的Android Recyclerview，okhttp，收到java.lang.ClassCastException錯誤

Question

我試圖通過URL okhttp調用的數據加載到我recyclerview，和我收到以下錯誤：

「java.lang.ClassCastException：SearchActivity無法投射到SearchForBarbershop $ BarbershopRequesterResponse「

這裏是類。

SearchActivity：

public class SearchActivity extends AppCompatActivity { 

private RecyclerAdapter mAdapter; 
private RecyclerView mRecyclerView; 
private LinearLayoutManager mLinearLayoutManager; 

private ArrayList<Barbershop> barbershopList; 
private SearchForBarbershop searchForBarbershop; 

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

    mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view); 
    mLinearLayoutManager = new LinearLayoutManager(this); 
    mRecyclerView.setLayoutManager(mLinearLayoutManager); 

    barbershopList = new ArrayList<>(); 
    mAdapter = new RecyclerAdapter(barbershopList); 
    mRecyclerView.setAdapter(mAdapter); 
    setRecyclerViewScrollListener(); 
    searchForBarbershop = new SearchForBarbershop(this); 
} 

@Override 
protected void onStart() { 
    super.onStart(); 
    if (barbershopList.size() == 0) { 
     requestShop(); 
    } 
} 

private int getLastVisibleItemPosition() { 
    return mLinearLayoutManager.findLastVisibleItemPosition(); 
} 

private void setRecyclerViewScrollListener() { 
    mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() { 
     @Override 
     public void onScrollStateChanged(RecyclerView recyclerView, int newState) { 
      super.onScrollStateChanged(recyclerView, newState); 
      int totalItemCount = mRecyclerView.getLayoutManager().getItemCount(); 
      if (!searchForBarbershop.isLoadingData() && totalItemCount == getLastVisibleItemPosition() + 1) { 
       requestShop(); 
      } 
     } 
    }); 
} 

private void requestShop() { 

    try { 
     searchForBarbershop.getBarbershop(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
} 

//@Override 
public void receivedNewShop(final Barbershop newBarbershop) { 

    runOnUiThread(new Runnable() { 
     @Override 
     public void run() { 
      barbershopList.add(newBarbershop); 
      mAdapter.notifyItemInserted(barbershopList.size()); 
     } 
    }); 
} 

}

SearchForBarbershop：

public class SearchForBarbershop { 

public interface BarbershopRequesterResponse { 
    void receivedNewBarbershop(Barbershop barbershop); 
} 

private BarbershopRequesterResponse barbershopRequesterResponse; 
private OkHttpClient client; 
private boolean isLoadingData; 

public boolean isLoadingData() { return isLoadingData; } 

public SearchForBarbershop (Activity listeningActivity) { 
    client = new OkHttpClient(); 
    isLoadingData = false; 
    barbershopRequesterResponse = (BarbershopRequesterResponse) listeningActivity; 
} 

public void getBarbershop() throws IOException { 
    String url = "http://pubapi.yp.com/search-api/search/devapi/search?searchloc=30043&term=barbers&format=json&sort=distance&radius=50&listingcount=20&key=gmj3x7mhsh"; 
    Request request = new Request.Builder().url(url).build(); 
    isLoadingData = true; 

    client.newCall(request).enqueue(new Callback() { 
     @Override 
     public void onFailure(Call call, IOException e) { 
      isLoadingData = false; 
      e.printStackTrace(); 
     } 

     @Override 
     public void onResponse(Call call, Response response) throws IOException { 
      try { 
       JSONObject object = new JSONObject(response.body().string()); 

        Barbershop receivedShop = new Barbershop(object); 
        barbershopRequesterResponse.receivedNewBarbershop(receivedShop); 
        isLoadingData = false; 

      } catch (JSONException e) { 
       isLoadingData = false; 
       e.printStackTrace(); 
      } 
     } 
    }); 
} 

}

理髮：

public class Barbershop{ 

private String name; 
private String city; 

public Barbershop(JSONObject barbershopJSON) { 

    try { 
     JSONArray businessArray = barbershopJSON.getJSONObject("searchResult").getJSONObject("searchListings").getJSONArray("searchListing"); 

     for(int i = 0; i < businessArray.length(); i++) { 

      //Parse JSON and assign to variables 
      JSONObject business_object_1 = businessArray.getJSONObject(i); 
      String primaryc = business_object_1.getString("primaryCategory"); 
      //Check to make sure the main category is "Barbers" 
      if((primaryc).equals("Barbers")) { 

       name = business_object_1.getString("businessName"); 
       city = business_object_1.getString("city"); 

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

public String getCity() { 
    return city; 
} 

public String getName() { 
    return name; 
} 

}

RecyclerAdapter：

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ShopHolder> { 

private ArrayList<Barbershop> mbarbershops; 

public RecyclerAdapter(ArrayList<Barbershop> barbershops) { 
    mbarbershops = barbershops; 
} 

@Override 
public RecyclerAdapter.ShopHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    View inflatedView = LayoutInflater.from(parent.getContext()) 
      .inflate(R.layout.cardview_barber_search, parent, false); 
    return new ShopHolder(inflatedView); 
} 

@Override 
public void onBindViewHolder(RecyclerAdapter.ShopHolder holder, int position) { 
    Barbershop itemBarbershop = mbarbershops.get(position); 
    holder.bindShop(itemBarbershop); 
} 

@Override 
public int getItemCount() { 
    return 0; 
} 

public static class ShopHolder extends RecyclerView.ViewHolder implements View.OnClickListener { 

    private TextView mName; 
    private TextView mCity; 

    public ShopHolder(View view) { 
     super(view); 

     mName = (TextView) view.findViewById(R.id.textViewName); 
     mCity = (TextView) view.findViewById(R.id.textViewCity); 
     view.setOnClickListener(this); 

    } 

    @Override 
    public void onClick(View v) { 

    } 

    public void bindShop(Barbershop barbershop) { 
     mName.setText(barbershop.getName()); 
     mCity.setText(barbershop.getCity()); 
    } 
} 

}

Answer 1

它不能被轉換，因爲它沒有實現該接口。您評論的@override聲明應該是您在這裏的線索。

將其更改爲：

public class SearchActivity extends AppCompatActivity 
    implements SearchForBarbershop.BarbershopRequesterResponse { 

.... 

而且不要忘記刪除的方法來實現你的評論：

@Override 
public void receivedNewShop(final Barbershop newBarbershop) { 
.... 

Answer 2

我認爲你需要改變構造SearchForBarbershop

BarbershopRequesterResponse listener; 
Context context 
public SearchForBarbershop (Context context,BarbershopRequesterResponse listener) { 
    client = new OkHttpClient(); 
    isLoadingData = false; 
    this.context = context; 
    this.listener = listener; 
} 

，並更改SearchActivity

searchForBarbershop = new SearchForBarbershop(SearchActivity.this, this);