先要建议三张表：province、city、county，分别用于存放省市县的数据信息。

Province.java

package com.example.lenovo.coolweather.db;

import org.litepal.crud.DataSupport;

/**
 * 代表省的数据库表
 */

public class Province extends DataSupport {
    private int id;    //id号
    private String provinceName;  //省得名字
    private int provinceCode;    //省得代号

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getProvinceName() {
        return provinceName;
    }

    public void setProvinceName(String provinceName) {
        this.provinceName = provinceName;
    }

    public int getProvinceCode() {
        return provinceCode;
    }

    public void setProvinceCode(int provinceCode) {
        this.provinceCode = provinceCode;
    }
}

City.java

package com.example.lenovo.coolweather.db;

import org.litepal.crud.DataSupport;

/**
 * 代表市的数据库表
 */

public class City extends DataSupport {
    private int id;
    private String cityName;  //城市名字
    private int cityCode;   //城市代号
    private int provinceId;   //当前城市所属省得id

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCityName() {
        return cityName;
    }

    public void setCityName(String cityName) {
        this.cityName = cityName;
    }

    public int getCityCode() {
        return cityCode;
    }

    public void setCityCode(int cityCode) {
        this.cityCode = cityCode;
    }

    public int getProvinceId() {
        return provinceId;
    }

    public void setProvinceId(int provinceId) {
        this.provinceId = provinceId;
    }
}

package com.example.lenovo.coolweather.db;

import org.litepal.crud.DataSupport;

/**
 * 代表县的数据库表
 */

public class County extends DataSupport {
    private int id;
    private String countName;  //县的名字
    private String weatherId;   //天气id
    private int cityId;    //当前县所属城市的id

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getCountName() {
        return countName;
    }

    public void setCountName(String countName) {
        this.countName = countName;
    }

    public String getWeatherId() {
        return weatherId;
    }

    public void setWeatherId(String weatherId) {
        this.weatherId = weatherId;
    }

    public int getCityId() {
        return cityId;
    }

    public void setCityId(int cityId) {
        this.cityId = cityId;
    }
}

ChooseAreaFragment.java

package com.example.lenovo.coolweather;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.lenovo.coolweather.db.City;
import com.example.lenovo.coolweather.db.County;
import com.example.lenovo.coolweather.db.Province;
import com.example.lenovo.coolweather.util.HttpUtil;
import com.example.lenovo.coolweather.util.Utility;

import org.litepal.crud.DataSupport;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.Response;

/**
 * 遍历省市县数据的碎片
 */

public class ChooseAreaFragment extends Fragment {
    public static final int LEVEL_PROVINCE = 0;   //省标记
    public static final int LEVEL_CITY = 1;    //市标记
    public static final int LEVEL_COUNTY = 2;   //县标记
    private ProgressDialog progressDialog;   //进度条
    private TextView titleText;       //标题
    private Button backButton;       //返回按钮
    private ListView listView;
    private ArrayAdapter<String> adapter;
    private List<String> dataList = new ArrayList<>();

    private List<Province> provinceList;   //省列表
    private List<City> cityList;  //市列表
    private List<County> countyList;  //县列表

    private Province selectProvince;  //选中的省份
    private City selectCity;  //选中的城市
    private int currentLevel;  //当前选中的级别

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.choose_area, container, false);
        //找到控件
        titleText = (TextView) view.findViewById(R.id.title_text);
        backButton = (Button) view.findViewById(R.id.back_button);
        listView = (ListView) view.findViewById(R.id.list_view);
        //创建适配器
        adapter = new ArrayAdapter<String>(getContext(),
                android.R.layout.simple_list_item_1, dataList);
        //设置适配器
        listView.setAdapter(adapter);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        //设置监听
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                if (currentLevel == LEVEL_PROVINCE) {
                    selectProvince = provinceList.get(position);
                    queryCities();
                } else if (currentLevel == LEVEL_CITY) {
                    selectCity = cityList.get(position);
                    queryCounties();
                }else if(currentLevel == LEVEL_COUNTY){
                    //跳转到天气界面
                    String weatherId = countyList.get(position).getWeatherId();
                    if(getActivity() instanceof MainActivity){
                        Intent intent = new Intent(getActivity(),WeatherActivity.class);
                        intent.putExtra("weather_id",weatherId);
                        startActivity(intent);
                        getActivity().finish();
                    }else if(getActivity() instanceof WeatherActivity){
                        WeatherActivity activity = (WeatherActivity) getActivity();
                        activity.drawerLayout.closeDrawers();
                        activity.swipeRefresh.setRefreshing(true);
                        activity.requestWeather(weatherId);
                    }

                }
            }
        });
        //设置按钮监听事件
        backButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (currentLevel == LEVEL_COUNTY) {
                    queryCities();
                } else if (currentLevel == LEVEL_CITY) {
                    queryProvince();
                }
            }
        });
        queryProvince();
    }

    /**
     * 查询所有的省，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 queryProvince() {
        titleText.setText("中国");
        //隐藏返回按钮
        backButton.setVisibility(View.GONE);
        //先从数据库中查找数据
        provinceList = DataSupport.findAll(Province.class);
        //大于0，说明数据库中有数据
        if (provinceList.size() > 0) {
            //重新设置适配器，更新数据
            dataList.clear();
            for (Province province : provinceList) {
                dataList.add(province.getProvinceName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            currentLevel = LEVEL_PROVINCE;
        } else {
            //数据库中没有数据，从网络中获取
            String address = "http://guolin.tech/api/china";
            queryFromServer(address, "province");
        }
    }

    /**
     * 查询选中省中的所有的市，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(selectProvince.getProvinceName());
        backButton.setVisibility(View.VISIBLE);
        cityList = DataSupport.where("provinceid = ?", String.valueOf(selectProvince.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 = selectProvince.getProvinceCode();
            String address = "http://guolin.tech/api/china/" + provinceCode;
            queryFromServer(address, "city");
        }
    }

    /**
     * 查询选中市中的所有的县，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(selectCity.getCityName());
        backButton.setVisibility(View.VISIBLE);
        countyList = DataSupport.where("cityid=?", String.valueOf(selectCity.getId())).find(County.class);
        if (countyList.size() > 0) {
            dataList.clear();
            for (County county : countyList) {
                dataList.add(county.getCountName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            currentLevel = LEVEL_COUNTY;
        } else {
            int provinceCode = selectProvince.getProvinceCode();
            int cityCode = selectCity.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
     *
     * @param address
     * @param type
     */
    private void queryFromServer(String address, final String type) {
        showProgressDialog();
        HttpUtil.sendOkHttpRequest(address, new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                getActivity().runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        closeProgressDialog();
                        Toast.makeText(getContext(), "加载失败", Toast.LENGTH_SHORT).show();
                    }
                });
            }

            @Override
            public void onResponse(Call call, 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,
                            selectProvince.getId());
                } else if ("county".equals(type)) {
                    result = Utility.handleCountyResponse(responseText,
                            selectCity.getId());
                }
                if (result) {
                    getActivity().runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            closeProgressDialog();
                            if ("porvince".equals(type)) {
                                queryProvince();
                            } else if ("city".equals(type)) {
                                queryCities();
                            } else if ("county".equals(type)) {
                                queryCounties();
                            }
                        }
                    });
                }
            }
        });
    }

    /**
     * 显示进度条
     */

    private void showProgressDialog() {
        if (progressDialog == null) {
            progressDialog = new ProgressDialog(getActivity());
            progressDialog.setMessage("加载中...");
            progressDialog.setCanceledOnTouchOutside(false);
        }
        progressDialog.show();
    }

    /**
     * 关闭进度条
     */
    private void closeProgressDialog() {
        if (progressDialog != null) {
            progressDialog.dismiss();
        }
    }

}

WeatherActicity.java

package com.example.lenovo.coolweather;

import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.os.Build;
import android.preference.PreferenceManager;
import android.support.v4.content.SharedPreferencesCompat;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ScrollView;
import android.widget.TextView;
import android.widget.Toast;

import com.bumptech.glide.Glide;
import com.example.lenovo.coolweather.gson.Forcast;
import com.example.lenovo.coolweather.gson.Weather;
import com.example.lenovo.coolweather.service.AutoUpdateService;
import com.example.lenovo.coolweather.util.HttpUtil;
import com.example.lenovo.coolweather.util.Utility;

import java.io.IOException;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.Response;

public class WeatherActivity extends AppCompatActivity {
    public SwipeRefreshLayout swipeRefresh;
    public DrawerLayout drawerLayout;
    private Button navButton;
    private String mWeatherId;
    private ScrollView weatherLayout;
    private TextView titleCity;
    private TextView titleUpdateTime;
    private TextView degreeText;
    private TextView weatherInfoText;
    private LinearLayout forecastLayout;
    private TextView aqiText;
    private TextView pm25Text;
    private TextView comfortText;
    private TextView carWashText;
    private TextView sportText;
    private ImageView bingPicImg;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if(Build.VERSION.SDK_INT >= 21){
            //拿到当前活动的DecorView
            View decorView = getWindow().getDecorView();
            //活动的布局显示在状态栏上面
            decorView.setSystemUiVisibility(
                    View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
            getWindow().setStatusBarColor(Color.TRANSPARENT);
        }
        setContentView(R.layout.activity_weather);
        //初始化各控件
        initView();
        swipeRefresh.setColorSchemeResources(R.color.colorPrimary);
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        String weatherString = prefs.getString("weather",null);
        if(weatherString != null){
            //有缓存时直接解析天气数据
            Weather weather = Utility.handleWeatherResponse(weatherString);
            mWeatherId = weather.basic.weatherId;
            showWeatherInfo(weather);
        }else{
            //没有缓存时去服务器查询天气
            //String weatherId = getIntent().getStringExtra("weather_id");
            mWeatherId = getIntent().getStringExtra("weather_id");;
            weatherLayout.setVisibility(View.INVISIBLE);
            requestWeather(mWeatherId);
        }

        swipeRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                requestWeather(mWeatherId);
            }
        });

        String bingPic = prefs.getString("bing_pic",null);
        if(bingPic != null){
            Glide.with(this).load(bingPic).into(bingPicImg);
        }else{
            loadBingPic();
        }
        navButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                drawerLayout.openDrawer(GravityCompat.START);
            }
        });

    }

    /**
     * 找到所有控件
     */

    private void initView() {
        drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
        navButton = (Button) findViewById(R.id.nav_button);
        swipeRefresh = (SwipeRefreshLayout) findViewById(R.id.swipe_regresh);
        bingPicImg = (ImageView) findViewById(R.id.bing_pic_img);
        weatherLayout = (ScrollView) findViewById(R.id.weather_layout);
        titleCity = (TextView) findViewById(R.id.title_city);
        titleUpdateTime = (TextView) findViewById(R.id.title_update_time);
        degreeText = (TextView) findViewById(R.id.degree_text);
        weatherInfoText = (TextView) findViewById(R.id.weather_info_text);
        forecastLayout = (LinearLayout) findViewById(R.id.forecast_layout);
        aqiText = (TextView) findViewById(R.id.aqi_text);
        pm25Text = (TextView) findViewById(R.id.pm25_text);
        comfortText  = (TextView) findViewById(R.id.comfort_text);
        carWashText = (TextView) findViewById(R.id.car_wash_text);
        sportText = (TextView) findViewById(R.id.sport_text);
    }

    /**
     * 加载必应每日一图
     */
    private void loadBingPic() {
        String requestBingPic = "http://guolin.tech/api/bing_pic";
        HttpUtil.sendOkHttpRequest(requestBingPic, new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                final String bingPic = response.body().string();
                SharedPreferences.Editor editor = PreferenceManager
                        .getDefaultSharedPreferences(WeatherActivity.this).edit();
                editor.putString("bing_pic",bingPic);
                editor.apply();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Glide.with(WeatherActivity.this).load(bingPic).into(bingPicImg);
                    }
                });
            }
        });
    }

    /**
     * 根据天气id请求城市天气信息
     * @param weatherId
     */
    public void requestWeather(String weatherId) {
        String weatherUrl = "http://guolin.tech/api/weather?cityid=" +weatherId+
                "&key=bc0418b57b2d4918819d3974ac1285d9";
        HttpUtil.sendOkHttpRequest(weatherUrl, new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                e.printStackTrace();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(WeatherActivity.this,"获取天气信息失败",Toast.LENGTH_SHORT).show();
                        swipeRefresh.setRefreshing(false);
                    }
                });
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                final String responseText = response.body().string();
                final Weather weather = Utility.handleWeatherResponse(responseText);
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        if(weather != null && "ok".equals(weather.status)){
                            SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(WeatherActivity.this)
                                    .edit();
                            editor.putString("weather",responseText);
                            editor.apply();
                            Intent intent = new Intent(WeatherActivity.this, AutoUpdateService.class);
                            startService(intent);
                            showWeatherInfo(weather);
                        }else{
                            Toast.makeText(WeatherActivity.this,"获取天气信息失败",Toast.LENGTH_SHORT).show();
                        }
                        swipeRefresh.setRefreshing(false);
                    }
                });

            }
        });
        loadBingPic();

    }

    /**
     * 处理并展示Weather实体类的数据
     * @param weather
     */
    private void showWeatherInfo(Weather weather) {
        String cityName = weather.basic.cityName;
        String updateTime = weather.basic.update.updateTime.split(" ")[1];
        String degree = weather.now.temperature+"℃";
        String weatherInfo = weather.now.more.info;
        titleCity.setText(cityName);
        titleUpdateTime.setText(updateTime);
        degreeText.setText(degree);
        weatherInfoText.setText(weatherInfo);
        forecastLayout.removeAllViews();
        for(Forcast forcast : weather.forcastList){
            View view = LayoutInflater.from(this).inflate(R.layout.forecast_item,forecastLayout,false);
            TextView dateText = (TextView) view.findViewById(R.id.date_text);
            TextView infoText = (TextView) view.findViewById(R.id.info_text);
            TextView maxText = (TextView) view.findViewById(R.id.max_text);
            TextView minText = (TextView) view.findViewById(R.id.min_text);
            dateText.setText(forcast.date);
            infoText.setText(forcast.more.info);
            maxText.setText(forcast.temperature.max);
            minText.setText(forcast.temperature.min);
            forecastLayout.addView(view);
        }
        if(weather.aqi != null){
            aqiText.setText(weather.aqi.city.aqi);
            pm25Text.setText(weather.aqi.city.pm25);
        }
        String comfort = "舒适度："+weather.suggestion.comfort.info;
        String carWash = "洗车指数："+weather.suggestion.carWash.info;
        String sport = "运动建议："+weather.suggestion.sport.info;
        comfortText.setText(comfort);
        carWashText.setText(carWash);
        sportText.setText(sport);
        weatherLayout.setVisibility(View.VISIBLE);

    }
}

package com.example.lenovo.coolweather;

import android.content.Intent;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        if(prefs.getString("weather",null) != null){
            Intent intent = new Intent(this,WeatherActivity.class);
            startActivity(intent);
            finish();
        }
    }
}

完整项目在：https://github.com/zhaoqingliang/MyCoolWeather.git点击打开链接