Excessive JNI global references - Android

ContentObserver is used in ContentService

ObserverNode is a capsulation of ObserverEntry to provide addObserverLocked method and so on.

./frameworks/base/core/java/android/content/ContentService.java calls registerContentObserver method to register uri and responding observer.

during this registering, a ObserverNode instance would be created, so, a ObserverEntry would be created as a observer list.

./frameworks/base/services/java/com/android/server/SystemServer.java initializes ContentService via ContentService.main.

 

 

 

 

 

 

 

Here is a example for using ContentObserver.
http://www.eoeandroid.com/forum.php?mod=viewthread&tid=9162&page=1

最近有个朋友问了我如何接受指定号码的短信，并且不让系统截取到通知用户。真好前端时间看天朝group，也有个朋友问了这个问题，而且通过ContentObserver方式解决了，我这里就把我实现的代码贴出来，以便需要的朋友参考。

   1. public class ScreenTest extends Activity {
   2.       
   3.         class SmsContent extends ContentObserver{
   4.                 private Cursor cursor = null;
   5.                 public SmsContent(Handler handler) {
   6.                         super(handler);
   7.                 }
   8.               
   9.                 /**
  10.                  * @Description 当短信表发送改变时，调用该方法
  11.                  *                                 需要两种权限
  12.                  *                                 android.permission.READ_SMS读取短信
  13.                  *                                 android.permission.WRITE_SMS写短信
  14.                  * @Author Snake
  15.                  * @Date 2010-1-12
  16.                  */
  17.                 @Override
  18.                 public void onChange(boolean selfChange) {
  19.                         // TODO Auto-generated method stub
  20.                         super.onChange(selfChange);
  21.                         //读取收件箱中指定号码的短信
  22.                         cursor = managedQuery(Uri.parse("content://sms/inbox"),
                                                    new String[]{"_id", "address", "read"},
                                                    " address=? and read=?",
                                                    new String[]{"12345678901", "0"},
                                                    "date desc");
  23.                       
  24.                         if (cursor != null){
  25.                                 ContentValues values = new ContentValues();
  26.                                 values.put("read", "1");                //修改短信为已读模式
  27.                                 cursor.moveToFirst();
  28.                                 while (cursor.isLast()){
  29.                                         //更新当前未读短信状态为已读
  30.                                         getContentResolver().update(Uri.parse("content://sms/inbox"),
                                                                          values,
                                                                          " _id=?",
                                                                          new String[]{""+cursor.getInt(0)});
  31.                                         cursor.moveToNext();
  32.                                 }
  33.                         }
  34.                 }
  35.         }
  36.       
  37.     /** Called when the activity is first created. */
  38.     @Override
  39.     public void onCreate(Bundle savedInstanceState) {
  40.         super.onCreate(savedInstanceState);
  41.         setContentView(R.layout.main);
  42.         SmsContent content = new SmsContent(new Handler());
  43.         //注册短信变化监听
  44.         this.getContentResolver().registerContentObserver(Uri.parse("content://sms/"), true, content);
  45.     }
  46. }