The Demo introduces how to use the Carrier of Elastos’s Android SDK to achieve communication between phones and realizes a simple version of Chat Dapp.
Download android.sdk-debug.tar.gz from the following website and unzip it, add the extracted files to the app lib path:
https://github.com/elastos/Elastos.NET.Carrier.Android.SDK
The loaded directory structure is as follows:
localhost:libs xuxinlai$ pwd
/Users/xuxinlai/blockchain/Elastos.NET.Carrier.Android.Demo/app/libs
localhost:libs xuxinlai$ tree
.
├── arm64-v8a
│ └── libcarrierjni.so
├── armeabi
│ └── libcarrierjni.so
├── armeabi-v7a
│ └── libcarrierjni.so
└── elacarrier.jar
If you have not yet installed NDK, refer to the Android official website to install NDK and add the following configuration in the build.gradle file:
ndk {
moduleName "carrierjni"
ldLibs "log"
abiFilters "armeabi"
}
sourceSets {
main {
jniLibs.srcDirs = ['libs']
}
}
Before you initialize Carrier, you need to set the related parameters options and handlers, which are an instance of the following classes, respectively.
//1.Initialize the Carrier and get the related information
try {
//1.1 Initialize the Instance
carrierInst = Carrier.getInstance(options, handler);
//1.2 get the Carrier address
carrierAddr = carrierInst.getAddress();
Log.i(TAG,"address: " + carrierAddr);
//1.3 get the Carrier user id
carrierUserID = carrierInst.getUserId();
Log.i(TAG,"userID: " + carrierUserID);
//1.4 start the net
carrierInst.start(1000);
handler.synch.await();
Log.i(TAG,"carrier client is ready now");
} catch (ElastosException e) {
e.printStackTrace();
}
Don't forget to add related permissions in file AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET"/>
Add a friend by calling the function below:，
//2.1 add the friends
try {
Log.i(TAG,"start add Frind");
carrierInst.addFriend(friendAddr, "auto-accepted");
Log.i(TAG,"end add Frind");
}catch (ElastosException e) {
e.printStackTrace();
}
carrier.AcceptFriend(String friendId) function through overwrite the callback function onFriendConnection as below:
//2.2 verify the friends
public void onFriendRequest(Carrier carrier, String userId, UserInfo info, String hello) {
try {
if (hello.equals("auto-accepted")) {
carrier.AcceptFriend(userId);
}
} catch (Exception e) {
e.printStackTrace();
}
}
send Message to friends by the function sendFriendMessage
//3.1 send the message
try {
Log.i(TAG,"start send message");
carrierInst.sendFriendMessage("3uHutUcGb9Sc2VX87bwxuoejX7oDFRc2FuUkyYHxbNpG", "hello e");
Log.i(TAG,"end send message");
}catch (ElastosException e) {
e.printStackTrace();
}
receive the message by the onFriendMessage callback function as below:
//3.2 get the messsage from frined
public void onFriendMessage(Carrier carrier,String fromId, String message) {
Log.i(CALLBACK,"address:" + fromId + "connection changed to: " + message);
}