How to get expiry date for Subscription with client side in Android?

To Get Subscription Expiry date after subscription, need to follow below steps.

Step 1: First Get "mRefreshToken" from following api Google Publisher API

Step 2: Next need to get "access_tokon" using params("mRefreshToken", "client_id" and "client_secret") and below api.

final StringRequest mStringRequest = new StringRequest(Request.Method.POST, "https://accounts.google.com/o/oauth2/token",
    new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            [From response -get access_tokon]
        }
    }, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
        error.printStackTrace();
   }}) {
@Override
protected Map<String, String> getParams() {

    Map<String, String> params = new HashMap<>();
    params.put("grant_type", "refresh_token");
    params.put("client_id", "your_client_id");
    params.put("client_secret", "your_client_secret");
    params.put("refresh_token", mRefreshToken);

    return params;
}};

Step 3: You have "accessToken" from above api, after that get expiry json using below api and params

String url = "https://www.googleapis.com/androidpublisher/v2/applications/" + AppController.getInstance().getPackageName() + "/purchases/subscriptions/" + mSubscriptionId + "/" + "tokens/" + mPurchaseToken;

 final StringRequest mStringRequest = new StringRequest(Request.Method.GET, url, new Response.Listener<String>() {

        @Override
        public void onResponse(String response) {
            [From response -get expiry detail json]
        }
    }, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
    error.printStackTrace();
}}) {

@Override
public Map<String, String> getHeaders() throws AuthFailureError {

    Map<String, String> params = new HashMap<>();
    params.put("Authorization", "Bearer " + accessToken);
    return params;
}};

For more reference: official document url from Google "https://developers.google.com/android-publisher/api-ref/purchases/subscriptions/get" and "https://developers.google.com/android-publisher/authorization"