Spring WebFlux

Authentication & Session debugging

AuthenticationWebFilter

DefaultWebSessionManager

WebSessionServerSecurityContextRepository

OAuth2AuthorizationCodeGrantWebFilter

OAuth2AuthorizationRequestRedirectWebFilter

SpringSessionWebSessionStore

Creating sample flask application on heliohost.org

1. Follow the steps given in this blog and prepare the sample flask app. File structure should look as shown below:
   
   
   
2. Other file contents: 
   
   
   
3. You can access the application from this url https://svankamamidi.helioho.st/flask/ 

Logging in Spring Reactive streams (webflux)

 Refer https://www.baeldung.com/spring-log-webclient-calls#2-logging-with-netty-httpclient

Smart Actions - Intelligent applications

 Smart Actions such as:

1. may be in mailbox app, while scheduling a meeting provision to find an available room matching requested capacity and book it. This Smart Action should be available as type a head feature so that new user can also benefit from it. Also it should be visible in menu options.
• Currently user has to know how to lookup for conference rooms and see the available ones and book
• User may very well forget booking a conference room, so a reminder tooltip would be very useful
2. Next

Returning variable number of fields in resource GET request

In the GET call we can mention the required list of field names, including parent child hierarchies. 

GET /resource?fields=field1, field3, parent1.child2

Here additional effort is fields list has to be parsed and each field need to be mapped to DB Entity field. For this simple convention is you can use same field names as in DB Entity class in above GET request.

In some cases fields list in GET call may be too many and exceed the allowable URL size then  profiles or views approach can be used. A named view consists of predefined list of fields, so each view name defines a unique list of fields. Let’s say for discussion, our views are AsiaPac (consists of 20 fields), Euro (consists of 40 fields), Australia (consists of 30 fields) etc, i.e. unique list of Resource fields are tied to each view name based on the relevance; now if I request for AsiaPac view then I would be given 20 fields, for Euro 40 fields and for Australia 30 fields. So my API usage can be 

GET resource/123?viewName=Euro

We can even provide this view definition (fields list) as resource and we should be able to view, add, update and delete view based on need basis.

SQL Tips & Quirks

1. PL/SQL Anonymous block sample with DBMS_APPLICATION_INFO.set_module example & PL/SQL procedure invocation

Gangtok Tour

1. Rumtek Monastery 
2. Tsomgo or Changu Lake 
3. Ropeway: Awesome Cable Car Ride 
4. Ranka Monastery
5. Ban Jhakri Waterfall 
6. Hanuman Tok 
7. Saramsa Garden 
8. Ganesh Tok 
9. Do-Drul Chorten Stupa 
10. Tashi View Point
11. Enchey Monastery 
12. Bakthang Waterfall
13. Khangchendzonga Biosphere Reserve

References

1. https://www.darjeeling-tourism.com/darj_000101.htm

2. http://www.transindiatravels.com/sikkim/gangtok/tourist-places-to-visit-in-gangtok/

JS add on's in developing Single Page Applications

Below are the common additional JS utilities, plugins or functionalities you may need while developing Single Page Applications:

jsPDF

A very handy utility to generate PDF's at client side. 
Support for image types jpg and png is included.

fromHTML plugin does not render images which are part of table cells. You can  use jsPDF fork https://github.com/Flamenco/jsPDF to address the same.

Android Development Tips

1. How to access app files from internal storage
• adb shell
• run-as com.yourapp.package-name
• Now you can navigate to the app_<app_name> folder and go through the files.
2. Copy file from desktop to device sdcard
• adb push d:\temp\delnow\console.log /sdcard
3. Move file from sdcard to internal storage
• adb shell
• run-as com.sanjith.carcare
• mv /sdcard/console.log ./app_CarCare/.
4. Application log viewing
• adb logcat | findstr "com.example.app"
• adb -d logcat | findstr "com.example.app" > C:\file-path
5. Next

JAX-RS REST API Caching

How to use Scala along with Spark for a Java Developer

Below are tips and tricks I have learnt about Spark with Scala

1. How to create dataset of custom objects

   import spark.implicits._ class MyObj(val i: Int) // ... val d = spark.createDataset(Seq(new MyObj(1),new MyObj(2),new MyObj(3)))

   Will give you error, so instead use kyro encoder

   import spark.implicits._ class MyObj(val i: Int) implicit val myObjEncoder = org.apache.spark.sql.Encoders.kryo[MyObj]

   // ...
   

   val d = spark.createDataset(Seq(new MyObj(1),new MyObj(2),new MyObj(3)))

2. 
   
3. 
   

Health Benefits of Kefir I have seen personally!

Disclaimer: This is not any medical advice or prescription, please consult doctor for any health issues. These are authors personal observations.

1. Kefir drink is rich in B vitamins, enzymes which are essential for healthy individual.
2. Kefir drink is very beneficial for dental health  as the root cause of dental decay or any other dental problems are bad bacteria. Regular intake of water Kefir fermented with lemon or ginger improves the dental health a lot and also removes the bad breath from mouth.
3. Candida infections are cleared. Kefir is instrumental in removing candida infections by drinking regular water Kefir. It removes candida infections in mouth, private parts.
4. Tendency towards Alcohol is gone. Sugar craving is reduced and improved the responsible living attitude, I mean taking care of personal health.
5. Brightens the skin by regular application on skin.
6. Anti depressant, it inhibits the feel good feeling by boosting the serotonin production.
7. Solves several gut issues ranging from indigestion, acidity, constipation etc.
8. Diabetic patients need to be careful while using water kefir, as it may contain more sugars if not reduced by doing second fermentation. In my case regular drinking of second fermented drink has brought down my sugar levels to normal range. 

How to increase the growth of Kefir Grains?

If you want to increase the growth of Kefir grains you can do by adding mineral sources such as Baking Soda (only pinch of it, i.e. 1/16th of spoon) to the fermentation bottle. You can alternate it with organic Jaggery. Both are good sources of minerals; Jaggery contains molasses which is rich in minerals. Also do give just regular white sugar on few days.

While using jaggery make sure it is dissolved in the water otherwise Kefir cannot feed on it. Merchandises are selling the powdered jaggery also.

Kefir Grains need regular minerals as our water sources are mostly filtered and/or RO, so prolonged use of just RO water will deplete the Kefir health and content.

While using above mineral sources if Kefir grains and fermented liquid is turning slimy then it is clear indication that excess minerals are being fed. So you need to give them simple sugar liquid for few days until they become more crystalline. Also reduce the amounts of mineral sources. In case of jagerry you can use 50% jagerry and 50% plain sugar.

Everything you want to know about your Moto G4 Plus

Below are the various tips, tricks and how to's to use Moto G4 Plus efficiently and fully

1. How to take screenshot on Moto G4 Plus?
• For taking screenshot, follow the steps given below.
• Go to the screen on which you want to capture screenshot.
• Press and hold volume down and power button simultaneously.
• The screenshot will be taken and saved in the Gallery folder. You can access it from “File Manager” or from the “Photos” app from Google which are preinstalled on your Moto G4 Plus.
2. You can quick-load the camera with a double-tap of the power button, or a double-twist of your wrist.

References

1. http://www.tech2touch.com/moto-g4-plus-tips-tricks-faq/
2. http://www.digitaltrends.com/mobile/moto-g4-tips-and-tricks/
3. https://recombu.com/mobile/article/moto-g4-plus-camera-review-and-comparison-vs-moto-g4-camera#
4. http://www.trustedreviews.com/opinions/motorola-moto-g-tips-and-tricks

Kefir Articles

Below are list of various articles on water kefir which can help you to know more about water kefir and using it. If you have any questions about kefir or articles please feel free to ask here using comments section. 

 

How to prepare Water Kefir

FAQ on Water Kefir 

How to make Coconut Water Kefir

How to reduce sugar from water kefir (second fermentation!)

How did I made my wonderful Kefir Ginger Lemon drink

 

 

 

 

 

How to reduce sugar from water kefir (second fermentation!)

Water kefir is a wonderful probiotic drink, I have myself saw improvements in digestion and regular bowel moments. I have seen uplift in my confidence levels and seeing depression being faded away in just one week of regular drinking (3 spoons) of kefir once in bed time.

If you are diabetic or concerned about higher sugar content in the Kefir drink, I have seen second fermentation as best solution. My best choice is Ginger based second fermentation.

Procedure

1. Take a piece of Ginger, peel its skin and cut into 4 equal cubes. 
2. Drain the first fermentation liquid into glass jar and preserve the kefir grains into another fresh sugar water jar.
3. Add the prepared ginger cubes to this drained water kefir and close the jar lid tightly
4. Let it ferment for 24 hours and after that store it in fridge and use it for up to a week.
5. You can have around 30 ml of this drink along with glassful of water in the early morning and before bed in the night. 

More on Kefir here

How did I made my wonderful Kefir Ginger Lemon drink

What do you need

1. A cup of fermented water kefir
2. Take a 15 grams of ginger and peal the outer layer and cut into slices
3. Take one lemon

How to prepare

1. In glass bottle with kefir water mix ginger slices and squeeze cut lemon juice.
2. Tightly close the bottle and keep it in dark place, for every 6 to 10 hours burp the bottle by carefully opening the lid so that carbonation can be removed and then tightly close the lid.
3. This is called second fermentation of water kefir, keep this until you see enough bubbles in the bottle and not more than 24 hours to 36 hours.
4. Once ready you can mix sugar and some cold water and enjoy the drink. If you are first time drinker just start with one or two spoons drink and gradually increase it.
5. The drink should not have any strong odor or color.

More on Kefir here

How to make Coconut Water Kefir

Before using the Kefir grains for making coconut water Kefir make sure to prepare few batches of sugar water kefir so that Kefir grains are well hydrated and nourished. 

Preparation is as same as making Water Kefir drink.
1. Take 1 tender coconut water and 1 spoon of Kefir grains.
2. Use coconut water instead of sugar water and add the Kefir grains in to the bottle.
3. Depending on the temperature let it ferment for 10 to 12 hours.
4. Drain the fermented coconut water into a bottle and separate the grains, put the grains in to sugar water for next batch.
5. This bottled water you can refrigerate and drink for 1 day.

Rotate grains with sugar water and coconut water on alternate days as grains can't absorb sugars well from coconut water.

More on Kefir here

How to prepare Water Kefir

Kefir is a very good probiotic and is rich in enzymes, Vitamin B. Unlike yougurt its benefits last for more than one day.

Prerequisites

1. A glass bottle (size of fruit jam bottle) preferable with plastic lid.
2. Filter similar to tea filter, but of plastic.
3. Plastic or wooden spoon. Never bring Kefir grains or Kefir liquid in direct contact with metal utinsils.
4. Good quality white sugar (preferably with no preservatives)
5. Either good quality brown sugar, Jaggery, organic molasses
6. Baking Soda. It is not baking powder. It is also called Eating Soda in India.
7. A lemon

Preparation

Once you obtain the grains, place them in a glass jar with two tablespoons

of sugar. Add water until it is about 2-3 inches above the grains and store in

the fridge overnight. There is a lot of flexibility with how you prepare water

kefir, but the basic steps are as follows.

Step 1

Fill a glass jar with water, leaving a couple inches of headspace at the top.

For every 2-3 cups of water add a tablespoon of grains and a tablespoon or

two of sugar. You can use white sugar, brown sugar, molasses, etc.

Step 2

Stir with a wooden spoon until sugar is dissolved. If you want to add fruit at

this point, go ahead. You can also squeeze some lemon juice in.

Step 3

Cover the jar with a paper towel, or light cloth, so the mixture can breathe,

and store in a cool, dark place, like a cupboard for 7-12 hours depending on

room temperature and how strong you want it. On a hot summer day it

may be ready in as little as 7-8 hours.

How to consume it

After fermenting the Kefir grains with suagr and water solution for about 7-12 hours you can filter the liquid from grains. This liquid you can directly drink or can make non hot beverages such as lemonade by mixing lemon juice or some other fruit juice. You can store this liquid in fridge for 24 hours or a bit more.

When you are taking this drink for first time, start with less quantity like 1 or 2 spoons and then gradually increase in take.

While preparing for first time using starter culture, do not consume the finished liquid for first 3 to 4 days. Simply throw it and start next fermentation cycle by adding fresh sugar and water to the grains.

Precautions and Troubleshooting

1. Never expose Kefir grains or fermented solutions to heat, it will kill the Kefir.
2. During fermentation never keep the bottle directly exposed to sun light. 
3. During or after fermentation if Kefir liquid or grains color changes to blue or green then there could have been contamination during preparation so you need to discard whole batch i.e. liquid along with grains.
4. If you see any molds in the bottle then you have to discard whole batch.

Tips

1. Even after 10-12 hours of fermentation if your water kefir still tastes sugary then you can let it ferment for few more hours based on your local temperature. Kefir ferments slowly in cool temperature; moreover it should not be exposed to very hot temperatures also like summers, may be in such cases you can keep it in AC room.

FAQ

FAQ

Second Fermentation & Flavoring

Refer

More...
How to make Coconut water kefir?

More on Kefir here

FAQ on Water Kefir

1. What is the temperature to ferment the water kefir?

Answer: 25 Centigrade

2. With how many spoons of Kefir grains to start the first fermentation?
3. How many cups of water to be mixed with first Kefir fermentation batch?
4. How many spoons of sugar has to be added to first Kefir fermentation batch?

Answer: Two table spoons of Kefir grains to be mixed with 2 cups of water and 2 to 3 spoons of sugar. Need to dissolve entire sugar in to water using wooden spoon as metal kills the Kefir grains. 

5. How long to ferment
Answer: 10-12 hours
While starting with starter kit, for first 3-4 days give them fresh water and sugar for every 10-12 hours, so for every 10-12 hours drain the old liquid and add fresh water and sugar.

6. How long I can use the fermented Kefir drink?
Answer: 
Once the drink is ready, if you leave it for too long, it will become too pungent;
as soon as you find the taste to be palatable, consume it within 24 hours or less.

7. Once fermented Kefir liquid is ready, what to do with fresh grains after draining the Kefir liquid.

Answer: 
You can either freeze the extra grains without water and sugar
or
You can keep them in fridge in sugar, water solution and keep changing it every 5 to 6 days.

8. What type of water has to be used

Answer: Non chlorinated water has to be used

9. Should I have to ferment Kefir right after receiving the starter kit grains?

Answer: Yes, so that Kefir grains will adjust to the new environment.

10. Can I take few weeks break?
Answer: 
Yes, simply put the Kefir grains in white sugar and water solution and close the bottle lid tightly and keep it in fridge. You can leave it for up to 3 weeks.

11. How to restart after break?

12. When I can have the Kefir drink?
Answer: Any time of the day 

More on Kefir here

13. How to ferment Kefir in summer season
Answer: Refer this article