Introducing Spring Framework

Chapter 1 ■ Your First Spring Application
}
url "http://repo.spring.io/libs-snapshot"
url 'http://repo.spring.io/milestone'
url 'http://repo.spring.io/libs-release'
}
Listing 1-5 shows that instead of adding the Spring Framework dependency, now you are using a
spring-boot-starter that will actually help to wire up everything to run this application as a web application.
Listing 1-6 shows your main class, the HelloWorldController; this class introduces new annotations that
will help the Spring container know what to do and create the necessary collaboration classes and run it as a web
application.
Listing 1-6. HelloWorldController.java
package com.apress.isf.spring;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@Controller
@EnableAutoConfiguration
public class HelloWorldController {
@RequestMapping("/")
@ResponseBody
String getMessage() {
return "Hello World!";
}
}
public static void main(String[] args) throws Exception {
SpringApplication.run(HelloWorldController.class, args);
}
The @Controller annotation will mark your class as a web controller that has a @RequestMapping and a
@ResponseBody. All this means is that when your web application is running, it will accept requests from the
http://localhost:8080/ URL and you should get some response back, such as the famous “Hello World” message.
Running the Spring Boot Application
Run the HelloWorldClass with the following command:
gradle - run -DmainClass=com.apress.isf.spring.HelloWorldController
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