Noorul Hameed

Hi,

Node.js is running into Chrome API, which is Object-based system in approach. In contrast, Java EE servers and applications deploy OO services as well.

How does Node.js approach in various perspectives between object-oriented and object-based?

Thank you

Dear  Slobodan Stojanovic and Aleksandar Simovic,


As described, Payment Card Industry Standard (PCI) standards are implemented with Node.js among AWS Lambda, Microsoft's Azure, Google Cloud Foundation, and IBM Open Whisk.
AWS Lambda included aws-serverless-express in Node.js module. It created with HTTP services.

I ask general question about express.js module.

Does aws-serverless-express in Node.js module create OS service internally or works as serverless routines only?


Thank you

Dear Slobodan Stojanovic and Aleksandar Simovic,

Node.js used Claudia API Gateways between a browser request and AWS Lambda functions. It also discussed various services and routines to route event handlers.

In asynchronous form, it works as like AJAX XMLHttpRequest service used in JavaScript.
As a note, XMLHttpRequest can also be sent/received either synchronous or asynhronous manner. Have a at code as below.
var xhttp= new XMLHttpRequest(); xhttp.open("GET", "ajax_info.txt", false); xhttp.send();
Similiarly, xhttp.responseText used to get server response as stream.
Here I want to ask, Is it working for similiar functionaly as provided by JavaScript services using XMLHttpRequest functions?


Thank you

Dear Authors,

In connection with AWS Ecosystem, DynamoDB and NoSQL are embedded as simpler databases. The following example in book shows that table automatically specified with PRIMARY key only.

aws dynamodb create-table --table-name pizza-orders \   --attribute-definitions AttributeName=orderId,AttributeType=S \   --key-schema AttributeName=orderId,KeyType=HASH \   --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1 \  --region eu-central-1 \   --query TableDescription.TableArn --output text


Other fields are omitted too. Order table (i.e. pizza-orders) not specified with pizza, address and order status fields;  Is it auto assignments when it was runtime?

Thank You

Dear Slobodan Stojanovic and Aleksandar Simovic,

At first thing, I want to ask a question regarding the book sections that included in first chapter.

As show in the Pizza API (below), there are several files grouped into package. Similiarly, a data folder is being used to store static files and data in it. Currently, it uses pizzas.json.

What else can we place into [data folder] ? Is it for database oriented storage location or  general documents?

In addition to the above, Amazon S3 buckets only allows connection for a presigned URL; images and thumbnails. The both created under /tmp folder inside S3.

I want to get more information for the use of ImageMagick in image processing. The question will be. "Why would we use convert function as always to resize in thumbnails?"



Thank you

I am very happy to be here in this week's forum with Slobodan Stojanovic and Aleksandar Simovic.
Welcome authors!

Hello Everyone,

I have passed OCP EXAM 1Z0809 with 65% at today.
Thanks for JavaRanch and members.

Hi All,

Thank you for giving me this great reward.

Ganesh Patekar wrote:What happened when you compiled?  Did It compile or run successfully ?

Yes. Only It compiled with all constructors as it initialized with final variable.

I just confirm here. Thanks

Hi Mr. Deskmukh,

A blank final instance variable must be definitely assigned at the end of every constructor of the class in which it is declared, or a compile-time error occurs (§8.8,§16.9).

Is this rule to assign in all constructors of a class, lets consider in case for e.g. 3 constructors defined?

Thanks.

Campbell Ritchie wrote:Maybe it wasn'/quote]

Yes. Its true. It is also used for signed integer number notations like short, int, and long.

Encryption and decryption also applied it.

Noorul Hameed wrote:
 byte temp = 2290;
Yeah, typo error, it can be byte temp=22 only

Hi Mr. Deskmukh


In Switch statement, the expression implicitly required to cast. This also applies to the constant expressions in the case statements that follows the switch:
 byte temp = 2290;        switch (temp) {            case 80:                System.out.println("80");            case 127+1:                System.out.println("80");   // won't compile!            case 90 :  System.out.println("90");   default :  System.out.println("default");        }
Error occurred in the line "case 127+1"
error: incompatible types: possible lossy conversion from int to byte
Note: The other types are float, long and double are not valid as described in Java Specification.


My question is about, "Does it mean the switch expression and case expression must be similiar type? "

Thank you

Hi Mr. Hanumant Deshmukh ,

Note: ZonedDateTime not included for OCA Exam. I just mention to compare with LocalDateTime.

I found there is a difference in working with ZonedDateTime and LocalDateTime.

LocalDateTime doesn't support DateTimeFormatter.ISO_OFFSET_DATE_TIME, but ZonedLocalDateTime does.

Here is the code:
public class NewClass {        public static void main(String[] args) {        ZonedDateTime date = ZonedDateTime.now();           DateTimeFormatter f = DateTimeFormatter.ISO_OFFSET_DATE_TIME;        String text1 = date.format(f);        System.out.println(text1   );                  LocalDateTime parsedDate = date.toLocalDateTime();        String text2  =parsedDate.format(f);         System.out.println(text1 + "\n " +text2);        } }
Output is produced as follows:
2018-08-03T16:11:08.103+08:00 Exception in thread "main" java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: OffsetSeconds at java.time.LocalDate.get0(LocalDate.java:680)

What does it mean the 'OffsetSeconds' in error section?

Thank you

Dear Mr.Hanumant Deshmukh,

In another question, I also want to know the difference in CharSequence and char[] in null reference in StringBuilder. For this task, my program is written as follows.
class TestNull {  public static void main(String[] args)  { StringBuilder strb = new StringBuilder (); System.out.println( (null == new char[]{'n','u','l','l'}) ); strb.append(null); System.out.println(strb);  } } /* Compile-time error: TestNull.java:7: error: reference to append is ambiguous strb.append(null);    ^  both method append(CharSequence) in StringBuilder and method append(char[]) in StringBuilder match 1 error */
During compilation, it raised compile-time error:
What happened when it is being converted to string from null?

Thank you