Abhi1code

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"
    defaultConfig {
        applicationId "com.matr..."
        minSdkVersion 21
        targetSdkVersion 29
        versionCode 1

Abhi1code

package com.m...;

import org.webrtc.DataChannel;

public class CustomDataChannelObserver  implements DataChannel.Observer {

    public CustomDataChannelObserver(){
    }

    @Override

Abhi1code

package com.m...;

import com.mat...;

import org.webrtc.DataChannel;
import org.webrtc.IceCandidate;
import org.webrtc.MediaStream;
import org.webrtc.PeerConnection;
import org.webrtc.RtpReceiver;

Abhi1code

package com.matrixf...n;

import org.webrtc.SdpObserver;
import org.webrtc.SessionDescription;

public class CustomSdpObserver implements SdpObserver {

    public CustomSdpObserver(){
        
    }

Abhi1code

peerConnection = peerConnectionFactory.createPeerConnection(rtcConfig, new CustomPeerConnectionObserver() {

            @Override
            public void onIceCandidate(IceCandidate iceCandidate) {
                super.onIceCandidate(iceCandidate);
                // 
            }

            @Override
            public void onDataChannel(DataChannel dataChannel) {

Abhi1code

public void setIceCandidate(String candidate, String sdpmid, int sdpmlineIndex){
        
        peerConnection.addIceCandidate(new IceCandidate(sdpmid, sdpmlineIndex, candidate));
        
}

Abhi1code

DataChannel.Init dcInit = new DataChannel.Init();
dataChannel = peerConnection.createDataChannel("1", dcInit);
dataChannel.registerObserver(new CustomDataChannelObserver(){

            @Override
            public void onMessage(DataChannel.Buffer buffer) {
                super.onMessage(buffer);
                // will be called when message is received from another peer
            }
});

Abhi1code

public void initialize(){

        PeerConnectionFactory.InitializationOptions initializationOptions =
                PeerConnectionFactory.InitializationOptions.builder(context)
                        .createInitializationOptions();
        PeerConnectionFactory.initialize(initializationOptions);

        PeerConnectionFactory.Options options = new PeerConnectionFactory.Options();
        peerConnectionFactory = PeerConnectionFactory.builder().setOptions(options)
                .createPeerConnectionFactory();

Abhi1code

public void createOffer(){
        
        peerConnection.createOffer(new CustomSdpObserver(){

            @Override
            public void onCreateSuccess(SessionDescription sessionDescription) {
                super.onCreateSuccess(sessionDescription);
                
                peerConnection.setLocalDescription(new CustomSdpObserver(), sessionDescription);
                // sessionDescription.description is string which needs to the shared across network

Abhi1code

public void createAnswer(){
        
        peerConnection.createAnswer(new CustomSdpObserver(){

            @Override
            public void onCreateSuccess(SessionDescription sessionDescription) {
                super.onCreateSuccess(sessionDescription);
                
                peerConnection.setLocalDescription(new CustomSdpObserver(), sessionDescription);
                // sessionDescription.description is string which needs to the shared across network