Android——天气预报（酷欧天气）（第二篇）
16lz
2021-12-04
**接着上一篇**功能：传入请求地址，并注册一个回调来处理服务器响应
public class HttpUtil { public static void sendOkHttpRequest(String address, okhttp3.Callback callback) { //OkHttpClient client = new OkHttpClient(); //传入请求地址 Request request = new Request.Builder().url(address).build(); OkHttpClient client = new OkHttpClient().newBuilder().connectTimeout(60000, TimeUnit.MILLISECONDS) .readTimeout(60000, TimeUnit.MILLISECONDS) .build(); //注册一个回调来处理服务器响应 client.newCall(request).enqueue(callback); }}然后在包内继续建立一个名为Utility的类
分别用于处理来自服务器的省市县三级的数据
public class Utility { /** * 解析和处理服务器返回的省级数据 */ public static boolean handleProvinceResponse(String response) { if(!TextUtils.isEmpty(response)) { try { JSONArray allProvinces = new JSONArray(response); for (int i = 0; i < allProvinces.length(); i++) { JSONObject provinceObject = allProvinces.getJSONObject(i); Province province = new Province(); province.setProvinceName(provinceObject.getString("name")); province.setProvinceCode(provinceObject.getInt("id")); //调用save()方法将数据存储到数据库中 province.save(); } return true; }catch (JSONException e) { e.printStackTrace(); } } return false; } /** * 解析和处理服务器返回的市级数据 */ public static boolean handleCityResponse(String response, int provinceId) { if(!TextUtils.isEmpty(response)) { try { JSONArray allCities = new JSONArray(response); for (int i = 0; i < allCities.length(); i++) { JSONObject cityObject = allCities.getJSONObject(i); City city = new City(); city.setCityName(cityObject.getString("name")); city.setCityCode(cityObject.getInt("id")); city.setProvinceId(provinceId); //调用save()方法将数据存储到数据库中 city.save(); } return true; }catch (JSONException e) { e.printStackTrace(); } } return false; } /** * 解析和处理服务器返回的县级数据 */ public static boolean handleCountyResponse(String response, int cityId) { if(!TextUtils.isEmpty(response)) { try { JSONArray allCounties = new JSONArray(response); for (int i = 0; i < allCounties.length(); i++) { JSONObject countyObject = allCounties.getJSONObject(i); County county = new County(); county.setCountyName(countyObject.getString("name")); county.setWeatherId(countyObject.getString("weather_id")); county.setCityId(cityId); //调用save()方法将数据存储到数据库中 county.save(); } return true; }catch (JSONException e) { e.printStackTrace(); } } return false; } /** * 将返回的JSON数据解析成Weather实体类 */ public static Weather handleWeatherResponse(String response) { try { JSONObject jsonObject = new JSONObject(response); JSONArray jsonArray = jsonObject.getJSONArray("HeWeather"); String weatherContent = jsonArray.getJSONObject(0).toString(); return new Gson().fromJson(weatherContent,Weather.class); }catch (Exception e) { e.printStackTrace(); } return null; }}接下来我们建立一个名为choose_area的布局文件，用于存放标题，返回键，还有省市县列表
back图片是我们事先准备好的
代码如下：
效果如下：
然后写一个遍历省市县三级的碎片类
名为：ChooseAreaFragment继承于Fragment
代码如下：
public class ChooseAreaFragment extends Fragment { public static final int LEVEL_PROVINCE = 0; public static final int LEVEL_CITY = 1; public static final int LEVEL_COUNTY = 2; private ProgressDialog progressDialog; private TextView titleText; private Button backButton; private ListView listView; private ArrayAdapter adapter; private List dataList = new ArrayList<>(); /** * 省列表 */ private List provinceList; /** * 市列表 */ private List cityList; /** * 县列表 */ private List countyList; /** * 选中的省份 */ private Province selectedProvince; /** * 选中的城市 */ private City selectedCity; /** * 当前选中的级别 */ private int currentLevel; @Nullable @Override public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View view = inflater.inflate(R.layout.choose_area, container, false); titleText = (TextView) view.findViewById(R.id.title_text); backButton = (Button)view.findViewById(R.id.back_button); listView = (ListView) view.findViewById(R.id.list_view); adapter = new ArrayAdapter<>(getContext(),android.R.layout.simple_list_item_1, dataList); listView.setAdapter(adapter); return view; } @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if(currentLevel == LEVEL_PROVINCE) { selectedProvince = provinceList.get(position); queryCities(); } else if (currentLevel == LEVEL_CITY) { selectedCity = cityList.get(position); queryCounties(); } else if(currentLevel == LEVEL_COUNTY) { String weatherId = countyList.get(position).getWeatherId(); if(getActivity() instanceof MainActivity) { Intent intent = new Intent(getActivity(), WeatherActivty.class); intent.putExtra("weather_id",weatherId); startActivity(intent); getActivity().finish(); } else if(getActivity() instanceof WeatherActivty) { WeatherActivty activity = (WeatherActivty)getActivity(); activity.drawerLayout.closeDrawers(); activity.swipeRefresh.setRefreshing(true); activity.requestWeather(weatherId); } } } }); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if(currentLevel == LEVEL_COUNTY) { queryCities(); } else if (currentLevel == LEVEL_CITY) { queryProvinces(); } } }); queryProvinces(); } private void queryProvinces() { titleText.setText("中国"); backButton.setVisibility(View.GONE); provinceList = LitePal.findAll(Province.class); if(provinceList.size() > 0) { dataList.clear(); for (Province province:provinceList) { dataList.add(province.getProvinceName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_PROVINCE; } else { String address = "http://guolin.tech/api/china"; queryFromServer(address,"province"); } } /** * 查询选中省内所有的市，优先从数据库查询，如果没有查询到再去服务器上查询 */ private void queryCities() { titleText.setText(selectedProvince.getProvinceName()); backButton.setVisibility(View.VISIBLE); cityList = LitePal.where("provinceid = ?", String.valueOf(selectedProvince.getId())).find(City.class); if(cityList.size() > 0) { dataList.clear(); for (City city: cityList) { dataList.add(city.getCityName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_CITY; } else { int provinceCode = selectedProvince.getProvinceCode(); String address = "http://guolin.tech/api/china/" + provinceCode; queryFromServer(address,"city"); } } /** * 查询选中市内所有的县，优先从数据库查询，如果没有查询到再去服务器上查询 */ private void queryCounties() { titleText.setText(selectedCity.getCityName()); backButton.setVisibility(View.VISIBLE); countyList = LitePal.where("cityid = ?", String.valueOf(selectedCity.getId())).find(County.class); if(countyList.size() > 0) { dataList.clear(); for (County county: countyList) { dataList.add(county.getCountyName()); } adapter.notifyDataSetChanged(); listView.setSelection(0); currentLevel = LEVEL_COUNTY; } else { int provinceCode = selectedProvince.getProvinceCode(); int cityCode = selectedCity.getCityCode(); String address = "http://guolin.tech/api/china/" + provinceCode + "/" + cityCode; queryFromServer(address,"county"); } } /** * 根据传入的地址和类型从服务器上查询省市县数据 */ private void queryFromServer(String address, final String type) { showProgressDialog(); HttpUtil.sendOkHttpRequest(address, new Callback() { @Override public void onFailure(@NotNull Call call, @NotNull IOException e) { //通过runOnUiThread()方法回到主线程逻辑 getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); Toast.makeText(getContext(),"加载失败",Toast.LENGTH_SHORT).show(); } }); } @Override public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException { String responseText = response.body().string(); boolean result = false; if("province".equals(type)) { result = Utility.handleProvinceResponse(responseText); } else if("city".equals(type)) { result = Utility.handleCityResponse(responseText,selectedProvince.getId()); } else if("county".equals(type)) { result = Utility.handleCountyResponse(responseText,selectedCity.getId()); } if (result) { getActivity().runOnUiThread(new Runnable() { @Override public void run() { closeProgressDialog(); if("province".equals(type)) { queryProvinces(); } else if ("city".equals(type)) { queryCities(); } else if ("county".equals(type)) { queryCounties(); } } }); } } }); } /** * 显示进度对话框 */ private void showProgressDialog() { if(progressDialog == null) { progressDialog = new ProgressDialog(getActivity()); progressDialog.setMessage("正在加载···"); progressDialog.setCanceledOnTouchOutside(false); } progressDialog.show(); } /** * 关闭进度对话框 */ private void closeProgressDialog() { if(progressDialog != null) { progressDialog.dismiss(); } }} 然后我们在activity_main.xml显示碎片
代码如下：
最后我们在清单文件中声明网罗权限
到这里第二篇结束了，我们已经可以查看所有的省市县三级列表了
效果图如下：
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