[大数据]天气预报app

一、在Java代码中初始化界面

在MainActivity中初始化ViewPager界面

    private void initPager() {
        //创建Fragment对象添加到ViewPager数据源当中
        for (int i=0;i<cityList.size();i++){  //使用for循环将城市集合中的内容添加到fragment集合中
            WeatherFragment weatherFragment = new WeatherFragment(); 
            Bundle bundle = new Bundle();    
            bundle.putString("city",cityList.get(i));  //使用bundle存储城市名，传到fragment中
            weatherFragment.setArguments(bundle);
            fragmentList.add(weatherFragment);
        }
        //将fragment集合传入fragment适配器中
                FragmentPagerAdapter fragmentPagerAdapter = new FragmentPagerAdapter(getSupportFragmentManager(),fragmentList);
        showVp.setAdapter(fragmentPagerAdapter);
    }

在WeatherFragment中获取从MainActivity中传入的城市

//通过activity传值获取到当前fragment加载的是哪个地方的天气情况
Bundle arguments = getArguments();
String city=arguments.getString("city");
getWeatherCity(city);

编写FragmentPagerAdapter用于fragment的显示

public class FragmentPagerAdapter extends FragmentStatePagerAdapter {
    List<Fragment> fragmentList;  //主界面传入的fragmenr的集合
    public FragmentPagerAdapter(FragmentManager fragmentManager,List<Fragment> fragments) {
        super(fragmentManager);
        this.fragmentList=fragments;
    }
    @NonNull
    @Override
    public Fragment getItem(int position) {  //根据位置获取集合条目内容
        return fragmentList.get(position);
    }

    @Override
    public int getCount() {   //获取集合条目个数
        return fragmentList.size();
    }
}

二、子线程中开启网络请求

编写NetUtil类，在类中编写两个静态方法doGet和getWeatherOfCity

doGet方法用于从网络中获取数据，getWeatherOfCity方法用于拼接url之后，调用doGet方法传入url获取天气信息

    public static final String URL_WEATHER="https://tianqiapi.com/api?unescape=1&version=v1&appid=22444194&appsecret=EG7XHDop";
    public static String doGet(String urlString){
        String result="";
        String line;
        StringBuilder stringBuilder=null;
        BufferedReader bufferedReader=null;
        //连接网络
        HttpURLConnection connection=null;
        InputStreamReader isr=null;
        try {
            URL url=new URL(urlString);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");  //链接方式
            connection.setConnectTimeout(5000);   //超时时间
            //从连接中读取数据(二进制)
            InputStream inputStream=connection.getInputStream();
            //对数据流进行加工
            isr=new InputStreamReader(inputStream);
            //创建缓冲区，将二进制流送入
            bufferedReader=new BufferedReader(isr);
            //从缓冲区一行一行读取字符串
            stringBuilder=new StringBuilder();
            while ((line=bufferedReader.readLine())!=null){
                stringBuilder.append(line); //进行拼接
            }
            result=stringBuilder.toString();
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            try {
                //关闭流
                connection.disconnect();
                bufferedReader.close();
                isr.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }
    //拼接出来获取天气的url
    public static String getWeatherOfCity(String city){
        String url=URL_WEATHER+"&city="+city;
        Log.i("Aye","URL:"+url);
        Log.i("Aye","URLResult:"+doGet(url));
        return  doGet(url);
    }

编写getWeatherCity方法，开启子线程，调用NetUtil类中的静态方法getWeatherOfCity来获取天气数据，并通过handler将数据传递给主线程

private void getWeatherCity(String selectCity) {
    //开启子线程，请求网络
    new Thread(new Runnable() {
        @Override
        public void run() {
            //请求网络
            String weatherOfCity=NetUtil.getWeatherOfCity(selectCity);
            //使用handler将数据传递给主线程
            Message message=Message.obtain();
            message.what=0;
            message.obj=weatherOfCity;
            handler.sendMessage(message);
        }
    }).start();
}

三、网络请求返回Json数据解析

使用在线工具解析Json数据并生成JavaBean导入包中

[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-zEJn14mR-1632214033044)(C:\Users\paranoia\AppData\Roaming\Typora\typora-user-images\image-20210915094807564.png)]

接收子线程传递的数据并使用gson解析

    private Handler handler=new Handler(Looper.myLooper()){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            if (msg.what==0){
                //主线程收到的天气数据
                String weather= (String) msg.obj;
                Log.i("Aye","主线程收到的天气数据："+weather);
                //使用gson解析
                Gson gson=new Gson();
                JsonRootBean jsonRootBean=gson.fromJson(weather, JsonRootBean.class);
               updateWeather(jsonRootBean); //更新天气数据并显示
            }
        }
    };

四、界面呈现

1. 获取天气数据并展示

编写updateWeather方法，用于获取数据并显示在界面上

    //数据显示
    private void updateWeather(JsonRootBean jsonRootBean) {
        if (jsonRootBean!=null){
            List<Data> dayWeather = jsonRootBean.getData(); //获取每一天的数据
            Data todayWeather = dayWeather.get(0);//获取今天的数据
            //不为空则显示今天天气数据
            if (todayWeather!=null){
                tempTv.setText(todayWeather.getTem1());
                mainWeatherTv.setText(todayWeather.getWea());;
                todayTv.setText("今天："+todayWeather.getWea());
                todayAirTv.setText("空气："+todayWeather.getAir_level());
                todayTempTv.setText(todayWeather.getTem()+"~"+todayWeather.getTem2());
                todayIconIv.setImageResource(getImg(todayWeather.getWea_img()));
                windTv.setText(todayWeather.getWin_speed());
                humidityTv.setText(todayWeather.getHumidity());
                pressureTv.setText(todayWeather.getPressure()+"hPa");
                windTv1.setText(todayWeather.getWin().get(0));
                sunriseTv.setText("日出："+todayWeather.getSunrise());
                sunsetTv.setText("日落："+todayWeather.getSunset());
            }
            //获取明天的数据
            Data tomorrowWeather = dayWeather.get(1);
            //不为空则显示明天数据
            if (tomorrowWeather!=null){
                tomorrowTv.setText("明天："+tomorrowWeather.getWea());
                tomorrowAirTv.setText("空气："+tomorrowWeather.getAir_level());
                tomorrowTempTv.setText(tomorrowWeather.getTem()+"~"+tomorrowWeather.getTem2());
                tomorrowIconIv.setImageResource(getImg(tomorrowWeather.getWea_img()));
            }
            //获取后天的数据
            Data afterWeather = dayWeather.get(2);
            //不为空则显示后天天气数据
            if (afterWeather!=null){
                afterTv.setText("后天："+afterWeather.getWea());
                afterAirTv.setText("空气："+afterWeather.getAir_level());
                afterTempTv.setText(afterWeather.getTem()+"~"+afterWeather.getTem2());
                afterIconIv.setImageResource(getImg(afterWeather.getWea_img()));
            }
            //获取指数信息
            List<Index> index = todayWeather.getIndex();
            //不为空则显示
            if (index!=null) {
                //紫外线指数
                UVTitle = index.get(0).getTitle();
                UVLevel = index.get(0).getLevel();
                UVDesc = index.get(0).getDesc();
                //穿衣指数
                clotheTitle = index.get(3).getTitle();
                clotheLevel = index.get(3).getLevel();
                clotheDesc = index.get(3).getDesc();
                //运动指数
                sportTitle=index.get(1).getTitle();
                sportLevel=index.get(1).getLevel();
                sportDesc=index.get(1).getDesc();
                //洗车指数
                carTitle=index.get(4).getTitle();
                carLevel=index.get(4).getLevel();
                carDesc=index.get(4).getDesc();
                //血糖指数
                sickTitle=index.get(2).getTitle();
                sickLevel=index.get(2).getLevel();
                sickDesc=index.get(2).getDesc();
                //空气污染指数
                airTitle=index.get(5).getTitle();
                airLevel=index.get(5).getLevel();
                airDesc=index.get(5).getDesc();
            }
            //获取逐小时天气情况，传递给Adapter用于显示
            List<Hours> timeBean = todayWeather.getHours();
            weatherAdapter=new WeatherAdapter(getActivity(),timeBean);
            LinearLayoutManager manager=new LinearLayoutManager(getActivity(), RecyclerView.HORIZONTAL,false);
            hoursRv.setAdapter(weatherAdapter);
            hoursRv.setLayoutManager(manager);
        }
    }

2. 根据天气情况显示对应图片

编写getImg方法用于根据天气情况显示图片

    private int getImg(String wea_img) {
        int result = 0;
        switch (wea_img) {
            case "qing": //晴天
                result=R.mipmap.sun;
                break;
            case "yin":  //阴天
                result=R.mipmap.yin;
                break;
            case "yu":  //雨天
                result=R.mipmap.yu;
                break;
            case "yun":    //多云
                result=R.mipmap.yun;
                break;
            case "bingbao":   //冰雹
                result=R.mipmap.bingbao;
                break;
            case "wu":   //雾
                result=R.mipmap.wu;
                break;
            case "shachen":  //沙尘暴
                result=R.mipmap.shachen;
                break;
            case "lei":    //雷
                result=R.mipmap.lei;
                break;
            case "xue":  //雪
                result=R.mipmap.xue;
                break;
            default:  //如果都不是则显示晴
                result=R.mipmap.sun;
                break;
        }
        return result;
    }

3. 显示逐小时天气情况

编写WeatherAdapter，用于显示逐小时天气情况

public class WeatherAdapter extends RecyclerView.Adapter<WeatherAdapter.WeatherViewHolder> {
    private Context context;  //上下文
    private List<Hours>  timeBean;   //天气信息

    public WeatherAdapter(Context context, List<Hours> timeBean) {
        this.context = context;
        this.timeBean = timeBean;
    }
    @NonNull
    @Override  //创建ViewHolder
    public WeatherViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(context).inflate(R.layout.recylerview_item,parent,false);
        WeatherViewHolder weatherViewHolder=new WeatherViewHolder(view);
        return weatherViewHolder;
    }
    @Override   //绑定ViewHolder，显示数据
    public void onBindViewHolder(@NonNull WeatherViewHolder holder, int position) {
        Hours hoursBean = timeBean.get(position); //根据位置获取该小时天气信息并显示
        holder.timeTv.setText(hoursBean.getHours());
        holder.timeWeatherTv.setText(hoursBean.getWea());
        holder.timeTempTv.setText(hoursBean.getTem());
        holder.timeWindTv.setText(hoursBean.getWin()+" "+hoursBean.getWin_speed());
    }

    @Override  //获取条目个数
    public int getItemCount() {
        return timeBean.size();
    }
    //ViewHolder
    class WeatherViewHolder extends RecyclerView.ViewHolder {
        TextView timeTv;
        TextView timeTempTv;
        TextView timeWeatherTv;
        TextView timeWindTv;
        public WeatherViewHolder(@NonNull View itemView) {   //对象与控件绑定
            super(itemView);
            timeTv = itemView.findViewById(R.id.timeTv);
            timeTempTv = itemView.findViewById(R.id.timeTempTv);
            timeWeatherTv = itemView.findViewById(R.id.timeWeatherTv);
            timeWindTv = itemView.findViewById(R.id.timeWindTv);
        }
    }
}

4. 点击事件监听器

设置点击事件，用于显示各种指数的详细信息和跳转浏览器查看更多天气

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.webTv:   //点击"查看更多天气"，跳转到浏览器界面
                Uri uri=Uri.parse("https://tianqi.qq.com/index.htm");
                Intent intent=new Intent();
                intent.setAction("android.intent.action.VIEW");
                intent.setData(uri);
                startActivity(intent);
                break;
            case R.id.clotheIv:   //点击穿衣指数弹出对话框
                showAlertDialog(clotheTitle,clotheLevel,clotheDesc);
                break;
            case R.id.UVIv:  //点击紫外线指数
                showAlertDialog(UVTitle,UVLevel,UVDesc);
                break;
            case R.id.sportIv:  //点击运动指数
                showAlertDialog(sportTitle,sportLevel,sportDesc);
                break;
            case R.id.carIv:  //点击洗车指数
                showAlertDialog(carTitle,carLevel,carDesc);
                break;
            case R.id.airPollutionIv:  //点击空气污染指数
                showAlertDialog(airTitle,airLevel,airDesc);
                break;
            case R.id.sickIv:  //点击血糖指数
                showAlertDialog(sickTitle,sickLevel,sickDesc);
                break;
        }
    }

编写showAlertDialog方法，用于显示对话框

    private void showAlertDialog(String title, String level, String desc) {
        AlertDialog.Builder builder= new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(title).setMessage("\n"+level+"\n\n"+desc).create().show();
    }

五、数据库创建和功能实现

编写CityDBHelper，继承SQLiteOpenHelper并重写方法

  private static SQLiteDatabase db;
    ContentValues values=new ContentValues();
    private long flag=0;

    public CityDBHelper(@Nullable Context context) {
        super(context, "city.db", null, 1);
        db=this.getWritableDatabase();
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        //创建表
        String sql = "create table city(id integer primary key autoincrement,city varchar(20) unique not null)";
        db.execSQL(sql);
    }
//添加数据
    public boolean addCity(String city){
        values.put("city",city);
        flag=db.insert("city",null,values);
        return flag>0?true:false;
    }
//根据城市名删除数据
    public boolean deleteCity(String city){
        flag=db.delete("city","city=?",new String[]{city});
        return flag>0?true:false;
    }
//查询全部数据
    public List<String> queryCity(){
        List<String> cityList=new ArrayList<>();
        Cursor cursor=db.query("city",null,null,null,null,null,null);
        if (cursor!=null){
            while (cursor.moveToNext()){
                String city=cursor.getString(1);
                cityList.add(city);
            }
        }
        return cityList;
    }
//根据城市名查询数据
    public boolean findCity(String city) {
        Cursor cursor = db.query("city", null, "city=?", new String[]{city}, null, null, null);
        if (cursor != null) {
            while (cursor.moveToNext()) {
                String findCity = cursor.getString(1);
                Log.i("Aye",findCity+"findCity");
                if (findCity != null) {
                    return false;
                } else {
                    return true;
                }
            }
        }
        return true;
    }
    @Override  //更新数据库
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }

六、城市管理界面功能实现

1. listView适配器配置

编写CityAdapter继承自BaseAdapter，为listView适配器

    private Context context;
    private List<String> cityList;

    public CityAdapter(Context context, List<String> cityList) {
        this.context = context;
        this.cityList = cityList;
    }
    @Override
    public int getCount() {  //集合条目个数
        return cityList.size();
    }

    @Override
    public Object getItem(int position) {   //根据位置获取条目信息
        return cityList.get(position);
    }

    @Override
    public long getItemId(int position) {  //获取位置
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder=null;
        if (convertView==null){  //如果convertView为空则初始化并绑定
            viewHolder=new ViewHolder();
            convertView=View.inflate(context, R.layout.city_listview_item,null);
            viewHolder.cityNameTv=convertView.findViewById(R.id.cityNameTv);
            convertView.setTag(viewHolder);
        }else {
            viewHolder=(ViewHolder)convertView.getTag();
        }
        //获取数据并显示
        viewHolder.cityNameTv.setText(cityList.get(position));
        return convertView;
    }
    class ViewHolder{
        TextView cityNameTv;
    }

4. 控件监听事件

为界面控件添加监听事件，用于跳转到添加城市界面和删除城市

        //添加城市，跳转到添加城市界面
        findTv.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(CityActivity.this,AddActivity.class));
            }
        });
        //长按删除城市
     showLv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                String deleteCity=cityList.get(position);   //根据长按点击位置获取内容
                //弹出对话框
                AlertDialog.Builder builder= new AlertDialog.Builder(CityActivity.this);
                builder.setTitle("提示").setMessage("是否删除该城市天气信息？")
                        .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                            }
                        })
                        .setPositiveButton("删除", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                 //调用数据库方法删除条目
                                flag=cityDBHelper.deleteCity(deleteCity); 
                                if (flag){
                                    Toast.makeText(CityActivity.this,"删除成功",Toast.LENGTH_SHORT).show();
                                    initView();
                                    //发送广播，通知更新天气数据
                                    Intent intent=new Intent("UPDATE1");
                                    sendBroadcast(intent);
                                }else {
                                    Toast.makeText(CityActivity.this,"删除失败",Toast.LENGTH_SHORT).show();
                                }
                            }
                        })
                        .create().show();
                return true;
            }
        });

七、添加城市界面功能实现

1. 适配器配置、通过省会添加城市功能实现

    private Context context;
    private List<String> cityList;
    private CityDBHelper cityDBHelper;

    public AddAdapter(Context context, List<String> cityList,CityDBHelper cityDBHelper) {
        this.context = context;
        this.cityList = cityList;
        this.cityDBHelper=cityDBHelper;
    }

    @NonNull
    @Override  //创建ViewHolder
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view=View.inflate(context,R.layout.add_recylerview_item,null);
        ViewHolder viewHolder = new ViewHolder(view);
        return viewHolder;
    }

    @Override  //绑定ViewHolder，显示数据，添加数据
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        holder.cityTv.setText(cityList.get(position));
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String clickCity=cityList.get(position);  //获取点击条目信息
                //判断点击条目是否为空，然后判断该城市是否已经添加到数据库中，最后判断是否添加成功
                if (clickCity!=null){
                    if (cityDBHelper.findCity(clickCity)) {
                        if (cityDBHelper.addCity(clickCity)) {
                            Toast.makeText(context,"添加成功",Toast.LENGTH_SHORT).show();
                            //发送广播，通知更新天气数据
                            Intent intent=new Intent("UPDATE");
                            context.sendBroadcast(intent);
                        }else {
                            Toast.makeText(context,"添加失败",Toast.LENGTH_SHORT).show();
                        }
                    }else {
                        Toast.makeText(context,"已存在该城市",Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }

    @Override
    public int getItemCount() {  //获取集合数目
        return cityList.size();
    }
//ViewHolder
    class ViewHolder extends RecyclerView.ViewHolder {
        TextView cityTv;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            cityTv=ite
                mView.findViewById(R.id.itemCityTv);
        }
    }

适配器绑定，数据传递

private String[] cityStrings=new String[]{"北京","天津","哈尔滨","沈阳","石家庄", "兰州", "西安", "郑州", "太原", "长沙", "南京", "贵阳",   "杭州", "广州", "台北",
                                          "上海" , "重庆", "长春", "呼和浩特", "乌鲁木齐", "西宁", "银川", "济南", "合肥", "武汉", "成都", "拉萨", "昆明", "南昌", "福州", "海口", "澳门"};
cityList=new ArrayList<>();
for (int i=0;i<cityStrings.length;i++){  //使用for集合将数组数据传入集合中
    cityList.add(cityStrings[i]);
}

addAdapter=new AddAdapter(this,cityList,cityDBHelper);
cityRv.setLayoutManager(new GridLayoutManager(this,3));  //适配器布局GridLayout，一行三个控件
cityRv.setAdapter(addAdapter);

4. 通过搜索添加城市功能实现

搜索键监听事件
findTv.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        String findCity=findEt.getText().toString();    //获取输入框中的内容
        //判断输入内容是否为空，再判断该城市是否已经存在数据库中，最后判断是否添加成功
        if (findCity!=null){
            if(cityDBHelper.findCity(findCity)){
                if (cityDBHelper.addCity(findCity)) {
                    Toast.makeText(AddActivity.this,"添加成功",Toast.LENGTH_SHORT).show();
                    //使用广播，通知天气信息更新
                    Intent intent=new Intent("UPDATE");
                    sendBroadcast(intent);
                }else {
                    Toast.makeText(AddActivity.this,"添加失败",Toast.LENGTH_SHORT).show();
                }
            }else {
                Toast.makeText(AddActivity.this,"已存在该城市",Toast.LENGTH_SHORT).show();
            }
        }else {
            Toast.makeText(AddActivity.this,"输入城市为空",Toast.LENGTH_SHORT).show();
        }
    }
});

5. 通过广播接收城市信息更新消息

在CityActivity文件中创建广播接收者

    @Override
    protected void onCreate(Bundle savedInstanceState) {      
myReceiver=new MyReceiver();
        //实例化过滤器并设置过滤的广播
        IntentFilter intentFilter=new IntentFilter();
        intentFilter.addAction("UPDATE");
        registerReceiver(myReceiver,intentFilter);  //注册广播
      
    }
    private class MyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            initView();  //收到广播信息后，更新界面
        }
    }

在MainActivity中也创建广播接收者

    @Override
    protected void onCreate(Bundle savedInstanceState) {
	    myReceiver=new MyReceiver();
        //实例化过滤器并设置过滤的广播
        IntentFilter intentFilter=new IntentFilter();
        intentFilter.addAction("UPDATE");
        intentFilter.addAction("UPDATE1");
        registerReceiver(myReceiver,intentFilter); //注册广播
        }
            private class MyReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            initPager();/收到广播信息后，更新界面
        }
    }