ContentProvider,ContentResolver,ContentObserver
ContentProvider:
public class ConstantData {
public static final String DATABASE_NAME = "person.db";
public static final int DATABASE_VERSION = 4;
public static final String TABLE_NAME = "person";
public static final String AUTHORITY = "com.mcxtzhang.flowlayoutmanager.zuimei.mycontentprovider";
public static final class PersonData implements BaseColumns {
public static final String TABLE_NAME = "person";
public static final Uri CONTENT_URI = Uri.parse("content://"+AUTHORITY+"/person");
public static final String DIR_CONTENT_TYPE = "vnd.android.cursor.dir/";
public static final String ITEM_CONTENT_TYPE = "vnd.android.cursor.item/";
public static final int PERSON_CODE = 1;
public static final int PERSION_ID_CODE = 2;
public static final String NAME = "name";
public static final String SONG = "song";
public static final String DEFAULT_SORT_ORDER = "_id desc";
public static final UriMatcher uriMatcher;
static {
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(AUTHORITY,"person",PERSON_CODE);
uriMatcher.addURI(AUTHORITY,"person/#",PERSION_ID_CODE);
}
}
}
public class DBOpenHelper extends SQLiteOpenHelper {
public DBOpenHelper(Context context){
super(context,ConstantData.DATABASE_NAME,null,ConstantData.DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + ConstantData.TABLE_NAME
+"("
+ConstantData.PersonData._ID + " INTEGER PRIMARY KEY autoincrement,"
+ConstantData.PersonData.NAME + " varchar(20),"
+ConstantData.PersonData.SONG + " varchar(100)"
+ ");");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
public class MyContentProvider extends ContentProvider {
private DBOpenHelper dbOpenHelper = null;
@Nullable
@Override
public String getType(@NonNull Uri uri) {
switch (ConstantData.PersonData.uriMatcher.match(uri)){
case ConstantData.PersonData.PERSON_CODE:
return ConstantData.PersonData.DIR_CONTENT_TYPE;
case ConstantData.PersonData.PERSION_ID_CODE:
return ConstantData.PersonData.ITEM_CONTENT_TYPE;
default:
throw new IllegalArgumentException("Unknown uri " + uri);
}
}
@Override
public int update(@NonNull Uri uri, @Nullable ContentValues values, @Nullable String selection, @Nullable String[] selectionArgs) {
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
int count = 0;
switch (ConstantData.PersonData.uriMatcher.match(uri)){
case ConstantData.PersonData.PERSON_CODE:
count = db.update(ConstantData.TABLE_NAME,values,selection,selectionArgs);
break;
case ConstantData.PersonData.PERSION_ID_CODE:
long personid = ContentUris.parseId(uri);
String where = "_ID=" + personid;
where += !TextUtils.isEmpty(selection)? " and (" + selection + ")" : "";
count = db.update(ConstantData.TABLE_NAME,values,where,selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown uri "+ uri);
}
db.close();
getContext().getContentResolver().notifyChange(uri,null);
return count;
}
@Nullable
@Override
public Uri insert(@NonNull Uri uri, @Nullable ContentValues values) {
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
long id = 0;
Uri insertUri = null;
switch (ConstantData.PersonData.uriMatcher.match(uri)){
case ConstantData.PersonData.PERSON_CODE:
id = db.insert(ConstantData.TABLE_NAME,null,values);
insertUri = ContentUris.withAppendedId(uri,id);
break;
case ConstantData.PersonData.PERSION_ID_CODE:
id = db.insert(ConstantData.TABLE_NAME,null,values);
String path = uri.toString();
insertUri = Uri.parse(path.substring(0,path.lastIndexOf("/")) + id);
break;
default:
throw new IllegalArgumentException("Unknown uri "+ uri);
}
db.close();
getContext().getContentResolver().notifyChange(uri,null);
return insertUri;
}
@Override
public boolean onCreate() {
dbOpenHelper = new DBOpenHelper(getContext());
return true;
}
@Override
public int delete(@NonNull Uri uri, @Nullable String selection, @Nullable String[] selectionArgs) {
SQLiteDatabase db = dbOpenHelper.getWritableDatabase();
int count = 0;
switch (ConstantData.PersonData.uriMatcher.match(uri)){
case ConstantData.PersonData.PERSON_CODE:
count = db.delete(ConstantData.TABLE_NAME,selection,selectionArgs);
break;
case ConstantData.PersonData.PERSION_ID_CODE:
long personid = ContentUris.parseId(uri);
String where = "_ID="+personid;
where += !TextUtils.isEmpty(selection)? " and (" + selection + ")" : "";
count = db.delete(ConstantData.TABLE_NAME,where,selectionArgs);
break;
default:
throw new IllegalArgumentException("Unknown uri " + uri);
}
db.close();
getContext().getContentResolver().notifyChange(uri,null);
return count;
}
@Nullable
@Override
public Cursor query(@NonNull Uri uri, @Nullable String[] projection, @Nullable String selection, @Nullable String[] selectionArgs, @Nullable String sortOrder) {
SQLiteDatabase db = dbOpenHelper.getReadableDatabase();
Cursor cursor = null;
switch (ConstantData.PersonData.uriMatcher.match(uri)){
case ConstantData.PersonData.PERSON_CODE:
cursor = db.query(ConstantData.TABLE_NAME,projection,selection,selectionArgs,null,null,sortOrder);
break;
case ConstantData.PersonData.PERSION_ID_CODE:
long personid = ContentUris.parseId(uri);
String where = "_ID=" + personid;
where += !TextUtils.isEmpty(selection)? " and (" + selection + ")" : "";
cursor = db.query(ConstantData.TABLE_NAME,projection,where,selectionArgs,null,null,sortOrder);
break;
default:
throw new IllegalArgumentException("Unknown uri "+ uri);
}
// db.close();
return cursor;
}
}
ContentObserver和ContentResolver
public class Main3Activity extends AppCompatActivity {
private Button insertBtn,deleteBtn,updateBtn,queryBtn;
private Uri uri = Uri.parse("content://com.mcxtzhang.flowlayoutmanager.zuimei.mycontentprovider/person");
private int count = 0;
private ListView songList;
private PersonObserver personObserver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main3);
insertBtn = (Button)findViewById(R.id.insertBtn);
deleteBtn = (Button)findViewById(R.id.deleteBtn);
updateBtn = (Button)findViewById(R.id.updateBtn);
queryBtn = (Button)findViewById(R.id.queryBtn);
songList = (ListView)findViewById(R.id.songList);
final ContentResolver contentResolver = getContentResolver();
personObserver = new PersonObserver(new Handler());
insertBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ContentValues contentValues = new ContentValues();
contentValues.put("name","講真的"+ count);
contentValues.put("song","今夜特别漫長，有個号碼一直被存放");
contentResolver.insert(uri,contentValues);
count ++;
}
});
deleteBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
contentResolver.delete(uri,"_ID=?",new String[]{"2"});
}
});
updateBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ContentValues contentValues = new ContentValues();
contentValues.put("name","鬼迷心竅");
contentValues.put("song","明明對你念念不忘，無法深藏，愛沒愛過想聽你講");
contentResolver.update(uri,contentValues,"_ID=?",new String[]{"4"});
}
});
queryBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Cursor cursor = contentResolver.query(uri,null,null,null,null);
SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),android.R.layout.activity_list_item,cursor,new String[]{"song"},new int[]{android.R.id.text1});
songList.setAdapter(adapter);
// cursor.close();
}
});
contentResolver.registerContentObserver(uri,true,personObserver);
}
private void queryDb(){
Cursor cursor = getContentResolver().query(uri,null,null,null,null);
SimpleCursorAdapter adapter = new SimpleCursorAdapter(getApplicationContext(),android.R.layout.activity_list_item,cursor,new String[]{"song"},new int[]{android.R.id.text1});
songList.setAdapter(adapter);
}
public class PersonObserver extends ContentObserver{
public PersonObserver(Handler handler){
super(handler);
}
@Override
public void onChange(boolean selfChange) {
super.onChange(selfChange);
queryDb();
}
}
@Override
protected void onDestroy() {
super.onDestroy();
getContentResolver().unregisterContentObserver(personObserver);
}
}
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