/**
* A particular {@link AsyncQueryHandler} allowing clients to be notified via a
* listener. The {@link NotifyingAsyncQueryHandler} also make sure no strong
* reference is kept on the given listener (as it is often a Context).
*
*/
public class DBAsyncHandler extends AsyncQueryHandler {
private WeakReference<DBAsyncListener> mListener;
/**
* Client may use this to listen to completed query operations. run on UI
* Thread
*/
public static class DBAsyncListener {
public DBAsyncListener() {
}
/**
* run on UI Thread <br />
* <b>cursor close() method needn't be called</b>
*/
protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
}
protected void onInsertComplete(int token, Object cookie, Uri uri) {
}
protected void onUpdateComplete(int token, Object cookie, int result) {
}
protected void onDeleteComplete(int token, Object cookie, int result) {
}
}
/**instance in UI Thread*/
public DBAsyncHandler(ContentResolver resolver, DBAsyncListener listener) {
super(resolver);
setDBListener(listener);
}
/**
* Assign the given {@link DBAsyncListener}.
*/
public void setDBListener(DBAsyncListener listener) {
mListener = (listener != null) ? new WeakReference<DBAsyncListener>(listener) : null;
}
private DBAsyncListener getDBListener() {
return (mListener == null) ? null : mListener.get();
}
/** such as Activity-onDestory(), this method is called */
public void clearDBListener() {
mListener = null;
}
public void startQuery(int token, Object cookie, Uri uri, String[] projection, String selection, String[] selectionArgs, String orderBy) {
super.startQuery(token, cookie, uri, projection, selection, selectionArgs, orderBy);
}
@Override
protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
DBAsyncListener listener = getDBListener();
if (listener != null) {
listener.onQueryComplete(token, cookie, cursor);
if (cursor != null && !cursor.isClosed())
cursor.close();
} else if (cursor != null) {
cursor.close();
}
}
@Override
protected void onDeleteComplete(int token, Object cookie, int result) {
DBAsyncListener listener = getDBListener();
if (listener != null) {
listener.onDeleteComplete(token, cookie, result);
}
}
@Override
protected void onInsertComplete(int token, Object cookie, Uri uri) {
DBAsyncListener listener = getDBListener();
if (listener != null) {
listener.onInsertComplete(token, cookie, uri);
}
}
@Override
protected void onUpdateComplete(int token, Object cookie, int result) {
DBAsyncListener listener = getDBListener();
if (listener != null) {
listener.onUpdateComplete(token, cookie, result);
}
}
}public class MyProvider extends ContentProvider {
private final static String TAG = MyProvider.class.getSimpleName();
private final static int Person = 1;
public final static String BASE = "com.baidu.my.provider";
public final static Uri URI_Person = Uri.parse("content://com.baidu.my.provider/Person");
private final static UriMatcher MATCHER = new UriMatcher(UriMatcher.NO_MATCH); // 如果都匹配不成功，则返回构造函数中指定的参数值，默认为-1
private SQLiteDatabase db;
static {
MATCHER.addURI(BASE, "Person", Person);
}
@Override
public boolean onCreate() {
MyDBHelper dbHelper = new MyDBHelper(this.getContext());
db = dbHelper.getWritableDatabase();
return true;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
Cursor c = null;
switch (MATCHER.match(uri)) {
case Person:
c = db.query(DBPerson.TableName, projection, selection, selectionArgs, null, null, sortOrder);
c.setNotificationUri(getContext().getContentResolver(), URI_Person);
break;
default:
break;
}
return c;
}
@Override
public String getType(Uri uri) {
switch (MATCHER.match(uri)) {
case Person:
return "vnd.android.cursor.dir/vnd." + BASE + ".request";
default:
break;
}
return null;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
long id = 0;
switch (MATCHER.match(uri)) {
case Person:
id = db.insert(DBPerson.TableName, null, values);
if (id > 0) {
// 数据发生改变，发出通知
getContext().getContentResolver().notifyChange(URI_Person, null);
}
return ContentUris.withAppendedId(uri, id);
}
return null;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
// TODO Auto-generated method stub
return 0;
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
// TODO Auto-generated method stub
return 0;
}
}public class MyDBHelper extends SQLiteOpenHelper {
private static final String TAG = "DBHelper";
private static final String DB_NAME = "my.db";
private static final int DB_VERSION = /**/ 57 /**/;/****谨慎修改，否则将导致用户历史数据被删除****/
public MyDBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(getRequestCreateStr());
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + DBPerson.TableName);
onCreate(db);
}
private String getRequestCreateStr() {
StringBuffer sb = new StringBuffer();
sb.append("CREATE TABLE ").append(DBPerson.TableName);
sb.append(" (");
sb.append(BaseColumns._ID).append(" INTEGER PRIMARY KEY,");
sb.append(DBPerson.MetaDate.Name).append(" TEXT,");
sb.append(DBPerson.MetaDate.Age).append(" TEXT)");
return sb.toString();
}
}public interface DBPerson extends BaseDB{
public interface MetaDate {
String Name = "Name";
String Age = "Age";
}
public String TableName = "Person";
public String[] PROJECTION = {
MetaDate.Name, MetaDate.Age
};
public String SORT_ORDER = MetaDate.Age + " ASC";
}public class MainActivity extends Activity {
private DBAsyncHandler dbAsyncHandler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//
dbAsyncHandler = new DBAsyncHandler(getContentResolver(), dbListener);
}
private DBAsyncHandler.DBAsyncListener dbListener = new DBAsyncListener() {
protected void onQueryComplete(int token, Object cookie, Cursor cursor) {
Toast.makeText(getApplicationContext(), "ok = " + cursor.getCount(), 1).show();
}
protected void onInsertComplete(int token, Object cookie, android.net.Uri uri) {
Toast.makeText(getApplicationContext(), "插入ok！", 1).show();
}
};
public void query(View view) {
//query
dbAsyncHandler.startQuery(100, null, MyProvider.URI_Person, DBPerson.PROJECTION, null, null, DBPerson.SORT_ORDER);
}
public void insert(View view) {
//insert
ContentValues initialValues = new ContentValues();
initialValues.put(DBPerson.MetaDate.Name, "baidu");
initialValues.put(DBPerson.MetaDate.Age, System.currentTimeMillis());
dbAsyncHandler.startInsert(100, null, MyProvider.URI_Person, initialValues);
}
@Override
protected void onDestroy() {
//clear
dbAsyncHandler.clearDBListener();
super.onDestroy();
}
}
原文地址：http://blog.csdn.net/zimo2013/article/details/39993373
