<TestResponse<ArrayList<TestData>>> call, Throwable t) { 
       Toast.makeText(context, t.getCause().getMessage(), Toast.LENGTH_SHORT).show(); 
       Log.e("jex", "onFailure: " + t.getCause().getMessage()); 
      } 
     }); 
     } 
     }

TestActivity.activity

import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.view.View; 

import manqaro.com.projectz.R; 
import manqaro.com.projectz.ServerSide.Main.ServerCalls; 

public class TestActivity extends AppCompatActivity { 
    ServerCalls sc = new ServerCalls(this); 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_test); 
    } 

    public void clickThatShit(View view){ 

     sc.testCallBack(); 
    } 
}

艙單

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    package="your.package.name"> 

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

    <application 
     android:name=".Application" 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:label="@string/app_name" 
     android:largeHeap="true" 
     android:supportsRtl="true" 
     android:theme="@style/AppTheme" 
     tools:replace="android:icon"> 
     <activity 
      android:name=".TestActivity"> 

     </activity> 

    </application> 

</manifest>

的build.gradle（模塊的應用程序） 納入yourdependencies

compile 'com.squareup.retrofit2:retrofit:2.0.0' 
    compile 'com.squareup.okhttp3:logging-interceptor:3.2.0' 
    compile 'com.fasterxml.jackson.core:jackson-databind:2.7.3' 
    compile 'com.fasterxml.jackson.core:jackson-annotations:2.7.3'

這些依賴包括在你的Android此行{}塊

packagingOptions { 
     exclude 'META-INF/LICENSE' 
     exclude 'META-INF/NOTICE' 
    }

來源

2016-11-18 13:01:10

如何使用retrofit從可擴展列表視圖中加載json的數據？

回答

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