Blog 2

Rest API

noreply@blogger.com (jayakar) — Tue, 13 Sep 2022 13:19:00 +0000

Rest (Representational State Transfer) is a standard set of rules to be followed by developer to develop API.

Six conditions that need to be met to become an Rest API

Cacheable - never having to generate same response twice

Statelessness - Not storing any information about HTTP Requests. Treating each request as new.

Client Server - Client and server must evolve separately. No dependency between each other

Uniform Interface - It simplifies and decouples the architecture, which enables each part to evlove independently

Layered System - Each layer doesn't know anything about any layer other than that of immediate layer

Code on Demand - Server may also contains code , i.e.., java applet, client script

HTTP Methods

GET: Retrieves one or more resources .
POST: Create a resource
PUT: Create new resource or Update an existing resource .It is idempotent. Do it as many times as you like, and the result is the same
DELETE: Delete an existing resource
PATCH: Update part of the resource

REST is an architectural style not protocol.

REST is Language and Platform independent.

REST can use SOAP web services because it is a concept and can use any protocol like HTTP, SOAP.

REST uses URI to expose business logic

REST does not define too much standards like SOAP.

REST requires less bandwidth and resource

RESTful web services inherits security measures from the underlying transport.

REST permits different data format such as Plain text, HTML, XML, JSON etc.

Priyanka Jain photos

noreply@blogger.com (jayakar) — Mon, 01 Feb 2021 21:50:00 +0000

Asin

noreply@blogger.com (jayakar) — Wed, 30 Dec 2020 02:34:00 +0000

AGT BUSINESS PARK COIMBATORE

noreply@blogger.com (jayakar) — Fri, 18 Dec 2020 06:00:00 +0000

Static Block vs Constructor

noreply@blogger.com (jayakar) — Wed, 18 May 2016 22:05:00 +0000

Static Block can be called once on class instantiation whereas constructor get called on every new
object instantiation.

public class Sample {
static{ //Static block can be called once
System.out.println("Static block is called");
}
Sample(){//Constructor called at any number of times
System.out.println("Constructor is called");
}
void method(){
System.out.println("Method is called");
}
static void display() {
System.out.println("Static method is called");
}
public static void main(String args[]){
Sample s=new Sample();
Sample s2=new Sample();
s.method();
System.out.println("Main method called");
display();
}
}

Output

Static block is called

Constructor is called

Method is called

Main method called

Static method is called