When not to use single-page applications?
While SPA does have its advantages, there are certain cases when it is not suitable to use it:

SEO: It is difficult and tricky to optimize SPA for SEO since its content is loaded by AJAX (Asynchronous JavaScript and XML). Hence SPAs are not suitable for cases where SEO is critical for business success.
Javascript: It requires users to enable Javascript for proper application and action loading. So it is not suitable for instances where JavaScript might be disabled on the user side.
Security: SPA is also less secure in comparison to MPA, making it unsuitable for highly sensitive applications. SPA has a cross-site scripting (XSS) and allows attackers to inject client-side scripts into the web application.
Slow: While the user experience of SPAs on runtime is fast, it is slower to download and can also be slowed down if there are memory leaks in JavaScript. It is hence not suitable for very large applications with a lot of data.

React 33-40

Please learn about @SpringBootApplication also

@SpringBootApplication
public class Application {

public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}

}

### 6. Add a main controller

java
package com.example.demo;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MainController {

@GetMapping("/")
public String index() {
return "Hello, World!";
}

}

### 7. Run the application

mvn spring-boot:run
`

### 8. Visit http://localhost:8080

You should see `Hello, World!`

@SpringBootApplication
public class App {

public static void main(String[] args) {
SpringApplication.run(App.class, args);
}

}
</code>
I have created a controller to test the basic rest call :
<code>package com.santhosh.rest.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HomeController {

@GetMapping("/")
public String home() {
return "Welcome to the world of rest";
}

}
</code>
When I hit the url <code>localhost:8080/</code> I am getting below error :
<code>Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.

Tue Apr 09 11:45:37 IST 2019
There was an unexpected error (type=Not Found, status=404).
No message available
</code>
Please help me to resolve this issue.


A:


verify if your application is running on the port 8080
check your mapping annotation
check if your application is not running multiple instances

if you are using eclipse, you can check the log console for more details about the error

Now you are end to end FullStack dev after completing this many things 😂😂

On Sunday if you guys are available I will conduct one masterclass for end to end FullStack related to the concept not for programming will clear each n every concept with real-time implementation of that particular keyword

Please let me update with your names n batch I will share Google meet link and Google forms

Do work on this part

Because if you are getting below this value u r not really enjoying the upcoming day's