自己实现简单的天气预报应用（9）

 1 private void update(){
 2         Log.d(TAG,"在Update服务中启动");
 3         if(!configure.exists()){
 4             Toast.makeText(getApplicationContext(), R.string.fetching, Toast.LENGTH_SHORT).show();
 5             new  FetchAsyncTask().execute(url);
 6         }else{
 7             try{
 8                 hasNew = !(DateTools.getDate().equals(FileTools.loadConf(getApplicationContext())));
 9             }catch (IOException e){
10                 e.printStackTrace();
11             }
12             if(hasNew){
13                 Toast.makeText(getApplicationContext(),R.string.fetching,Toast.LENGTH_SHORT).show();
14                 new FetchAsyncTask().execute(url);
15             }
16         }
17     }
18 
19     private class FetchAsyncTask extends AsyncTask<String,Void,String> {
20 
21         @Override
22         protected String doInBackground(String... params) {
23             BufferedReader reader;
24             StringBuilder builder = new StringBuilder();
25             try{
26                 URL url=new URL(params[0]);
27                 HttpURLConnection connection=(HttpURLConnection)url.openConnection();
28                 InputStream in=connection.getInputStream();
29                 reader=new BufferedReader(new InputStreamReader(in));
30                 String line;
31                 while ((line = reader.readLine())!=null){
32                     builder.append(line);
33                 }
34             } catch(IOException e){
35                 e.printStackTrace();
36             }
37             return builder.toString();
38         }
39 
40         @Override
41         protected void onPostExecute(String s) {
42             Log.d(TAG, s);
43             try{
44                 ArrayList<WeatherItem> weatherItems = ParseTools.getInstance(s, ParseTools.REQUEST_RAW);
45 
46                 //保存数据到文件
47                 FileTools.saveData(getApplicationContext(), weatherItems);
48                 Toast.makeText(getApplicationContext(),"更新完毕",Toast.LENGTH_SHORT).show();
49 
50                 FileTools.saveWidgetData(getApplicationContext(), weatherItems.get(0));
51 
52                 Intent intent=new Intent(getApplicationContext(),UpdateService.class);
53                 startService(intent);
54             }catch (IOException | JSONException e){
55                 e.printStackTrace();
56             }
57             super.onPostExecute(s);
58         }
59     }

 1 private void update(){
 2         Log.d(TAG,"在主UI中启动");
 3         //只有第一次加载数据还没有下载完成的时候才会有mAdapter为空的情况
 4         if(mAdapter == null){
 5             mAdapter = new ItemAdapter(mWeatherItems);
 6             listView.setAdapter(mAdapter);
 7         }
 8 
 9         if(!configure.exists()){
10             Toast.makeText(getApplicationContext(),R.string.fetching,Toast.LENGTH_SHORT).show();
11             new FetchAsyncTask().execute(url);
12         }else{
13             try{
14                 hasNew = !(DateTools.getDate().equals(FileTools.loadConf(getApplicationContext())));
15             }catch (IOException e){
16                 e.printStackTrace();
17             }
18             if(hasNew){
19                 Toast.makeText(getApplicationContext(),R.string.fetching,Toast.LENGTH_SHORT).show();
20                 new FetchAsyncTask().execute(url);
21             }else{
22                 try{
23                     mWeatherItems=FileTools.loadData(getApplicationContext());
24                     mAdapter = new ItemAdapter(mWeatherItems);
25                     listView.setAdapter(mAdapter);
26                 }catch (IOException | JSONException e){
27                     e.printStackTrace();
28                 }
29             }
30         }
31     }
32 
33     private class FetchAsyncTask extends AsyncTask<String,Void,String>{
34 
35         @Override
36         protected String doInBackground(String... params) {
37             BufferedReader reader;
38             StringBuilder builder = new StringBuilder();
39             try{
40                 URL url=new URL(params[0]);
41                 HttpURLConnection connection=(HttpURLConnection)url.openConnection();
42                 InputStream in=connection.getInputStream();
43                 reader=new BufferedReader(new InputStreamReader(in));
44                 String line;
45                 while ((line = reader.readLine())!=null){
46                     builder.append(line);
47                 }
48             } catch(IOException e){
49                 e.printStackTrace();
50             }
51             return builder.toString();
52         }
53 
54         @Override
55         protected void onPostExecute(String s) {
56             Log.d(TAG,s);
57             try{
58                 mWeatherItems = ParseTools.getInstance(s,ParseTools.REQUEST_RAW);
59 
60                 //保存数据到文件
61                 FileTools.saveData(getApplicationContext(), mWeatherItems);
62                 Toast.makeText(getApplicationContext(),"更新完毕",Toast.LENGTH_SHORT).show();
63 
64                 mAdapter=new ItemAdapter(mWeatherItems);
65                 listView.setAdapter(mAdapter);
66 
67                 FileTools.saveWidgetData(getApplicationContext(), mWeatherItems.get(0));
68 
69                 Intent intent=new Intent(getApplicationContext(),UpdateService.class);
70                 startService(intent);
71             }catch (IOException | JSONException e){
72                 e.printStackTrace();
73             }
74             super.onPostExecute(s);
75         }
76     }