How to deploy a simple Spring Boot (with Gradle build system) to Apache Tomcat (real server, not embed server)?

Question

I follow this tutorial: http://spring.io/guides/gs/rest-service/
This is my project structure:

build.gradle

buildscript{
    repositories{
        mavenCentral()
    }
    dependencies{
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.3.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar{
    baseName = 'gs-rest-service'
    version = '0.1.0'
}

repositories{
    mavenCentral()
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies{
    compile("org.springframework.boot:spring-boot-starter-web") 
    testCompile("junit:junit")
}
task wrapper(type: Wrapper){
    gradleVersion = '2.3'
}

Application.java

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

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

}

Greeting.java

package hello;

public class Greeting {

    private final long id;
    private final String content;

    public Greeting(long id, String content) {
        super();
        this.id = id;
        this.content = content;
    }

    public long getId() {
        return id;
    }

    public String getContent() {
        return content;
    }

}

GreetingControler.java

package hello;

import java.util.concurrent.atomic.AtomicLong;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class GreetingController {

    private static final String template = "Hello, %s";
    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value = "name", defaultValue = "World") String name) {
        return new Greeting(counter.incrementAndGet(), String.format(template, name));
    }

}

I know how to run Spring Boot application by gradle bootRun command (run on Apache Tomcat embed server). But I don't know how to run above Spring Boot application on real Apache Tomcat (Please help me at this point!)

Answer 1

Follow comments's manish, I create source base from http://start.spring.io/

Then I import to Eclipse for Java EE (with Spring Tools Suite, Gradle plugin), this is project folder structure:

Greeting.java

package hello;

public class Greeting {

    private final long id;
    private final String content;

    public Greeting(long id, String content) {
        this.id = id;
        this.content = content;
    }

    public long getId() {
        return id;
    }

    public String getContent() {
        return content;
    }
}

GreetingController

package hello;

import java.util.concurrent.atomic.AtomicLong;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class GreetingController {

    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value="name", defaultValue="World") String name) {
        return new Greeting(counter.incrementAndGet(),
                            String.format(template, name));
    }
}

I modified file GsRestServiceApplication.java

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class GsRestServiceApplication {

    public static void main(String[] args) {
        SpringApplication.run(GreetingController.class, args); // <-- modify this line.
    }
}

I don't change file GsRestServiceApplication.java

package hello;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.context.web.SpringBootServletInitializer;

public class ServletInitializer extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(GsRestServiceApplication.class);
    }

}

I can run web app in real Tomcat server:

Then I use browser or Postman to view result:

http://localhost:8080/gs-rest-service/greeting?name=Vy

Answer 2

You're using Gradle. Try to add this in your build.gradle file.

dependencies {
   providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
}

Don't forget to remove:

compile("org.springframework.boot:spring-boot-starter-web")