Android push notification using Parse Cloud Code

main.js

Parse.Cloud.define("push", function (request, response) {
  var query = new Parse.Query(Parse.Installation);
  query.equalTo("installationId", request.params.installationId);
  Parse.Push.send({
    where: query,
    data: request.params.data
  }, {
    useMasterKey: true,
    success: function () {
      response.success("Success!");
    },
    error: function (error) {
      response.error("Error! " + error.message);
    }
  });
});

PushNotification.java

String installationId = "INSTALLATION_ID"; // replace with correct installationId

Map<String, String> data = new HashMap<String, String>();
data.put("alert", "Hello there!"); // replace with correct message

Map<String, Object> params = new HashMap<String, Object>();
params.put("installationId", installationId);
params.put("data", data);

ParseCloud.callFunctionInBackground("push", params, new FunctionCallback<Object>() {
    @Override
    public void done(Object response, ParseException e) {
        if (e == null) {
            // push was sent
        }
    }
});