Java tutorial
package co.rewen.statex; /** * Copyright (c) 2015-present, Junjun Deng * Copyright (c) 2015-present, Facebook, Inc. * All rights reserved. * <p> * This source code is licensed under the BSD-style license found in the * LICENSE file in the root directory of this source tree. An additional grant * of patent rights can be found in the PATENTS file in the same directory. */ import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteStatement; import android.net.Uri; import android.support.v4.content.LocalBroadcastManager; import com.facebook.common.logging.FLog; import com.facebook.react.bridge.Arguments; import com.facebook.react.bridge.Callback; import com.facebook.react.bridge.GuardedAsyncTask; import com.facebook.react.bridge.ReactApplicationContext; import com.facebook.react.bridge.ReactContextBaseJavaModule; import com.facebook.react.bridge.ReactMethod; import com.facebook.react.bridge.ReadableArray; import com.facebook.react.bridge.WritableArray; import com.facebook.react.bridge.WritableMap; import com.facebook.react.common.ReactConstants; import com.facebook.react.common.SetBuilder; import com.facebook.react.modules.common.ModuleDataCleaner; import java.util.ArrayList; import java.util.HashSet; import static co.rewen.statex.StateXDatabaseSupplier.KEY_COLUMN; import static co.rewen.statex.StateXDatabaseSupplier.TABLE_STATE; import static co.rewen.statex.StateXDatabaseSupplier.VALUE_COLUMN; public final class StateXModule extends ReactContextBaseJavaModule implements ModuleDataCleaner.Cleanable { // SQL variable number limit, defined by SQLITE_LIMIT_VARIABLE_NUMBER: // https://raw.githubusercontent.com/android/platform_external_sqlite/master/dist/sqlite3.c private static final int MAX_SQL_KEYS = 999; private StateXDatabaseSupplier mStateXDatabaseSupplier; private boolean mShuttingDown = false; public StateXModule(ReactApplicationContext reactContext) { super(reactContext); mStateXDatabaseSupplier = new StateXDatabaseSupplier(reactContext); } @Override public String getName() { return "StateX"; } @Override public void initialize() { super.initialize(); mShuttingDown = false; } @Override public void onCatalystInstanceDestroy() { mShuttingDown = true; } @Override public void clearSensitiveData() { // Clear local storage. If fails, crash, since the app is potentially in a bad state and could // cause a privacy violation. We're still not recovering from this well, but at least the error // will be reported to the server. clear(new Callback() { @Override public void invoke(Object... args) { if (args.length == 0) { FLog.d(ReactConstants.TAG, "Cleaned StateX."); return; } // Clearing the database has failed, delete it instead. if (mStateXDatabaseSupplier.deleteDatabase()) { FLog.d(ReactConstants.TAG, "Deleted Local Database StateX."); return; } // Everything failed, crash the app throw new RuntimeException("Clearing and deleting database failed: " + args[0]); } }); } /** * Given an array of keys, this returns a map of (key, value) pairs for the keys found, and * (key, null) for the keys that haven't been found. */ @ReactMethod public void multiGet(final ReadableArray keys, final Callback callback) { if (keys == null) { callback.invoke(AsyncStorageErrorUtil.getInvalidKeyError(null), null); return; } new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null), null); return; } String[] columns = { KEY_COLUMN, VALUE_COLUMN }; HashSet<String> keysRemaining = SetBuilder.newHashSet(); WritableArray data = Arguments.createArray(); for (int keyStart = 0; keyStart < keys.size(); keyStart += MAX_SQL_KEYS) { int keyCount = Math.min(keys.size() - keyStart, MAX_SQL_KEYS); Cursor cursor = mStateXDatabaseSupplier.get().query(TABLE_STATE, columns, AsyncLocalStorageUtil.buildKeySelection(keyCount), AsyncLocalStorageUtil.buildKeySelectionArgs(keys, keyStart, keyCount), null, null, null); keysRemaining.clear(); try { if (cursor.getCount() != keys.size()) { // some keys have not been found - insert them with null into the final array for (int keyIndex = keyStart; keyIndex < keyStart + keyCount; keyIndex++) { keysRemaining.add(keys.getString(keyIndex)); } } if (cursor.moveToFirst()) { do { WritableArray row = Arguments.createArray(); row.pushString(cursor.getString(0)); row.pushString(cursor.getString(1)); data.pushArray(row); keysRemaining.remove(cursor.getString(0)); } while (cursor.moveToNext()); } } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); callback.invoke(AsyncStorageErrorUtil.getError(null, e.getMessage()), null); return; } finally { cursor.close(); } for (String key : keysRemaining) { WritableArray row = Arguments.createArray(); row.pushString(key); row.pushNull(); data.pushArray(row); } keysRemaining.clear(); } callback.invoke(null, data); } }.execute(); } /** * Inserts multiple (key, value) pairs. If one or more of the pairs cannot be inserted, this will * return StateXFailure, but all other pairs will have been inserted. * The insertion will replace conflicting (key, value) pairs. */ @ReactMethod public void multiSet(final ReadableArray keyValueArray, final Callback callback) { if (keyValueArray.size() == 0) { callback.invoke(AsyncStorageErrorUtil.getInvalidKeyError(null)); return; } new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null)); return; } String sql = "INSERT OR REPLACE INTO " + TABLE_STATE + " VALUES (?, ?);"; SQLiteStatement statement = mStateXDatabaseSupplier.get().compileStatement(sql); WritableMap error = null; ArrayList<String> keys = new ArrayList<>(); try { mStateXDatabaseSupplier.get().beginTransaction(); for (int idx = 0; idx < keyValueArray.size(); idx++) { if (keyValueArray.getArray(idx).size() != 2) { error = AsyncStorageErrorUtil.getInvalidValueError(null); break; } String key = keyValueArray.getArray(idx).getString(0); if (key == null) { error = AsyncStorageErrorUtil.getInvalidKeyError(null); break; } String value = keyValueArray.getArray(idx).getString(1); if (value == null) { error = AsyncStorageErrorUtil.getInvalidValueError(null); break; } keys.add(key); statement.clearBindings(); statement.bindString(1, key); statement.bindString(2, value); statement.execute(); } mStateXDatabaseSupplier.get().setTransactionSuccessful(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } finally { try { mStateXDatabaseSupplier.get().endTransaction(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); if (error == null) { error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } } } if (error != null) { callback.invoke(error); } else { callback.invoke(); notifyStateChanged(keys); } } }.execute(); } /** * Removes all rows of the keys given. */ @ReactMethod public void multiRemove(final ReadableArray keys, final Callback callback) { if (keys.size() == 0) { callback.invoke(AsyncStorageErrorUtil.getInvalidKeyError(null)); return; } new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null)); return; } WritableMap error = null; try { mStateXDatabaseSupplier.get().beginTransaction(); for (int keyStart = 0; keyStart < keys.size(); keyStart += MAX_SQL_KEYS) { int keyCount = Math.min(keys.size() - keyStart, MAX_SQL_KEYS); mStateXDatabaseSupplier.get().delete(TABLE_STATE, AsyncLocalStorageUtil.buildKeySelection(keyCount), AsyncLocalStorageUtil.buildKeySelectionArgs(keys, keyStart, keyCount)); } mStateXDatabaseSupplier.get().setTransactionSuccessful(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } finally { try { mStateXDatabaseSupplier.get().endTransaction(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); if (error == null) { error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } } } if (error != null) { callback.invoke(error); } else { callback.invoke(); notifyStateChanged(StateX.toStringArray(keys)); } } }.execute(); } /** * Given an array of (key, value) pairs, this will merge the given values with the stored values * of the given keys, if they exist. */ @ReactMethod public void multiMerge(final ReadableArray keyValueArray, final Callback callback) { new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null)); return; } WritableMap error = null; ArrayList<String> keys = new ArrayList<>(); try { mStateXDatabaseSupplier.get().beginTransaction(); for (int idx = 0; idx < keyValueArray.size(); idx++) { if (keyValueArray.getArray(idx).size() != 2) { error = AsyncStorageErrorUtil.getInvalidValueError(null); return; } String key = keyValueArray.getArray(idx).getString(0); if (key == null) { error = AsyncStorageErrorUtil.getInvalidKeyError(null); return; } else { keys.add(key); } if (keyValueArray.getArray(idx).getString(1) == null) { error = AsyncStorageErrorUtil.getInvalidValueError(null); return; } if (!AsyncLocalStorageUtil.mergeImpl(mStateXDatabaseSupplier.get(), key, keyValueArray.getArray(idx).getString(1))) { error = AsyncStorageErrorUtil.getDBError(null); return; } } mStateXDatabaseSupplier.get().setTransactionSuccessful(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } finally { try { mStateXDatabaseSupplier.get().endTransaction(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); if (error == null) { error = AsyncStorageErrorUtil.getError(null, e.getMessage()); } } } if (error != null) { callback.invoke(error); } else { callback.invoke(); notifyStateChanged(keys); } } }.execute(); } /** * Clears the database. */ @ReactMethod public void clear(final Callback callback) { new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!mStateXDatabaseSupplier.ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null)); return; } try { mStateXDatabaseSupplier.get().delete(TABLE_STATE, null, null); callback.invoke(); } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); callback.invoke(AsyncStorageErrorUtil.getError(null, e.getMessage())); } } }.execute(); } /** * Returns an array with all keys from the database. */ @ReactMethod public void getAllKeys(final Callback callback) { new GuardedAsyncTask<Void, Void>(getReactApplicationContext()) { @Override protected void doInBackgroundGuarded(Void... params) { if (!ensureDatabase()) { callback.invoke(AsyncStorageErrorUtil.getDBError(null), null); return; } WritableArray data = Arguments.createArray(); String[] columns = { KEY_COLUMN }; Cursor cursor = mStateXDatabaseSupplier.get().query(TABLE_STATE, columns, null, null, null, null, null); try { if (cursor.moveToFirst()) { do { data.pushString(cursor.getString(0)); } while (cursor.moveToNext()); } } catch (Exception e) { FLog.w(ReactConstants.TAG, e.getMessage(), e); callback.invoke(AsyncStorageErrorUtil.getError(null, e.getMessage()), null); return; } finally { cursor.close(); } callback.invoke(null, data); } }.execute(); } /** * Verify the database is open for reads and writes. */ private boolean ensureDatabase() { return !mShuttingDown && mStateXDatabaseSupplier.ensureDatabase(); } private void notifyStateChanged(ArrayList<String> keys) { /*Intent intent = new Intent(StateX.ACTION_STATE_CHANGED); intent.putStringArrayListExtra(StateX.EXTRA_KEYS, keys);*/ LocalBroadcastManager broadcastManager = LocalBroadcastManager.getInstance(getReactApplicationContext()); for (String key : keys) { Intent intent = new Intent(StateX.ACTION_STATE_CHANGED); Uri uri = StateX.uriForKey(key); intent.setData(uri); broadcastManager.sendBroadcast(intent); } } }