How get the information though Facebook Integration 

 //Gradle File
implementation'com.facebook.android:facebook-android-sdk:4.20.0'

//Declare In Manifest file
<meta-data
        android:name="com.facebook.sdk.ApplicationId"
        android:value="@string/facebook_app_id"/>
//End


//OnCreate
        callbackManager=CallbackManager.Factory.create();
//End

//Use this in click event and getting the information.      LoginManager.getInstance().logInWithReadPermissions(LoginActivity.this,Arrays.asList("public_profile","email"));
        LoginManager.getInstance().registerCallback(callbackManager,
        new FacebookCallback<LoginResult>(){
@Override
public void onSuccess(final LoginResult loginResult){
        Toast.makeText(LoginActivity.this,"Please wait",Toast.LENGTH_SHORT).show();
        Log.d(">>","User ID: "+
        loginResult.getAccessToken().getUserId());
        GraphRequest request=GraphRequest.newMeRequest(loginResult.getAccessToken(),new GraphRequest.GraphJSONObjectCallback(){
@Override
public void onCompleted(JSONObject object,GraphResponse response){
        try{
        facebookEmail=object.getString("email");
        name=object.getString("name");
        Log.i(">>facebookLoginResults",object.getString("email")+object.getString("name")+
        loginResult.getAccessToken().getUserId());
        }catch(Exception e){
        Log.i(">>facebookLogin","onCompleted: "+e.getMessage());
        }
        }
        });
        Bundle parameters=new Bundle();
        parameters.putString("fields","email,name");
        request.setParameters(parameters);
        request.executeAsync();
        }

@Override
public void onCancel(){
        Toast.makeText(LoginActivity.this,"Login Cancel",Toast.LENGTH_SHORT).show();
        Log.i(">>facebookLogin","cancel: "+"");
        }

@Override
public void onError(FacebookException exception){
        Toast.makeText(LoginActivity.this,"Login Error",Toast.LENGTH_SHORT).show();
        Log.i(">>facebookLogin","error: ");
        }
        });
        .build();
//End