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android - OkHttp3 响应在 android 的自定义适配器类中显示错误

问题描述

我正在使用 OkHttp3 从服务器获取数据我有自定义适配器类，其中我在单击按钮时在回收器视图项中有一个按钮我正在向服务器发送请求并获得响应。

但是在得到回复时，我收到了错误：

2020-02-14 23:23:23.222 10597-12522/com.example.aamkuconnect E/AndroidRuntime: FATAL EXCEPTION: OkHttp Dispatcher
Process: com.example.aamkuconnect, PID: 10597
java.lang.ClassCastException: androidx.multidex.MultiDexApplication cannot be cast to com.example.aamkuconnect.AdminNewOrders

下面是我的代码：

AdminNewOrders.class

public class AdminNewOrders extends AppCompatActivity {

RecyclerView adminSeeOrder;
ProgressBar my_prog;
AdminSeeNewOrderAdapter adapter;
List<AdminSeeNewOrderModel> list = new ArrayList<>();

private static final String URL = "https://www.example.com";

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

    ActionBar ab = getSupportActionBar();
    assert ab!= null;
    ab.setTitle("New orders");
    ab.setDisplayHomeAsUpEnabled(true);

    my_prog = findViewById(R.id.my_prog);
    adminSeeOrder = findViewById(R.id.adminSeeOrder);
    adminSeeOrder.setHasFixedSize(true);
    adminSeeOrder.setLayoutManager(new LinearLayoutManager(this));

    newOrders();

}

private void newOrders(){

    OkHttpClient client = new OkHttpClient.Builder()
            .connectTimeout(20, TimeUnit.SECONDS)
            .readTimeout(20,TimeUnit.SECONDS)
            .writeTimeout(20,TimeUnit.SECONDS)
            .build();

    RequestBody formBody = new FormBody.Builder()
            .add("order_status","pending")
            .build();

    Request request = new Request.Builder().post(formBody).url(URL).build();

    client.newCall(request).enqueue(new Callback() {

        @Override
        public void onResponse(@NotNull Call call, @NotNull final Response response) throws IOException {

            runOnUiThread(new Runnable() {
                @Override
                public void run() {

                    try {

                        JSONArray jsonArray = new JSONArray(response.body().string());

                        if(jsonArray.length() > 0){

                            my_prog.setVisibility(View.INVISIBLE);

                            for(int i = jsonArray.length()-1;i>-1;i--){

                                JSONObject jsonObject = jsonArray.getJSONObject(i);

                                String str1 = jsonObject.getString("name");

                                AdminSeeNewOrderModel model = new AdminSeeNewOrderModel(str1);
                                list.add(model);

                            }

                            adapter = new AdminSeeNewOrderAdapter(list,getApplicationContext());
                            adminSeeOrder.setAdapter(adapter);
                        }

                    } catch (JSONException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }

        @Override
        public void onFailure(@NotNull Call call, @NotNull final IOException e) {

            runOnUiThread(new Runnable() {
                @Override
                public void run() {

                    my_prog.setVisibility(View.INVISIBLE);
                   Toast.makeText(getApplicationContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
                }
            });
        }
    });


}

@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {

    switch(item.getItemId()){

        case android.R.id.home:

            Intent i = new Intent(AdminNewOrders.this,Dashboard.class);
            startActivity(i);
            finish();
            break;
    }

    return super.onOptionsItemSelected(item);
  }
}

AdminSeeNewOrderAdapter.class 

public class AdminSeeNewOrderAdapter extends RecyclerView.Adapter<AdminSeeNewOrderAdapter.ViewHolder> {

List<AdminSeeNewOrderModel> list = new ArrayList<>();
Context context;

private static final String URL = "https://example.com";

public AdminSeeNewOrderAdapter(List<AdminSeeNewOrderModel> list, Context context) {
    this.list = list;
    this.context = context;
}

@NonNull
@Override
public AdminSeeNewOrderAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.admin_see_new_order_row,parent,false);

    ViewHolder viewHolder = new ViewHolder(v);
    return viewHolder;
}

@Override
public void onBindViewHolder(@NonNull final AdminSeeNewOrderAdapter.ViewHolder holder, final int position) {

    final AdminSeeNewOrderModel model = list.get(position);

     holder.adSeeName.setText(model.getName());

    holder.accept.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

               acceptOrders(position);

        }
    });

}

@Override
public int getItemCount() {
    return list.size();
}

public class ViewHolder extends RecyclerView.ViewHolder {

    TextView adSeeName,adSeeDate,adSeePhone,adSeeAdr,prodName,prodCost,viewDetails,accept,cancel;

    public ViewHolder(@NonNull View itemView) {
        super(itemView);

           TextView  adSeeName = itemView.findViewById(R.id.adSeeName);
          Textview  accept = itemView.findViewById(R.id.accept);

    }
}

private void acceptOrders(String mobile, String product, String date, final int position){

    OkHttpClient client = new OkHttpClient.Builder()
            .connectTimeout(20, TimeUnit.SECONDS)
            .readTimeout(20,TimeUnit.SECONDS)
            .writeTimeout(20,TimeUnit.SECONDS)
            .build();

    RequestBody formBody = new FormBody.Builder()
            .add("phone",mobile)
            .add("date",date)
            .add("product",product)
            .build();

    Request request = new Request.Builder().post(formBody).url(URL).build();

    client.newCall(request).enqueue(new Callback() {

        @Override
        public void onResponse(@NotNull Call call, @NotNull final Response response) throws IOException {

            ((AdminNewOrders)context).runOnUiThread(new Runnable() {
                @Override
                public void run() {

                    try {

                        String resp = response.body().string();

                         if(resp.equals("Updated successfully")){

                             list.remove(position);
                             notifyItemRemoved(position);
                         }


                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }

        @Override
        public void onFailure(@NotNull Call call, @NotNull final IOException e) {

            ((AdminNewOrders)context).runOnUiThread(new Runnable() {
                @Override
                public void run() {


                    Toast.makeText(context,e.getMessage(),Toast.LENGTH_SHORT).show();
                }
            });
        }
    });
  }
}

构建.gradle

apply plugin: 'com.android.application'

android {
compileSdkVersion 29
buildToolsVersion "29.0.2"
defaultConfig {
    applicationId "com.example.aamkuconnect"
    minSdkVersion 16
    targetSdkVersion 29
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    multiDexEnabled true
  }
 buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
      }
   }
}

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'androidx.appcompat:appcompat:1.1.0'

implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
implementation 'androidx.legacy:legacy-support-v4:1.0.0'
implementation 'androidx.navigation:navigation-fragment:2.1.0'
implementation 'androidx.navigation:navigation-ui:2.1.0'
implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'
testImplementation 'junit:junit:4.12'
implementation 'com.google.firebase:firebase-analytics:17.2.0'
implementation 'com.google.firebase:firebase-auth:19.2.0'
androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
implementation 'androidx.cardview:cardview:1.0.0'
implementation 'com.google.android.material:material:1.0.0'
implementation 'androidx.recyclerview:recyclerview:1.1.0'
implementation 'com.squareup.okhttp3:okhttp:4.2.1'
implementation 'androidx.multidex:multidex:2.0.1'

}

apply plugin: 'com.google.gms.google-services'

有人请让我知道如何解决此错误。任何帮助将不胜感激。

谢谢

标签： android

解决方案

我可以告诉你很多事情为什么会发生：

  1. 适配器不应进行 http 调用
  2. 适配器不应进行 ui 调用（Toast.makeText ...）

  3. 还有其他方法可以在不调用 runOnUiThread 的情况下返回 ui 线程，例如

       new Handler(Looper.getMainLooper()).post(new Runnable {
       override void run(){ 
          Toast.makeText...
         }
   });

但是你的主要问题是，你提供的上下文是一个应用程序上下文，并且没有附加到任何 UiThread，如果你仍然想这样做，你需要传递 Activity 上下文，甚至确保上下文仍然有效。

改变这个：

   adapter = new AdminSeeNewOrderAdapter(list,getApplicationContext());

对此：

   adapter = new AdminSeeNewOrderAdapter(list, AdminNewOrders.this);

它会起作用的。

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