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来自Google官方的有关Android平台的JSON解析示例,如果远程服务器使用了json而不是xml的数据提供,在Android平台上已经内置的org.json包可以很方便的实现手机客户端的解析处理。下面安卓巴士一起分析下这个例子,帮助Android开发者需要有关 HTTP通讯、正则表达式、JSON解析、appWidget开发的一些知识 public class WordWidget extends AppWidgetProvider { //appWidget
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
context.startService(new Intent(context, UpdateService.class)); //避免ANR,所以Widget中开了个服务
}
public static class UpdateService extends Service {
@Override
public void onStart(Intent intent, int startId) {
// Build the widget update for today
RemoteViews updateViews = buildUpdate(this);
ComponentName thisWidget = new ComponentName(this, WordWidget.class);
AppWidgetManager manager = AppWidgetManager.getInstance(this);
manager.updateAppWidget(thisWidget, updateViews);
}
public RemoteViews buildUpdate(Context context) {
// Pick out month names from resources
Resources res = context.getResources();
String[] monthNames = res.getStringArray(R.array.month_names);
Time today = new Time();
today.setToNow();
String pageName = res.getString(R.string.template_wotd_title,
monthNames[today.month], today.monthDay);
RemoteViews updateViews = null;
String pageContent = "";
try {
SimpleWikiHelper.prepareUserAgent(context);
pageContent = SimpleWikiHelper.getPageContent(pageName, false);
} catch (ApiException e) {
Log.e("WordWidget", "Couldn't contact API", e);
} catch (ParseException e) {
Log.e("WordWidget", "Couldn't parse API response", e);
}
Pattern pattern = Pattern.compile(SimpleWikiHelper.WORD_OF_DAY_REGEX); //正则表达式处理,有关定义见下面的SimpleWikiHelper类
Matcher matcher = pattern.matcher(pageContent);
if (matcher.find()) {
updateViews = new RemoteViews(context.getPackageName(), R.layout.widget_word);
String wordTitle = matcher.group(1);
updateViews.setTextViewText(R.id.word_title, wordTitle);
updateViews.setTextViewText(R.id.word_type, matcher.group(2));
updateViews.setTextViewText(R.id.definition, matcher.group(3).trim());
String definePage = res.getString(R.string.template_define_url,
Uri.encode(wordTitle));
Intent defineIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(definePage)); //这里是打开相应的网页,所以Uri是http的url,action是view即打开web浏览器
PendingIntent pendingIntent = PendingIntent.getActivity(context,
0 /* no requestCode */, defineIntent, 0 /* no flags */);
updateViews.setOnClickPendingIntent(R.id.widget, pendingIntent); //单击Widget打开Activity
} else {
updateViews = new RemoteViews(context.getPackageName(), R.layout.widget_message);
CharSequence errorMessage = context.getText(R.string.widget_error);
updateViews.setTextViewText(R.id.message, errorMessage);
}
return updateViews;
}
@Override
public IBinder onBind(Intent intent) {
// We don't need to bind to this service
return null;
}
}
}
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