Android-第一行代码CoolWeather案例实战
CoolWeather仿写
环境信息
AndroidStudio 3.2 JDK1.8 运行与Android7.1 （项目本身不需要申请权限）
准备工作
1 新建项目 需要添加的四个库（均是到目前为止最新的 库 添加到build.gradle ）
implementation 'com.squareup.okhttp3:okhttp:3.11.0'
implementation 'com.google.code.gson:gson:2.8.5'
implementation 'com.github.bumptech.glide:glide:4.8.0'
implementation 'org.litepal.android:core:2.0.0'2 申请和风天气的key http://www.heweather.com/
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项目编写
1 定义各种包和文件
2 编写dbsql 下的 省市县 实体类 并 配置 litepal库
3 设置 litepal.xml 映射文件 并编写 Util包下 网络请求 方法
4 Util包下新建Utility类 解析和保存网络获取的数据
（因为上面图片都可以看完代码，所以不再附上代码）
（这里的代码较多 ，图片显示不完全，所以下面会附上代码）
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"));
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);
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);
county.save();
}
return true;
} catch (JSONException e) {
e.printStackTrace();
}
}
return false;
}
}5 下面就开始 编写界面了 Choose_area.xml
6 使用碎片加载布局
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 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;
private TextView titleText;
private Button backButton;
private ListView listView;
private View view;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.choose_area, container, false);
initView();
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);
//需要写上这句话，来创建数据库，要不然会报空指针
Connector.getDatabase();
//列表监听器
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
//如果选择的是省
if (currentLevel == LEVEL_PROVINCE) {
selectedProvince = provinceList.get(position);
queryCities();
//如果选择的是市
} else if (currentLevel == LEVEL_CITY) {
selectedCity = cityList.get(position);
queryCounties();
}
}
});
//回退按钮监听器
backButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (currentLevel == LEVEL_COUNTY) {
queryCities();
} else if (currentLevel == LEVEL_CITY) {
queryProvinces();
}
}
});
//调用 下面的方法
queryProvinces();
}
// 查询全国所有的省，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 queryProvinces() {
//设置 显示标题为中国
titleText.setText("中国");
//设置回退按钮隐藏
backButton.setVisibility(View.GONE);
//查询 省实体类的数据
provinceList = LitePal.findAll(Province.class);
//判断是不是有数据 如果有
if (provinceList.size() > 0) {
//把要显示在listview的数据列表清空
dataList.clear();
//遍历省数据
for (Province province : provinceList) {
//把数据加到 要显示在listview的数据列表 上
dataList.add(province.getProvinceName());
}
//通知数据更新
adapter.notifyDataSetChanged();
//设置listview 默认选择第一个
listView.setSelection(0);
// flag 设置为省 为回退做flag
currentLevel = LEVEL_PROVINCE;
//如果没有数据
} else {
//去服务器获取数据
String address = "http://guolin.tech/api/china";
queryFromServier(address, "province");
}
}
//查询全国所有的市，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;
queryFromServier(address, "city");
}
}
// 查询全国所有的县，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 cityCode = selectedCity.getCityCode();
int provinceCode = selectedProvince.getProvinceCode();
String address = "http://guolin.tech/api/china/" + provinceCode + "/" + cityCode;
queryFromServier(address, "county");
}
}
// 根据传入的地址和类型 从服务器查询省市县信息数据
private void queryFromServier(String address, final String type) {
//显示对话框
showProgressDialog();
HttpUtil.sendOkHttpRequest(address, new Callback() {
@Override
public void onResponse(Call call, Response response) throws IOException {
//把获取到的数据设置为字符串
String responseText = response.body().string();
//设置结果
boolean result = false;
if ("province".equals(type)) {
//返回的省数据处理结果
result = Utility.handleProvinceResponse(responseText);
} else if ("city".equals(type)) {
//返回的市数据处理结果
result = Utility.handleCityResponse(responseText, selectedProvince.getId());
} else if ("county".equals(type)) {
//返回的县数据处理结果
result = Utility.handleCountyResponse(responseText, selectedCity.getId());
}
//根据返回的数据结果更新数据
if (result) {
//获取主线程（UI必须在主线程更新）
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();
}
}
});
}
}
@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_LONG).show();
}
});
}
});
}
private void showProgressDialog() {
if (progressDialog == null) {
progressDialog = new ProgressDialog(getActivity());
progressDialog.setMessage("正在加载...");
progressDialog.setCanceledOnTouchOutside(false);
}
progressDialog.show();
}
private void closeProgressDialog() {
if (progressDialog != null) {
progressDialog.dismiss();
}
}
private void initView() {
titleText = view.findViewById(R.id.title_text);
backButton = view.findViewById(R.id.back_button);
listView = view.findViewById(R.id.list_view);
}
} 7 在 activity_main.xml 加载碎片
8 现在就可以运行出现这样的结果
当然了 回退的图标需要自己找
9 既然选择城市的界面已经出来 那就应该点击县 进入天气界面
在上面的 ChooseAreaFragment 碎片中已经定义了 listview 的点击事件具体处理方法不过只有点击了 省和点击了市的 现在要添加点击了县的
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView parent, View view, int position, long id) {
//点击了省
if (currentLevel == LEVEL_PROVINCE) {
selectedProvince = provinceList.get(position);
queryCities();
//点击了市
} else if (currentLevel == LEVEL_CITY) {
selectedCity = cityList.get(position);
queryCounties();
}
//点击了县
else if (currentLevel == LEVEL_COUNTY) {
//获取县的实体类中的 WeatherId
String weatherId = countyList.get(position).getWeatherId();
//如果这是在 MainActivity 的xml布局中的碎片
if (getActivity() instanceof MainActivity) {
//用 Intent 传值 直接跳转到 WeatherActivity 活动
Intent intent = new Intent(getActivity(), WeatherActivity.class);
intent.putExtra("weather_id", weatherId);
startActivity(intent);
//关闭这个活动
getActivity().finish();
// 如果这是在 WeatherActivity的xml布局中的碎片 也就是抽屉布局中的
} else if (getActivity() instanceof WeatherActivity) {
//获得 活动实例
WeatherActivity activity = (WeatherActivity) getActivity();
//使用 SharedPreferences 把 weather_id 储存起来
SharedPreferences.Editor editor =PreferenceManager.getDefaultSharedPreferences(getContext()).edit();
editor.putString("weather_id", weatherId);
editor.apply();
//关闭抽屉
activity.drawerLayout.closeDrawers();
//显示刷新图标
activity.swipeRefresh.setRefreshing(true);
//请求天气（下面会有）
activity.requestWeather(weatherId);
}
}
}
});
10 编写天气界面 书上是 分步写的 ，所以新建文件比较多，嫌麻烦就写在一个里
这五个布局就不写了很简单
11 接下来就是 WeatherActivity.java
在此之前要定义一个工具方法 用来将返回的 JSON 数据 解析称实体类
然后再进行WeatherActivity.java
public class WeatherActivity extends AppCompatActivity {
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 backgroundImg;
public SwipeRefreshLayout swipeRefresh;public DrawerLayout drawerLayout;
private Button navButton;private Intent intent;
private String mWeatherId;
//设置沉浸式
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//沉浸模式
if (Build.VERSION.SDK_INT >= 21) {
View decorView = getWindow().getDecorView();
decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
| View.SYSTEM_UI_FLAG_LAYOUT_STABLE);
getWindow().setStatusBarColor(Color.TRANSPARENT);
}
setContentView(R.layout.activity_weather);
//调用初始化控件方法
initView();
}
//获取控件
private void initView() {
weatherLayout = findViewById(R.id.weather_layout);
titleCity = findViewById(R.id.title_city);
titleUpdateTime = findViewById(R.id.title_update_time);
degreeText = findViewById(R.id.degree_text);
weatherInfoText = findViewById(R.id.weather_info_text);
forecastLayout = findViewById(R.id.forecast_layout);
aqiText = findViewById(R.id.aqi_text);
pm25Text = findViewById(R.id.pm25_text);
comfortText = findViewById(R.id.comfort_text);
carWashText = findViewById(R.id.car_wash_text);
sportText = findViewById(R.id.sport_text);
backgroundImg = findViewById(R.id.background_img);
swipeRefresh = findViewById(R.id.swipe_refresh);
swipeRefresh.setColorSchemeResources(R.color.colorPrimary);
drawerLayout = findViewById(R.id.drawer_layout);
navButton = findViewById(R.id.nav_button);
navButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
drawerLayout.openDrawer(GravityCompat.START);
}
});
final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
String weatherString = prefs.getString("weather", null);
String bing_pic = prefs.getString("bing_pic", null);
if (bing_pic != null) {
Glide.with(this).load(bing_pic).into(backgroundImg);
} else {
loadBingPic();
}
if (weatherString != null) {
//有缓存时直接解析天气
Weather weather = Utility.handleWeatherResponse(weatherString);
mWeatherId = weather.basic.weatherId;
ShowWeatherInfo(weather);
} else {
//没有缓存信息去服务器查询信息
mWeatherId = getIntent().getStringExtra("weather_id");
weatherLayout.setVisibility(View.INVISIBLE);
requestWeather(mWeatherId);
}
swipeRefresh.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
String weather_id = prefs.getString("weather_id", null);
requestWeather(weather_id);
}
});
}
//加载每日一图
private void loadBingPic() {
String requestBinfPic = "http://guolin.tech/api/bing_pic";
HttpUtil.sendOkHttpRequest(requestBinfPic, new Callback() {
@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(backgroundImg);
}
});
}
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
});
}
//根据天气 ID 请求城市天气
public void requestWeather(final String weatherId) {
String weatherUrl = "http://guolin.tech/api/weather?cityid=" + weatherId +
"&key=d4892ac004c84b498d27455a89623852";
// http://guolin.tech/api/weather?cityid=CN101080507&key=d4892ac004c84b498d27455a89623852
HttpUtil.sendOkHttpRequest(weatherUrl, new Callback() {
@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();
ShowWeatherInfo(weather);
} else {
Toast.makeText(WeatherActivity.this, "获取天气信息失败"
, Toast.LENGTH_SHORT).show();
}
swipeRefresh.setRefreshing(false);
}
});
}
@Override
public void onFailure(Call call, IOException e) {
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);
}
});
}
});
}
// 处理并显示Weather 实体类中的数据
private void ShowWeatherInfo(Weather weather) {
if (weather != null && "ok".equals(weather.status)) {
String cityName = weather.basic.cityName;
String upadteTime = weather.basic.update.updateTime.split(" ")[1];
String degrss = weather.now.temperature + "℃";
String weatherinfo = weather.now.more.info;
titleCity.setText(cityName);
titleUpdateTime.setText(upadteTime);
degreeText.setText(degrss);
weatherInfoText.setText(weatherinfo);
forecastLayout.removeAllViews();
for (Forecast forecast : weather.forecastList) {
View view = LayoutInflater.from(this).inflate(R.layout.forecast_item, forecastLayout, false);
TextView dateText = view.findViewById(R.id.date_text);
TextView infoText = view.findViewById(R.id.info_text);
TextView maxText = view.findViewById(R.id.max_text);
TextView minText = view.findViewById(R.id.min_text);
dateText.setText(forecast.date);
infoText.setText(forecast.more.info);
maxText.setText(forecast.temperature.max);
minText.setText(forecast.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 ：\n" + weather.suggestion.comfort.info;
String carwach = "洗车指数：\n" + weather.suggestion.carWash.info;
String sport = "运动建议：\n" + weather.suggestion.sport.info;
comfortText.setText(comfort);
carWashText.setText(carwach);
sportText.setText(sport);
weatherLayout.setVisibility(View.VISIBLE);
intent = new Intent(this, AutoUpdateService.class);
startService(intent);
} else {
Toast.makeText(WeatherActivity.this, "获取天气信息失败"
, Toast.LENGTH_SHORT).show();
}
}
@Override
protected void onPause() {
super.onPause();
stopService(intent);
}
}
12 在Service包下 新建 Service
public class AutoUpdateService extends Service {
@Override
public IBinder onBind(Intent intent) {
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
updateWeather();
updateBingPic();
AlarmManager manager = (AlarmManager) getSystemService(ALARM_SERVICE);
int anHOur = 3*60 * 1000;
long triggerAtTime = SystemClock.elapsedRealtime() + anHOur;
Intent i = new Intent(this, AutoUpdateService.class);
PendingIntent pi = PendingIntent.getService(this, 0, i, 0);
manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtTime, pi);
manager.cancel(pi);
return super.onStartCommand(intent, flags, startId);
}
//更新每日一图 保存到 SharedPreferences
private void updateBingPic() {
String requestBinfPic = "http://guolin.tech/api/bing_pic";
HttpUtil.sendOkHttpRequest(requestBinfPic, new Callback() {
@Override
public void onResponse(Call call, Response response) throws IOException {
final String bingpic = response.body().string();
SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(AutoUpdateService.this).edit();
editor.putString("bing_pic", bingpic);
editor.apply();
}
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
});
}
//更新天气 保存到SharedPreferences
private void updateWeather() {
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);
String weatherId = weather.basic.weatherId;
String weatherUrl = "http://guolin.tech/api/weather?cityid=" + weatherId +
"&key=d4892ac004c84b498d27455a89623852";
HttpUtil.sendOkHttpRequest(weatherUrl, new Callback() {
@Override
public void onResponse(Call call, Response response) throws IOException {
String responseText = response.body().string();
Weather weather = Utility.handleWeatherResponse(responseText);
if (weather != null && "ok".equals(weather.status)) {
SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(AutoUpdateService.this).edit();
editor.putString("weather", responseText);
editor.apply();
}
}
@Override
public void onFailure(Call call, IOException e) {
e.printStackTrace();
}
});
}
}
}但是每次运行都会出现省市县的选择 所以需要设置 MainActivity.java
这样 基本项目就完成了
还可以做的事
可以 在Service 中 放 Notification 让数据实时显示到状态栏
增加 设置界面 是否显示 Notification
增加一个 悬浮按钮 显示 选择过的县 不用再来回切换县
。。。