1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.android.managedprovisioning.common; 17 18 import android.content.BroadcastReceiver; 19 import android.content.Context; 20 import android.content.Intent; 21 import android.content.IntentFilter; 22 import androidx.annotation.Nullable; 23 import android.util.Log; 24 25 import java.util.concurrent.ArrayBlockingQueue; 26 import java.util.concurrent.BlockingQueue; 27 import java.util.concurrent.TimeUnit; 28 29 /** 30 * A receiver that allows caller to wait for the broadcast synchronously. Notice that you should not 31 * reuse the instance. Usage is typically like this: 32 * <pre> 33 * BlockingBroadcastReceiver receiver = new BlockingBroadcastReceiver(context, "action"); 34 * try { 35 * receiver.register(); 36 * Intent intent = receiver.awaitForBroadcast(); 37 * // assert the intent 38 * } finally { 39 * receiver.unregisterQuietly(); 40 * } 41 * </pre> 42 */ 43 public class BlockingBroadcastReceiver extends BroadcastReceiver { 44 private static final String TAG = "BlockingBroadcast"; 45 46 private static final int DEFAULT_TIMEOUT_SECONDS = 10; 47 48 private final BlockingQueue<Intent> mBlockingQueue; 49 private final String mExpectedAction; 50 private final Context mContext; 51 BlockingBroadcastReceiver(Context context, String expectedAction)52 public BlockingBroadcastReceiver(Context context, String expectedAction) { 53 mContext = context; 54 mExpectedAction = expectedAction; 55 mBlockingQueue = new ArrayBlockingQueue<>(1); 56 } 57 58 @Override onReceive(Context context, Intent intent)59 public void onReceive(Context context, Intent intent) { 60 if (mExpectedAction.equals(intent.getAction())) { 61 mBlockingQueue.add(intent); 62 } 63 } 64 register()65 public void register() { 66 mContext.registerReceiver(this, new IntentFilter(mExpectedAction)); 67 } 68 69 /** 70 * Wait until the broadcast and return the received broadcast intent. {@code null} is returned 71 * if no broadcast with expected action is received within 10 seconds. 72 */ awaitForBroadcast()73 public @Nullable Intent awaitForBroadcast() { 74 try { 75 return mBlockingQueue.poll(DEFAULT_TIMEOUT_SECONDS, TimeUnit.SECONDS); 76 } catch (InterruptedException e) { 77 Log.e(TAG, "waitForBroadcast get interrupted: ", e); 78 } 79 return null; 80 } 81 82 /** 83 * Wait until the broadcast and return the received broadcast intent. {@code null} is returned 84 * if no broadcast with expected action is received within the given timeout. 85 */ awaitForBroadcast(long timeoutMillis)86 public @Nullable Intent awaitForBroadcast(long timeoutMillis) { 87 try { 88 return mBlockingQueue.poll(timeoutMillis, TimeUnit.MILLISECONDS); 89 } catch (InterruptedException e) { 90 Log.e(TAG, "waitForBroadcast get interrupted: ", e); 91 } 92 return null; 93 } 94 unregisterQuietly()95 public void unregisterQuietly() { 96 try { 97 mContext.unregisterReceiver(this); 98 } catch (Exception ex) { 99 Log.e(TAG, "Failed to unregister BlockingBroadcastReceiver: ", ex); 100 } 101 } 102 } 103