Spring Boot Hello World using STS

Firstly you need to download STS from below link:

Download STS (Spring Tool Suite) from Here

Then simply download and install on your machine then open it like below:

After that you need to select or create a workspace where your project will be stored.

After this you need to select File menu and create a Spring Starter project like below:

After this give some information about your project like project name, artifact-id, group-by, type, packaging, java version etc. like below:

After giving all details you have to select dependency Spring-Web like below:

When you click on Finish make sure you have to connect with a stable internet connection because maven download dependency from remote repository to local repository.

Now your project is configured so it will create a default project structure and code like below:

Now you need to open FirstExampleApplication.java file and look like below code:

package com.deepsingh44.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class FirstExampleApplication {

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

}

Create a new class inside the same package HelloController.java and write below code:

HelloController.java

package com.deepsingh44.demo;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

	@GetMapping("/")
	public String helloWorld() {
		return "Hello First Program";
	}

}

After this right click on your project and select Run As-> Spring Boot App like below:

If your application show error that is port 8080 was already in use like below:

So you need to change the port number in application.properties file like below:

server.port=8888

Then run your application again and it will run successfully like below:

Now you have to open any browser and write like below:

Finally you can see your result on your browser Thanks.