Accessing Oracle Mobile Cloud Service (MCS) REST from Postman

Do you want to test in your environment REST service running on Oracle MCS cloud? I have implemented public REST service hosted on Oracle MCS, you can call it from Postman application (Google Chrome extension).

Implemented use case - SOAP Connector in MCS is reading Stock Quote information for the company supplied in the request. Information is transformed by MCS Custom API (with Node.js) into REST structure and returned to the client through MCS Mobile backend.

Here is the REST GET url to invoke in Postman: https://mobileportalsetrial1304dev-mcsdem0001.mobileenv.us2.oraclecloud.com:443/mobile/custom/STOCKQUOTE_API_REDSAMURAI_BLOG_1/stockquote/ORCL. Try to run it, you can replace ORCL with another company ID. To execute this REST request in Postman, you need to provide configuration file (this allows to call MCS). Configuration file can be downloaded from here - Postman_MCS_1.json. This file contains all required info to make REST request from Postman:

To add configuration file to Postman, go to Configuration and upload it through Import data option:

Make sure MCS profile is selected:

When you copy paste REST URL, go to Headers section and select MCS from Presets - this will add two required headers:

You should see company stock information returned back from REST call:

Let's switch to MCS. There are three main concepts in MCS - Mobile Backend, custom API, Connector. Mobile Backend is a service interface, it allows to configure mobile access functionality and contains a list of Web Services (API's) exposed to the clients. It allows to track service usage and view statistics in the dashboard:

My example contains single Web Service (custom API). This service is responsible to handle REST GET method and return company stock quote data:

Custom API defines REST resource /stockquote/{company}, this is what we are executing in Postman URL:

Resource /stockquote/{company} is configured with GET method:

GET method is configured to handle two type of responses - 200 (OK) and 404 (Not Found):

To provide API implementation (mapping between Connector and API response), we can download (see example - stockquote_api_redsamurai_blog_1.zip) Node.js file from MCS and edit it locally (edited file can be uploaded back in the archive):

We need to specify Connector name to be available in Node.js, this is how it will call Web Service defined in the Connector:

Node.js function is responsible to call Web Service from Connector, pass parameter and check the result (here you can do complex transformations between SOAP and REST):

I'm using SOAP connector, pointing to external Web Service to fetch Stock Quote information for the company:

Oracle Mobile Cloud Service - External SOAP Service Connector

These days everything is about MCS/MAF. I'm also looking into this new area, but I'm trying to mix traditional ADF topics and new things. Who knows may be MCS/MAF is a new big thing and its good time to learn it. I was testing how it works to define my own custom SOAP connector to calculate currency conversion rate.

MCS developer portal allows to create and use new connector. Special wizard helps to complete this task, just click on large CONNECTORS icon:

There is new option available to create new SOAP/REST connector:

Wizard reminds me JDEV interface, steps are similar as to generate SOAP connection in JDEV. You need to provide SOAP WSDL URL, name and description:

If create action is successful, General step is displayed with SOAP connector general details:

Port step provides information required when you would like to call SOAP service through the connector in custom code:

There is no security and in the last step I can test it. I'm checking for conversion rate from EUR to USD in the payload. Mobile backend should be specified to test connector SOAP call. I would understand Mobile backend something like Application Module in ADF BC, it is required to group business logic and expose interface:

SOAP service is invoked and I can see the response:

Connector is tested through mobile backend. Later in the diagnostics section we could see invocation statistics:

Next step would be to include connector call into custom API.

Oracle Mobile Cloud Service First Hands-On Experience

Thanks to SOA Community and Jurgen Kress, I had a chance to play with Oracle MCS (Mobile Cloud Service). This new Oracle product is promoted with full force by Oracle PM team, there is dedicated Youtube channel with videos to watch and learn - Oracle Mobile Platform. Mobile Cloud Service offers mobile enterprise repository to organize and support your mobile development. Mobile backend services, security, connectors, storage and etc. can be defined and managed in MCS. Web Services published in MCS can be monitored to track performance and errors. All this should simplify mobile solutions implementation.

This was my first encounter with MCS and I would like to describe the test I did. MCS UI is implemented with Oracle internal JS framework following Alta UI standard. There are options to monitor and administer MCS instance. I'm more interested in development options:

I will not go through all available options, but only focus on Mobile Backend. Basically we can define a group, where we could include various reusable business logic artefacts (API's). Mainly this will be different Web Service calls. The same Web Service calls can be reused by mobile application developer.

In Mobile Backend section we can edit existing groups or create a new one:

You should think about Mobile Backend as about a group of reusable code artefacts (API's). There is an option to create new API or reuse existing one. I decided to reuse existing API for Incidents registration:

This API implements REST Web Service call to register new incident, also it allows to query information about previously reported incidents. This can be tested directly in MCS environment, we could define sample payload data and simulate Web Service call to register new incident:

Web Service call is successful, we can observe this from the log - new incident is registered and ID is assigned. Same Web Service will be reused from mobile application. With MCS we could monitor Web Service usage, number of invocations, errors, etc. - this makes it easier to manage entire infrastructure for mobile solutions:

To make sure new incident was successfully registered, I could run another REST call for the same Web Service - to get incident information about ID:

Result shows incident data, this means incident was located successfully:

Incidents registration service is registered in API's group, we could edit and test this Web Service online in MCS:

Red Samurai mobile backend service is live - invocation statistics and processing time metrics are aggregated by MCS:

WebSocket Accelerated Live Data Synchronization for MAF

New generation Mobile and Web applications are going to use WebSockets. This is one of the fastest and convenient ways to transfer JSON formatted data from the server to the client and back. Huge advantage - server could initiate data synchronisation request and deliver JSON messages directly to the client. You should read my previous post about detail information how to configure MAF with WebSocket - Oracle MAF and WebSockets Integration - Live Twitter Stream.

In this post I would like to describe, how to integrate further information received through WebSocket with MAF components. I will use MAF Tree Map UI component to display live data for Tweets locations.

Below you could see screen recording - MAF Tree Map is getting refreshed automatically, each time when update through WebSocket channel is being received. This is amazing, how fast data through WebSocket channel is coming. In this test, MAF is handling around 1 update per second, received from WebSocket:

Let's look how it is implement behind the scenes. There is MAF Tree Map UI component, this is regular MAF component to render graph visualisation:

UI component is based on Data Bindings, collection is initialized from Data Control method:

Method handling data update from WebSocket is responsible to update data collection - it invokes helper method, where data collection is re-constructed. Standard Refresh Provider is helping to repaint data displayed on the UI:

Simple and effective. Download sample application - AltaMobileApp_v2.zip.

Oracle MAF and WebSockets Integration - Live Twitter Stream

Oracle MAF and WebSockets - I will describe how it works together. WebSockets is a protocol providing full-duplex communication channel over a TCP connection. This channel is interactive (communication is both ways) and we can send messages from the server to the client (MAF application running on the device). There is no need to use push notifications, WebSockets provide JSON support and allow to send complex payload data. In a way it competes with REST, however REST is different with request is being initiated by the client. WebSockets data is received automatically - there is no need to trigger any event by the client.

I have implemented sample MAF application with WebSockets integration, you can download it here - AltaMobileApp_v1.zip. Finance screen in the application contains MAF output text component. This component displays latest data received through WebSockets channel. Server side is listening for live Twitter Stream updates and sends each tweet location over WebSockets to the MAF application. See how it works in this screen recording:

WebSockets communication is not blocking MAF application functionality, it runs in the separate thread. User can navigating between MAF screens, run different actions and WebSockets delivers data in parallel.

Sample applications is based on two parts - server side WebSockets implementation with Twitter Stream listener and client side MAF application with WebSockets client.

Twitter Stream is handled with Twitter4J API, JAR's are included with the sample. You would need to provide your own Twitter account details, access keys could be retrieved for your account from Twitter developer portal. Make sure to obtain these keys, before running sample application:

New message from Twitter Stream is received by listener method - onStatus. I'm listening for all the tweets around the world, related to corporate keyword. Once there will be new tweet related to this topic, onStatus listener will be notified. In the listener method, I'm retrieving tweet location and and initiating WebSockets communication:

Method in WebSockets implementation - notifyClient, sends text message to the client (JSON message is supported as well):

Listener for Twitter Stream is started automatically, when application is deployed. This is done through servlet initialisation:

On the client side - MAF application is configured to receive automatic notifications through WebSockets channel. Implementation for WebSockets listener is very similar with the regular ADF Faces - it is done through JavaScript. MAF feature is registered with JavaScript file:

JavaScript contains all required methods for WebSockets communication. Here we open WebSockets channel with connectSocket function and further listen for the new messages/notifications with onMessage method. My goal is to update MAF components with the new data received through WebSockets. For this reason, I'm invoking Java method from onMessage JavaScript function and passing payload data (recently received tweet location):

Invoked Java method - processWebSocketMessage is responsible to update MAF bindings with the new data. Data Bindings class contains standard MAF propertyListener implementation, which ensures data refresh on MAF UI:

MAF output text on the UI displays recent data received through WebSockets channel:

Indicator for Background REST Service Access with A-Team Mobile Persistence Accelerator

You should check my previous post about Background REST Service Access with A-Team Mobile Persistence Accelerator (AMPA). There I describe how to optimise MAF performance for REST service calls, allow user to continue working with the mobile application, without locking the screen until Web Service response arrives. Steven Davelaar have documented how it works, you can read it in his blog - Calling Web Services in Background Using MAF 2.1.

I have updated sample application from previous post, to include indicator for AMPA background service call status tracking. Updated sample application - MobileServiceBusApp_v8.zip.

AMPA provides application scope variable, which acts as a flag and indicates when background service call is executed. Based on this flag, we could conditionally display animated GIF image, this will help user to understand if background service call still runs:

When user is searching and request is being processed in background, he will see rotating status indicator in the top right corner:

Until data is being returned from background task, user could go to another screen and monitor when request is completed, to see the latest data:

Once background task completes, indicator disappears:

Background REST Service Access with A-Team Mobile Persistence Accelerator

REST service transfers light data, but service execution time could bring significant delay to the enterprise mobile application. I have already introduced you to the A-Team Mobile Persistence Accelerator (AMPA) in previous post - REST Service Access with A-Team Mobile Persistence Accelerator. Based on AMPA author - Steven Davelaar suggestions, I will post today updated application, where REST service call will be handled in background. This will allow mobile user to continue working with the MAF application, while REST call is being processed in background thread.

Here you can download updated sample application - MobileServiceBusApp_v7.zip. Remote read in background is configurable through AMPA persistence mapping, I have changed it to be false - let's see how it works for slow REST service execution:

Data Control method is executing (sequential in this example) remote findAll operation through AMPA, to fetch employees data. Data collection is loaded to the UI, after service execution is completed:

Server side ADF BC VO is set to wait 30 seconds (waiting for 30 seconds after VO was executed), before completing SOAP response. This allows to simulate slow REST service execution and check how MAF mobile application behaves with sequential service call:

Executing search operation over slow REST operation blocks entire MAF mobile application. User can't navigate to other screens and is locked into current screen, until response comes. This is how it looks like, when I changed search criteria - mobile application waits for the response:

Obviously this is inappropriate, because it blocks application and user can't continue his work. Let's test with AMPA configured to execute REST calls in background - remoteReadInBackground = true:

Data Control method responsible to execute REST action is refactored. I'm only starting remote findAll operation - not waiting it to complete. AMPA generated service class EmployeeService is changed to include additional constructor, where I'm passing instance of Data Control class and a flag to prevent auto query. Here is applyFilter method from Data Control class, it call REST service in background, through AMPA:

AMPA generated class is changed with overriden method refreshEntityList. This method is called automatically by AMPA, when background REST call is completed. Here I'm calling Data Control class method, responsible to refresh UI and display data fetched from the background service:

Data Control class method responsible for UI refresh - it updates Data Control collection and invokes synch with UI:

I will describe a test I have completed, with REST service execution in background. Perform search action with a parameter:

ADF BC on server side executes VO with SQL statement, there is a wait time of 30 seconds:

MAF mobile application is not blocked anymore, as it was with sequential REST service execution. User can navigate to other screen and do different actions:

Once ADF BC VO completes execution and SOAP service returns response, Service Bus is transforming SOAP response to REST. Mobile application receives data and UI refresh happens, to present latest changes. User can view the changes, once he is back to the screen:

In the same way, user could run another search:

While search is running, user could view details for present data:

After returning back to the search list, results for the new search query are displayed - data from REST service call executed in background:

User could load details screen and view the data: