1 /* 2 * Copyright (C) 2017 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 17 package com.googlecode.android_scripting.service; 18 19 import android.annotation.TargetApi; 20 import android.os.Bundle; 21 import android.os.Handler; 22 import android.os.HandlerThread; 23 import android.os.Message; 24 import android.os.RemoteException; 25 26 import com.googlecode.android_scripting.Log; 27 import com.googlecode.android_scripting.jsonrpc.JsonRpcResult; 28 import com.googlecode.android_scripting.jsonrpc.RpcReceiverManager; 29 import com.googlecode.android_scripting.jsonrpc.RpcReceiverManagerFactory; 30 import com.googlecode.android_scripting.rpc.MethodDescriptor; 31 32 import org.json.JSONException; 33 import org.json.JSONObject; 34 35 /** 36 * Class responsible for Handling messages that came through the FacadeService 37 * interface. 38 * <br> 39 * Please refer to {@link FacadeService} for details on how to use. 40 */ 41 @TargetApi(3) 42 public class MessageHandler extends Handler { 43 44 private static final int SL4A_ACTION = 0; 45 private static final int DEFAULT_SENDING_ID = 0; 46 47 // Android sets this to -1 when the message is not sent by a Messenger. 48 // see http://developer.android.com/reference/android/os/Message.html#sendingUid 49 private static final int DEFAULT_UNSET_SENDING_ID = 1; 50 51 // Keys for the Bundles. 52 private static final String SL4A_METHOD = "sl4aMethod"; 53 private static final String SL4A_RESULT = "sl4aResult"; 54 55 private final RpcReceiverManagerFactory mRpcReceiverManagerFactory; 56 MessageHandler(HandlerThread handlerThread, RpcReceiverManagerFactory rpcReceiverManagerFactory)57 public MessageHandler(HandlerThread handlerThread, 58 RpcReceiverManagerFactory rpcReceiverManagerFactory) { 59 super(handlerThread.getLooper()); 60 this.mRpcReceiverManagerFactory = rpcReceiverManagerFactory; 61 } 62 63 /** 64 * Handles messages for the service. It does this via the same mechanism used 65 * for RPCs through RpcManagers. 66 * 67 * @param message The message that contains the method and parameters to 68 * execute. 69 */ 70 @Override handleMessage(Message message)71 public void handleMessage(Message message) { 72 Log.d("Handling Remote request"); 73 int senderId = message.sendingUid == DEFAULT_UNSET_SENDING_ID ? 74 DEFAULT_SENDING_ID : message.sendingUid; 75 if (message.what == SL4A_ACTION) { 76 RpcReceiverManager receiverManager; 77 if (mRpcReceiverManagerFactory.getRpcReceiverManagers().containsKey(senderId)) { 78 receiverManager = mRpcReceiverManagerFactory.getRpcReceiverManagers().get(senderId); 79 } else { 80 receiverManager = mRpcReceiverManagerFactory.create(senderId); 81 } 82 Bundle sl4aRequest = message.getData(); 83 String method = sl4aRequest.getString(SL4A_METHOD); 84 if (method == null || "".equals(method)) { 85 Log.e("No SL4A method specified on the Bundle. Specify one with " 86 + SL4A_METHOD); 87 return; 88 } 89 MethodDescriptor rpc = receiverManager.getMethodDescriptor(method); 90 if (rpc == null) { 91 Log.e("Unknown RPC: \"" + method + "\""); 92 return; 93 } 94 try { 95 Log.d("Invoking method " + rpc.getName()); 96 Object result = rpc.invoke(receiverManager, sl4aRequest); 97 // Only return a result if we were passed a Messenger. Otherwise assume 98 // client did not care for the response. 99 if (message.replyTo != null) { 100 Message reply = Message.obtain(); 101 Bundle sl4aResponse = new Bundle(); 102 putResult(senderId, result, sl4aResponse); 103 reply.setData(sl4aResponse); 104 message.replyTo.send(reply); 105 } 106 } catch (RemoteException e) { 107 Log.e("Could not send reply back to client", e); 108 } catch (Throwable t) { 109 Log.e("Exception while executing sl4a method", t); 110 } 111 } 112 } 113 putResult(int id, Object result, Bundle reply)114 private void putResult(int id, Object result, Bundle reply) { 115 JSONObject json; 116 try { 117 if (result instanceof Throwable) { 118 json = JsonRpcResult.error(id, (Throwable) result); 119 } else { 120 json = JsonRpcResult.result(id, result); 121 } 122 } catch (JSONException e) { 123 // There was an error converting the result to JSON. This shouldn't 124 // happen normally. 125 Log.e("Caught exception when filling JSON result.", e); 126 reply.putString(SL4A_RESULT, e.toString()); 127 return; 128 } 129 Log.d("Returning result: " + json.toString()); 130 reply.putString(SL4A_RESULT, json.toString()); 131 } 132 } 133