Android - 实训项目总结

Android
1.简介
1.1项目简介
    Coolweather是一款基于Android的天气查询软件,实现了省市县的遍历、县级地区天气的查询、手动更新天气、8小时的自动更新天气信息;
1.2项目责任
    xx:测试代码的编写实现
    xx:软件调式修改
    xx:项目框架和文档编写
1.3项目内容
    项目结构:
-com.example.app
--activity
---ChooseAreaActivity
---WeatherActivity
--db
---CoolWeatherOpenHelper
---CoolWeatherDB
--model
---Province
---City
---County
--receiver
---AutoUpdateReceiver
--service
---AutoUpdateService
--util
---HttpUtil
---HttpCallbackListener

PS:
activity 包用于存放所有活动相关的代码，
---ChooseAreaActivity 遍历省市县数据
---WeatherActivity 显示天气活动
db 包用于存放所有数据库相关的代码，
---CoolWeatherOpenHelper 数据库辅助类,创建一个数据库+三张表
---CoolWeatherDB 数据库数据操作封装类
model 包用于存放所有模型相关的代码，
---Province 省实体类
---City 市实体类
---County 县实体类
receiver 包用于存放所有广播接收器相关的代码，
---AutoUpdateReceiver 自动更新天气
service 包用于存放所有服务相关的代码，
---AutoUpdateService 手动更新天气
util 包用于存放所有工具相关的代码
---HttpUtil
---HttpCallbackListener 与服务器的交互类
2.核心代码

// db->CoolWeatherDB->saveCity(...)
// 将City实例存储到数据库
public void saveCity(City city) {
    if (city != null) {
        ContentValues values = new ContentValues();
        values.put("city_name", city.getCityName());
        values.put("city_code", city.getCityCode());
        values.put("province_id", city.getProvinceId());
        db.insert("City", null, values);
    }

}

// db->CoolWeatherDB->loadCities(...)
// 读取某省内所有城市数据
public List loadCities(int provinceId) {
    List list = new ArrayList();
    Cursor cursor = db.query("City", null, "province_id = ?",new String[] { String.valueOf(provinceId) }, null, null, null);
    if (cursor.moveToFirst()) {
        do {
            City city = new City();
            city.setId(cursor.getInt(cursor.getColumnIndex("id")));
            city.setCityName(cursor.getString(cursor.getColumnIndex("city_name")));
            city.setCityCode(cursor.getString(cursor.getColumnIndex("city_code")));
            city.setProvinceId(provinceId);
            list.add(city);
        } while (cursor.moveToNext());
    }
    return list;
}

// util->HttpUtil->sendHttpRequest(...)
// 发送HTTP请求到服务器,获取返回的结果
public static void sendHttpRequest(final String address,final HttpCallbackListener listener) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                try {
                    URL url = new URL(address);
                    connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    InputStream in = connection.getInputStream();
                    BufferedReader reader = new BufferedReader(new
                    InputStreamReader(in));
                    StringBuilder response = new StringBuilder();
                    String line;
                    while ((line = reader.readLine()) != null) {
                        response.append(line);
                    }
                    if (listener != null) {
                        // 回调onFinish()方法
                        listener.onFinish(response.toString());
                    }
                } catch (Exception e) {
                    if (listener != null) {
                    // 回调onError()方法
                    listener.onError(e);
                }
                } finally {
                    if (connection != null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }


// util->HttpUtil->handleCitiesResponse(...)
// 解析http请求返回的数据(省市县)
public static boolean handleCitiesResponse(CoolWeatherDB coolWeatherDB,String response, int provinceId) {
        if (!TextUtils.isEmpty(response)) {
            //按逗号分隔
            String[] allCities = response.split(",");
            if (allCities != null && allCities.length > 0) {
                for (String c : allCities) {
                    //按单竖线分隔
                    String[] array = c.split("\\|");
                    City city = new City();
                    city.setCityCode(array[0]);
                    city.setCityName(array[1]);
                    city.setProvinceId(provinceId);
                    // 将解析出来的数据存储到City表
                    coolWeatherDB.saveCity(city);
                }
                return true;
            }
        }
        return false;
    }

// util->HttpUtil->handleWeatherResponse(...)
// 解析http请求返回的天气数据
public static void handleWeatherResponse(Context context, String response) {
        try {
            String temp = new String(response.getBytes(), "utf-8");// 将数据以utf-8的编码方式获取出来
            JSONObject dataOfJson = new JSONObject(temp);
            JSONArray heWeatherArray = dataOfJson.getJSONArray("HeWeather data service 3.0");
            JSONObject heWeatherArray0 = heWeatherArray.getJSONObject(0);
            JSONObject basic = heWeatherArray0.getJSONObject("basic");

            String cityName = basic.getString("city");
            String weatherCode0 = basic.getString("id");
            String weatherCode = weatherCode0.substring(2, 11);

            JSONObject updateJson = basic.getJSONObject("update");
            String publishTime0 = updateJson.getString("loc");
            String publishTime = publishTime0.substring(11, 16);

            JSONArray daily_forecast = heWeatherArray0.getJSONArray("daily_forecast");
            JSONObject daily_forecast0 = daily_forecast.getJSONObject(0);
            JSONObject cond = daily_forecast0.getJSONObject("cond");
            String txt_d = cond.getString("txt_d");
            String txt_n = cond.getString("txt_n");

            String weatherDiscribe;
            if (txt_d.equals(txt_n)) {
                weatherDiscribe = txt_d;
            } else {
                weatherDiscribe = txt_d + "转" + txt_n;
            }

            JSONObject tmp = daily_forecast0.getJSONObject("tmp");
            String temp10 = tmp.getString("min");
            String temp1 = temp10 + "℃";
            String temp20 = tmp.getString("max");
            String temp2 = temp20 + "℃";
            Log.d("Utility", cityName + weatherCode + temp1 + temp2+ weatherDiscribe + publishTime);
            saveWeatherInfo(context, cityName, weatherCode, temp1, temp2,weatherDiscribe, publishTime);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }


// activity->ChooseAreaActivity->queryCities()
// 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 queryCities() {
        cityList = coolWeatherDB.loadCities(selectedProvince.getId());
        if (cityList.size() > 0) {
            dataList.clear();
            for (City city : cityList) {
                dataList.add(city.getCityName());
            }
            adapter.notifyDataSetChanged();
            listView.setSelection(0);
            titleText.setText(selectedProvince.getProvinceName());
            currentLevel = LEVEL_CITY;
        } else {
            queryFromServer(selectedProvince.getProvinceCode(), "city");
        }
    }


// activity->ChooseAreaActivity->queryFromServer(...)
// 去服务器上查询
private void queryFromServer(final String code, final String type) {
        String address;
        if (!TextUtils.isEmpty(code)) {
            address = "http://www.weather.com.cn/data/list3/city" + code +".xml";
        } else {
            address = "http://www.weather.com.cn/data/list3/city.xml";
        }

        showProgressDialog();

        HttpUtil.sendHttpRequest(address, new HttpCallbackListener() {
            @Override
            public void onFinish(String response) {
                boolean result = false;
                if ("province".equals(type)) {
                    result = Utility.handleProvincesResponse(coolWeatherDB,response);
                } else if ("city".equals(type)) {
                    result = Utility.handleCitiesResponse(coolWeatherDB,response, selectedProvince.getId());
                } else if ("county".equals(type)) {
                    result = Utility.handleCountiesResponse(coolWeatherDB,response, selectedCity.getId());
                }
                if (result) {
                    // 通过runOnUiThread()方法回到主线程处理逻辑
                    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 onError(Exception e) {
                // 通过runOnUiThread()方法回到主线程处理逻辑
                runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    closeProgressDialog();
                    Toast.makeText(ChooseAreaActivity.this,"加载失败", Toast.LENGTH_SHORT).show();
                }
                });
            }
        });
    }



// activity->WeatherActivity>queryWeatherInfo(...)
// 根据天气代号查询天气信息
private void queryWeatherInfo(String weatherCode) {
    String address = "http://api.heweather.com/x3/weather?cityid=CN"+ weatherCode + "&key=3e9f4017110547f2b74237fdc7152f38";
    queryFromServer(address, "weatherCode");
}


// Service->AutoUpdateService>onStartCommand(...)
// 更新天气
public int onStartCommand(Intent intent, int flags, int startId) {
    new Thread(new Runnable() {
        @Override
        public void run() {
            updateWeather();
        }
    }).start();
    AlarmManager manager = (AlarmManager) getSystemService(ALARM_SERVICE);
    int anHour = 8 * 60 * 60 * 1000; // 这是8小时的毫秒数
    long triggerAtTime = SystemClock.elapsedRealtime() + anHour;
    Intent i = new Intent(this, AutoUpdateReceiver.class);
    PendingIntent pi = PendingIntent.getBroadcast(this, 0, i, 0);
    manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtTime, pi);
    return super.onStartCommand(intent, flags, startId);
}
// Service->AutoUpdateService>updateWeather(...)
// 更新天气
SharedPreferences prefs = PreferenceManager.
getDefaultSharedPreferences(this);
String weatherCode = prefs.getString("weather_code", "");
String address = "http://api.heweather.com/x3/weather?cityid=CN"+ weatherCode + "&key=3e9f4017110547f2b74237fdc7152f38";
HttpUtil.sendHttpRequest(address, new HttpCallbackListener() {........}


// Receiver>AutoUpdateReceiver
// 自动更新天气
public class AutoUpdateReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        Intent i = new Intent(context, AutoUpdateService.class);
        context.startService(i);
    }
}


//定时处理
AlarmManager manager = (AlarmManager) getSystemService(ALARM_SERVICE);
int anHour = 8 * 60 * 60 * 1000; // 这是8小时的毫秒数
long triggerAtTime = SystemClock.elapsedRealtime() + anHour;
Intent i = new Intent(this, AutoUpdateReceiver.class);
PendingIntent pi = PendingIntent.getBroadcast(this, 0, i, 0);
manager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtTime, pi);
return super.onStartCommand(intent, flags, startId);

3.项目总结
    实习期间，做了一个Android小项目;虽然已经学了很久，但是真到自己动手的时候会发现遇到了各种问题;
    首先,讲述一下从中获得了什么?
    (1)CoolWeather这款软件主要利用了HttpURLConnection完成HTTP请求,进行对返回数据的XML解析、JSON解析;
    (2)运用了数据库SQLiteDateBase进行省市县数据的存储以及操作,
    (3)运用SharedPreferences,进行实时天气信息的存储
    (4)Service 服务的后台运行
    (5)Receiver 广播接收器的定时处理
    其次,简单讲述一下遇到的问题
    (1)广播接收器运用时，onReceive()总是崩溃 - 忘记注册(已解决)
    (2)UI界面更新会出现ANR错误 - 延时处理的操作没有在子线程完成(已解决)
    (3)ListView数据没有实时显示 - 适配器未提醒更新(已解决)
    最后,感谢这样的一次实习机会，Android开发水平有了进一步的提升;