How to run Spring Boot quick start code

Question

I am new to Spring and Spring Boot, and I am trying it out. I am having trouble running the code sample from https://projects.spring.io/spring-boot/.

package hello;

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;

@Controller
@EnableAutoConfiguration
public class SampleController {

    @RequestMapping("/")
    @ResponseBody
    String home() {
        return "Hello World!";
    }

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

I issued mvn install and everything appears to be fine. But then I issued java -cp target/myArtifId-1.0-SNAPSHOT.jar hello.SampleController and ClassNotFoundException is thrown.

How do I run this code sample?

if you are newbie to spring-boot, please refer this approach to kick start. http://stackoverflow.com/questions/39245732/java-lang-noclassdeffounderror-org-springframework-core-env-configurableenviron/39246493#39246493 — Praveen Kumar K S, May 01 '17 at 10:22

score 2 · Answer 1 · answered May 01 '17 at 09:53

2

As per spring boot documentation, you should be able to run your application with this command:

java -jar target/myArtifId-1.0-SNAPSHOT.jar

Spring Boot produces an executable jar, no need to specify a java class with a main method. That's also the reason why you can not include another class with a main method.

answered May 01 '17 at 09:53

François Maturel

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For the OP's benefit: This is really about jars, but you can look at MANIFEST.MF and see what `Main-Class` is. In this case, it's `org.springframework.boot.loader.JarLauncher`. So the above command is equivalent to: `java -cp target/myArtifId-1.0-SNAPSHOT.jar org.springframework.boot.loader.JarLauncher` – flow2k May 04 '17 at 07:19
And after the Tomcat server starts, you can either 1) issue `curl localhost:8080`, or 2) point your browser to `localhost:8080`. Or if connecting over the network, you can of course point browser to `xx.xx.xx.xx:8080`. You should then see "Hello World!". – flow2k May 04 '17 at 07:28

score 1 · Answer 2 · answered May 01 '17 at 10:17

1

I prefer to use run goal of Spring Boot Maven Plugin to compile and run it in a single command:

mvn spring-boot:run

answered May 01 '17 at 10:17

Pau

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How to run Spring Boot quick start code

2 Answers2