三、天氣預報App基本功能實現
天氣預報主要功能就是根據城市的代碼，去動態獲取當前的天氣情況，並且將當前的選擇的城市天氣信息保存下來（Sharedpreferences）.
1、獲取JSon天氣數據
2、根據android基礎學習綜合實例——天氣預報App中分析的城市代碼以及天氣代碼，保存到數據庫中，再根據用戶所選擇的城市代碼，獲取對應的天氣信息
3、特別註意，因為白天已經過去 ,預報在晚上那次更新的時候白天數據就會為空，即中國氣象局的數據在晚上6點以後不會再更新白天的數據信息，在App中必須保存白天的天氣信息。
3.1 城市代碼數據庫建立
(1)省份Province代碼數據庫：包括省份名稱和代碼
private static final String CREATE_PROVINCE = "create table Province ("
+ "id integer primary key autoincrement, "
+ "province_name text, "
+ "province_code text)";添加對應的數據庫操作
1)保存省份實例到數據庫中
public void saveProvince(Province province)
{
if (province != null)
{
ContentValues values = new ContentValues();
values.put("province_name", province.getProvinceName());
values.put("province_code", province.getProvinceCode());
db.insert("Province", null, values);
}
}2.在數據庫中讀取全國的所有省份
public List<Province> loadProvices()
{
List<Province> list = new ArrayList<Province>();
Cursor cursor = db
.query("Province", null, null, null, null, null, null);
if (cursor.moveToFirst())
{
do
{
Province province = new Province(); province.setId(cursor.getInt(cursor.getColumnIndex("id")));
province.setProvinceName(cursor.getString(cursor
.getColumnIndex("province_name")));
province.setProvinceCode(cursor.getString(cursor
.getColumnIndex("province_code")));
list.add(province);
} while (cursor.moveToNext());
}
return list;
}（2）市級City代碼數據庫表建立
private static final String CREATE_CITY = "create table City ("
+ "id integer primary key autoincrement, "
+ "city_name text, "
+ "city_code text, "
+ "province_id integer)";1.保存City信息到數據庫中
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);
}
}2.根據用戶所選的省份id，在數據庫中讀取對應的市級城市數據
public List<City> loadCity(int provinceId)
{
List<City> 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;
}（3）縣級County城市代碼數據庫建立
private static final String CREATE_COUNTY = "create table County ("
+ "id integer primary key autoincrement, "
+ "county_name text, "
+ "county_code text, "
+ "city_id integer)";1.保存County信息到數據庫中
public void saveCounty(County county)
{
if (county != null)
{
ContentValues values = new ContentValues();
values.put("county_name", county.getCountyName());
values.put("county_code", county.getCountyCode());
values.put("city_id", county.getCityId());
db.insert("County", null, values);
}
}2.根據City的id在數據中獲取對應的縣城數據
public List<County> loadCounties(int cityId)
{
List<County> list = new ArrayList<County>();
Cursor cursor = db.query("County", null, "city_id = ?", new String[]
{ String.valueOf(cityId) }, null, null, null);
if (cursor.moveToFirst())
{
do
{
County county = new County();
county.setCityId(cursor.getInt(cursor.getColumnIndex("id")));
county.setCountyName(cursor.getString(cursor
.getColumnIndex("county_name")));
county.setCountyCode(cursor.getString(cursor
.getColumnIndex("county_code")));
county.setCityId(cityId);
list.add(county);
} while (cursor.moveToNext());
}
return list;
}3.2 根據城市代碼在線獲取城市的天氣信息
因為中國氣象局返回的數據是JSon格式的，所以我們通過解析JSon格式的數據，獲得對應的天氣信息。
（1）根據城市代碼在線獲取天氣JSon數據
public static void sendHttpRequest(final String address,
final HttpCallbackListener listener)
{
new Thread(new Runnable()
{
@Override
public void run()
{
HttpURLConnection connection = null;
URL url;
try
{
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,"UTF-8"));//這裏用UTF-8是為了防止獲取得到的JSON數據中出現中文而導致亂碼
StringBuilder response = new StringBuilder();
String line;
while ((line = reader.readLine()) != null)
{
response.append(line);
}
if (listener != null)
{
// 回調onFinish()方法
listener.onFinish(response.toString());
}
in.close();
} catch (Exception e)
{
if (listener != null) {
// 回調onError()方法
listener.onError(e);
}
} finally{
if(connection != null){
connection.disconnect();
}
}
}
}).start();
}其中listener是自定義的一個回調接口，通過回調接口可方便獲得返回的天氣信息response
public interface HttpCallbackListener
{
void onFinish(String response);
void onError(Exception e);
}以上都是基本準備工作，本APP中主要包括2個Activity：ChooseAreaAcitvity和WeatherActivity。
3.3 ChooseAreaActivity：通過讀取Excel獲取城市的代碼以及名稱並顯示
public static String loadProvincesInfo(Context context,String xlsPath) throws IOException
{
if(xlsPath.equals("Area_Excel")){
StringBuilder provinceInfo= new StringBuilder();
try{
InputStream is = context.getAssets().open("areaid_v.xls");
//ileInputStream fileIn = new FileInputStream(xlsPath);
// 根據指定的文件輸入流導入Excel從而產生Workbook對象
HSSFWorkbook wb0 = new HSSFWorkbook(is);
// 獲取Excel文檔中的第一個表單
HSSFSheet hssfSheet = wb0.getSheetAt(0);
// 對Sheet中的每一行進行叠代
for (int rowNum = 1; rowNum <= hssfSheet.getLastRowNum(); rowNum++)
{
HSSFRow hssfRow = hssfSheet.getRow(rowNum);
// 如果當前行的行號（從0開始）未達到2（第三行）則從新循環
if (hssfRow != null)
{
// 創建實體類
HSSFCell no = hssfRow.getCell(0);
HSSFCell proname = hssfRow.getCell(6);
HSSFCell cityname = hssfRow.getCell(4);
HSSFCell countyname = hssfRow.getCell(2);
/*
* String subNo = getValue(no).substring(3, 5);//[3,5)
*/
//返回一行中的省市縣的名稱已經整個Number
String info = getValue(no) + "|" + getValue(proname) + "|"
+ getValue(cityname) + "|" + getValue(countyname) + ",";
provinceInfo.append(info);
}
}
/*fileIn.close();*/
is.close();
return provinceInfo.toString();
}catch(Exception e){
Log.d("TAG", "加載excel文件出錯");
}
return provinceInfo.toString();
}else{
Log.d("TAG", "加載excel類型出錯，應該為地區類型");
return null;
}
}Tags:
文章來源：