我正在解析一个Ola Cabs API，其响应如下：
{
"categories": [
{
"id": "mini",
"display_name": "Mini",
"currency": "INR",
"distance_unit": "kilometre",
"time_unit": "minute",
"eta": 1,
"distance": "0.2",
"ride_later_enabled": "true",
"image": "http://d1foexe15giopy.cloudfront.net/mini.png",
"fare_breakup": [
{
"type": "flat_rate",
"minimum_distance": "4",
"minimum_time": "0",
"base_fare": "80",
"minimum_fare": "0",
"cost_per_distance": "10",
"waiting_cost_per_minute": "0",
"ride_cost_per_minute": "1",
"rates_higher_than_usual": false,
"surcharge": []
},
{
"type": "airport_rate",
"minimum_distance": "25",
"minimum_time": "0",
"base_fare": "499",
"minimum_fare": "0",
"cost_per_distance": "13",
"waiting_cost_per_minute": "0",
"ride_cost_per_minute": "1",
"rates_higher_than_usual": false,
"surcharge": []
}
],
"cancellation_policy": {
"cancellation_charge": 50,
"currency": "INR",
"cancellation_charge_applies_after_time": 5,
"time_unit": "minute"
}
}
],
"ride_estimate": {}
}
我已经将Model类创建为：
public class ListOfEstimateTimeForOla() {
List<Categories> categories;
//getter of categories
}
上面的课程是我得到所有答案的主要POJO。下面给出了另一个POJO命名 - 类别。
public class Categories() {
List<Fare_breakup>;
//getter of Fare_breakup
}
并且有一个定义为Fare_breakup的模型，如下所示：
public class Fare_breakup {
int base_fare;
//getter of fare
}
现在，我在我的片段中得到了响应，其代码如下：
requestInterface = retrofit.create(RideRequestInterface.class);
if (pickup_lat != 0 && pickup_long != 0 ) {
Call<ListOfEstimateTimeForOla> priceData = requestInterface.getEstimateTimeForOla(pickup_lat, pickup_long);
priceData.enqueue(new Callback<ListOfEstimateTimeForOla>() {
@Override
public void onResponse(@NonNull Call<ListOfEstimateTimeForOla> call, @NonNull Response<ListOfEstimateTimeForOla> response) {
int statusCode = response.code();
ListOfEstimateTimeForOla data = response.body();
assert data != null;
EstimateTimeAdapterForOla adapter = new EstimateTimeAdapterForOla(data.getCategories(), getContext());
estimatePriceForOla.setAdapter(adapter);
progressForOla.setVisibility(View.GONE);
estimatePriceForOla.setVisibility(View.VISIBLE);
Log.d("Estimated Time for Ola", "onResponse: "+ statusCode);
}
@Override
public void onFailure(@NonNull Call<ListOfEstimateTimeForOla> call, @NonNull Throwable t) {
Log.d("Estimated Time for Ola", "onResponse: "+ t.getMessage());
}
});
}
我需要在我的RecyclerView中获取其适配器类如下的票价：
public class EstimateTimeAdapterForOla extends RecyclerView.Adapter<EstimateTimeAdapterForOla.EstimateTimeHolder>{
private Context c;
private List<EstimateTimeForOla> estimateTimeForOla;
public EstimateTimeAdapterForOla (List<EstimateTimeForOla> estimateTimeForOla, Context c) {
this.estimateTimeForOla = estimateTimeForOla;
this.c = c;
}
@Override
public EstimateTimeHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.estimate_time_for_ola, parent, false);
EstimateTimeHolder holder = new EstimateTimeHolder(view);
return holder;
}
@Override
public void onBindViewHolder(EstimateTimeHolder holder, int position) {
holder.displayName.setText(estimateTimeForOla.get(position).getDisplay_name());
Picasso.with(c).load(estimateTimeForOla.get(position).getImage()).into(holder.displayIcon);
holder.fare.setText(String.valueOf(estimateTimeForOla.get(position).getFare_breakup().get(0).getBase_fare()));
holder.eta.setText(String.valueOf(estimateTimeForOla.get(position).getEta()));
}
@Override
public int getItemCount() {
return estimateTimeForOla.size();
}
public static class EstimateTimeHolder extends RecyclerView.ViewHolder {
TextView displayName, fare, eta;
ImageView displayIcon;
public EstimateTimeHolder(View itemView) {
super(itemView);
displayName = itemView.findViewById(R.id.display_name_ola_tv);
fare = itemView.findViewById(R.id.actual_fare_tv);
eta = itemView.findViewById(R.id.actual_eta_tv);
displayIcon = itemView.findViewById(R.id.display_icon_ola_iv);
}
}
}
现在，我的问题是如何通过onBindViewHolder获取我的recyclerview中的票价？
以下是运行上述代码后的错误：
07-28 17:27:50.134 330-330/test.android.mobond.tabs.slidingtabs E/AndroidRuntime: FATAL EXCEPTION: main
Process: test.android.mobond.tabs.slidingtabs, PID: 330
java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object java.util.List.get(int)' on a null object reference
at test.android.mobond.tabs.slidingtabs.adapters.EstimateTimeAdapterForOla.onBindViewHolder(EstimateTimeAdapterForOla.java:45)
at test.android.mobond.tabs.slidingtabs.adapters.EstimateTimeAdapterForOla.onBindViewHolder(EstimateTimeAdapterForOla.java:22)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6400)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6433)
at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5377)
at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5640)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5482)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5478)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2215)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1542)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1502)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:595)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3625)
at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3067)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:18870)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1629)
at android.view.View.measure(View.java:18870)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:464)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)
at android.view.View.measure(View.java:18870)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5908)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:436)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:3076)
at android.view.View.measure(View.java:18870)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2392)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1416)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1661)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1301)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7016)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
at android.view.Choreographer.doCallbacks(Choreographer.java:590)
at android.view.Choreog
答案 0 :(得分：1)
使用JSON2POJO创建POJO以创建足够的POJO类并使用Retrofit
答案 1 :(得分：0)
我用它来获取天气详情。这个例子是获取数据的完全不同的方法。我认为这对你有用。
private static JSONObject getObject(String tagName, JSONObject jObj) throws JSONException {
JSONObject subObj = jObj.getJSONObject(tagName);
return subObj;
}
private static JSONArray getArray(String tagName, JSONObject jObj) throws JSONException {
JSONArray subObj = jObj.getJSONArray(tagName);
return subObj;
}
private static String getString(String tagName, JSONObject jObj) throws JSONException {
return jObj.getString(tagName);
}
private static float getFloat(String tagName, JSONObject jObj) throws JSONException {
return (float) jObj.getDouble(tagName);
}
private static int getInt(String tagName, JSONObject jObj) throws JSONException {
return jObj.getInt(tagName);
}
//weatherMethod
private void getWeather(String city){
String url = String.format(EndPoints.getWeather, city);
pd.show();
JsonRequest req = new JsonRequest(Request.Method.GET, url, null, new com.android.volley.Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
if (pd != null) pd.cancel();
try {
Timber.d("find Weather : %s", response.toString() + " ID - "+response.get("id"));
try {
JSONObject coordObj = getObject("coord", response);
Log.d("TAG"," lat "+getFloat("lat", coordObj));
Log.d("TAG"," lon "+getFloat("lon", coordObj));
JSONObject sysObj = getObject("sys", response);
Log.d("TAG"," country "+getString("country", sysObj));
Log.d("TAG"," sunrise "+getInt("sunrise", sysObj));
Log.d("TAG"," sunset "+getInt("sunset", sysObj));
Log.d("TAG"," name "+getString("name", response));
JSONObject mainObj = getObject("main", response);
Log.d("TAG"," temp "+getFloat("temp", mainObj));
Log.d("TAG"," pressure "+getInt("pressure", mainObj));
Log.d("TAG"," humidity "+getInt("humidity", mainObj));
JSONArray weatherArray = getArray("weather", response);
JSONObject weatherObj = weatherArray.getJSONObject(0);
//JSONObject weatherObj = getObject("main", weatherArray.getJSONObject(0));
Log.d("TAG"," main "+getString("main", weatherObj));
Log.d("TAG"," description "+getString("description", weatherObj));
Log.d("TAG"," ***- icon -*** "+getString("icon", weatherObj));
//"http://openweathermap.org/img/w/"+getString("icon", weatherObj)+".png";
JSONObject cloudsObj = getObject("clouds", response);
Log.d("TAG"," all "+getInt("all", cloudsObj));
JSONObject windObj = getObject("wind", response);
Log.d("TAG"," speed "+getFloat("speed", windObj));
Log.d("TAG"," deg "+getInt("deg", windObj));
description = getString("description", weatherObj);
lastUpdate = getString("dt", response);
humidity = getInt("humidity", mainObj);
clouds = getInt("all", cloudsObj);
temperature = String.valueOf(getFloat("temp", mainObj));
pressure = String.valueOf(getInt("pressure", mainObj));
wind = getString("speed", windObj);
sunrise = String.valueOf(getInt("sunrise", sysObj));
sunset = String.valueOf(getInt("sunset", sysObj));
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(getString("name", response));
preLoadWeather();
//weather.location = loc;
} catch (JSONException e) {
e.printStackTrace();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new com.android.volley.Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
if (pd != null) pd.cancel();
MsgUtils.logAndShowErrorMessage(getActivity(), error);
}
});
req.setRetryPolicy(MyApplication.getDefaultRetryPolice());
req.setShouldCache(false);
MyApplication.getInstance().addToRequestQueue(req, "weather_requests");
}
/*
{"coord":{"lon":78.47,"lat":17.38},"weather":[{"id":802,"main":"Clouds","description":"scattered clouds","icon":"03d"}],
"base":"stations","main":{"temp":306.15,"pressure":1006,"humidity":63,"temp_min":306.15,"temp_max":306.15},
"visibility":6000,"wind":{"speed":4.1,"deg":280},"clouds":{"all":40},"dt":1498132800,
"sys":{"type":1,"id":7830,"message":0.0163,"country":"IN","sunrise":1498090389,"sunset":1498137799},
"id":1269843,"name":"Hyderabad","cod":200}
* */