Spring Boot Hello World Example with Maven

Spring Boot is developed as a subproject of spring framework in order to create a stand-alone application with minimum possible configuration. In this Spring Boot Hello World Example, we will build a simple hello world example using Spring boot with maven.

Spring Boot Hello World Example

Step 1: Preparation for Spring Boot application

As a first step, we need to validate whether Java and Maven are installed. Open command prompt and type “java -version” to check the Java version

E:\Jackson\SpringBootTutorial>java -version
java version "1.7.0_80"
Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) Client VM (build 24.80-b11, mixed mode, sharing)

“mvn -v” for checking the maven version.

E:\Jackson\SpringBootTutorial>mvn -v
Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-10T22:11:47+05:30)
Maven home: E:\Jackson\apache-maven-3.3.9
Java version: 1.8.0_121, vendor: Oracle Corporation
Java home: C:\Program Files (x86)\Java\jdk1.8.0_121\jre
Default locale: en_IN, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "x86", family: "dos"

Step 2: Create POM file and add dependencies

Create a project Folder “SpringBootTutorial” for placing the required files. Place pom.xml in the root folder itself. Spring Boot provides a number of “Starter POMs”, in our application we have used spring-boot-starter-parent in the parent section of the POM. The spring-boot-starter-parent is a special starter that provides useful Maven defaults. spring-boot-starter-parent has no dependencies by itself.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0	http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>

   <groupId>com.javainterviewpoint</groupId>
   <artifactId>SpringBootTutorial</artifactId>
   <version>0.0.1-SNAPSHOT</version>

   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>1.5.1.RELEASE</version>
   </parent>
 </project>

Now when you run mvn dependency:tree you will not see any other jars other than our SpringBootTutorial SNAPSHOT jar.

E:\Jackson\SpringBootTutorial>mvn dependency:tree
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building SpringBootTutorial 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-dependency-plugin:2.10:tree (default-cli) @ SpringBootTutorial ---
[INFO] com.javainterviewpoint:SpringBootTutorial:jar:0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.524 s
[INFO] Finished at: 2017-02-19T15:32:47+05:30
[INFO] Final Memory: 14M/33M
[INFO] ------------------------------------------------------------------------

Since we are developing a web application, we also need to add spring-boot-starter-web dependency.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0	http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>

   <groupId>com.javainterviewpoint</groupId>
   <artifactId>SpringBootTutorial</artifactId>
   <version>0.0.1-SNAPSHOT</version>

   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>1.5.1.RELEASE</version>
   </parent>
   
   <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
   </dependencies>
 </project>

Now when you run mvn dependency:tree you can see there will number of additional dependencies added including Tomcat, Jackson, Spring boot etc.

E:\Jackson\SpringBootTutorial>mvn dependency:tree
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building SpringBootTutorial 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-dependency-plugin:2.10:tree (default-cli) @ SpringBootTutorial ---
[INFO] com.javainterviewpoint:SpringBootTutorial:jar:0.0.1-SNAPSHOT
[INFO] \- org.springframework.boot:spring-boot-starter-web:jar:1.5.1.RELEASE:compile
[INFO]    +- org.springframework.boot:spring-boot-starter:jar:1.5.1.RELEASE:compile
[INFO]    |  +- org.springframework.boot:spring-boot:jar:1.5.1.RELEASE:compile
[INFO]    |  +- org.springframework.boot:spring-boot-autoconfigure:jar:1.5.1.RELEASE:compile
[INFO]    |  +- org.springframework.boot:spring-boot-starter-logging:jar:1.5.1.RELEASE:compile
[INFO]    |  |  +- ch.qos.logback:logback-classic:jar:1.1.9:compile
[INFO]    |  |  |  +- ch.qos.logback:logback-core:jar:1.1.9:compile
[INFO]    |  |  |  \- org.slf4j:slf4j-api:jar:1.7.22:compile
[INFO]    |  |  +- org.slf4j:jcl-over-slf4j:jar:1.7.22:compile
[INFO]    |  |  +- org.slf4j:jul-to-slf4j:jar:1.7.22:compile
[INFO]    |  |  \- org.slf4j:log4j-over-slf4j:jar:1.7.22:compile
[INFO]    |  +- org.springframework:spring-core:jar:4.3.6.RELEASE:compile
[INFO]    |  \- org.yaml:snakeyaml:jar:1.17:runtime
[INFO]    +- org.springframework.boot:spring-boot-starter-tomcat:jar:1.5.1.RELEASE:compile
[INFO]    |  +- org.apache.tomcat.embed:tomcat-embed-core:jar:8.5.11:compile
[INFO]    |  +- org.apache.tomcat.embed:tomcat-embed-el:jar:8.5.11:compile
[INFO]    |  \- org.apache.tomcat.embed:tomcat-embed-websocket:jar:8.5.11:compile
[INFO]    +- org.hibernate:hibernate-validator:jar:5.3.4.Final:compile
[INFO]    |  +- javax.validation:validation-api:jar:1.1.0.Final:compile
[INFO]    |  +- org.jboss.logging:jboss-logging:jar:3.3.0.Final:compile
[INFO]    |  \- com.fasterxml:classmate:jar:1.3.3:compile
[INFO]    +- com.fasterxml.jackson.core:jackson-databind:jar:2.8.6:compile
[INFO]    |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.8.0:compile
[INFO]    |  \- com.fasterxml.jackson.core:jackson-core:jar:2.8.6:compile
[INFO]    +- org.springframework:spring-web:jar:4.3.6.RELEASE:compile
[INFO]    |  +- org.springframework:spring-aop:jar:4.3.6.RELEASE:compile
[INFO]    |  +- org.springframework:spring-beans:jar:4.3.6.RELEASE:compile
[INFO]    |  \- org.springframework:spring-context:jar:4.3.6.RELEASE:compile
[INFO]    \- org.springframework:spring-webmvc:jar:4.3.6.RELEASE:compile
[INFO]       \- org.springframework:spring-expression:jar:4.3.6.RELEASE:compile
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.724 s
[INFO] Finished at: 2017-02-19T15:36:40+05:30
[INFO] Final Memory: 15M/38M
[INFO] ------------------------------------------------------------------------

Run “mvn package” command to create a package, now the folder structure will be

|-- pom.xml
|-- target
    |-- maven-archiver
    |   |-- pom.properties
    |-- SpringBootTutorial-0.0.1-SNAPSHOT.jar

Step 3: Creation of the Java File

We will be having a single java file for our HelloWorld example. Maven by default will be compiling all the java files which are under src/main/java, hence we need to create our HelloWorld.java under src/main/java folder

package com.javainterviewpoint;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class HelloWorld {

    @RequestMapping("/")
    String hello() {
        return "Hello World! JavaInterviewPoint";
    }

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

We have added the below annotations in HelloWorld class

@RestController – This annotation is a stereotype annotation, this annotation tells spring to render the result back to the caller.
@RequestMapping – This annotation will any HTTP request with the path. In our application “/” should be mapped to the hello() method
@EnableAutoConfiguration – This annotation tells the Spring Boot to configure the application based on the dependencies added. Since spring-boot-starter-web has added Tomcat and Spring MVC, auto-configuration will setup a web based application.

Our main() method is the triggering point of our java application, it in-turn calls Spring Boot’s SpringApplication class run() method which bootstraps our HelloWorld application and starts the tomcat server. We need to pass our HelloWorld.class as an argument to our run() method.

Again run “mvn package” command after placing the java file

|-- pom.xml
|-- src
|   |-- main
|       |-- java
|           |--HelloWorld.java
|-- target
    |-- classes
    |   |-- HelloWorld.class
    |-- generated-sources
    |   |-- annotations
    |-- maven-archiver
    |   |-- pom.properties
    |-- maven-status
    |   |-- maven-compiler-plugin
    |       |-- compile
    |           |-- default-compile
    |               |-- createdFiles.lst
    |               |-- inputFiles.lst
    |-- SpringBootTutorial-0.0.1-SNAPSHOT.jar

Step 4: Execution

We will be executing our Spring Boot Hello World example in two different ways.

Using spring-boot: run
Creating an executable jar and running the jar

1. Running using spring-boot:run

In the command prompt from the root directory of the project start the application using the command “mvn spring-boot:run”

E:\Jackson\SpringBootTutorial>mvn spring-boot:run
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building SpringBootTutorial 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> spring-boot-maven-plugin:1.5.1.RELEASE:run (default-cli) > test-compile @ SpringBootTutorial >>>
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ SpringBootTutorial ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Jackson\SpringBootTutorial\src\main\resources
[INFO] skip non existing resourceDirectory E:\Jackson\SpringBootTutorial\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ SpringBootTutorial ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ SpringBootTutorial ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory E:\Jackson\SpringBootTutorial\src\test\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ SpringBootTutorial ---
[INFO] No sources to compile
[INFO]
[INFO] <<< spring-boot-maven-plugin:1.5.1.RELEASE:run (default-cli) < test-compile @ SpringBootTutorial <<<
[INFO]
[INFO] --- spring-boot-maven-plugin:1.5.1.RELEASE:run (default-cli) @ SpringBootTutorial ---

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.1.RELEASE)

2017-02-19 15:48:02.057  INFO 1848 --- [           main] HelloWorld                               : Starting HelloWorld on user-PC with PID 1848 (E:\Jackson\Spr
ingBootTutorial\target\classes started by user in E:\Jackson\SpringBootTutorial)
2017-02-19 15:48:02.060  INFO 1848 --- [           main] HelloWorld                               : No active profile set, falling back to default profiles: def
ault
2017-02-19 15:48:02.095  INFO 1848 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.Annotat
[email protected]: startup date [Sun Feb 19 15:48:02 IST 2017]; root of context hierarchy
2017-02-19 15:48:02.942  INFO 1848 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.boot.autoconfigure.validation.Vali
dationAutoConfiguration' of type [class org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration] is not eligible for getting processed by
all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-02-19 15:48:03.026  INFO 1848 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'validator' of type [class org.springframework.validati
on.beanvalidation.LocalValidatorFactoryBean] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-02-19 15:48:03.416  INFO 1848 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-02-19 15:48:03.427  INFO 1848 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2017-02-19 15:48:03.428  INFO 1848 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.11
2017-02-19 15:48:03.504  INFO 1848 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-02-19 15:48:03.505  INFO 1848 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1411
 ms
2017-02-19 15:48:03.650  INFO 1848 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-02-19 15:48:03.654  INFO 1848 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-02-19 15:48:03.655  INFO 1848 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-02-19 15:48:03.655  INFO 1848 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-02-19 15:48:03.656  INFO 1848 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-02-19 15:48:04.088  INFO 1848 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.cont
[email protected]3: startup date [Sun Feb 19 15:48:02 IST 2017]; root of context hierarchy
2017-02-19 15:48:04.158  INFO 1848 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto java.lang.String HelloWorld.home()
2017-02-19 15:48:04.163  INFO 1848 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.spr
ingframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.serv
let.http.HttpServletResponse)
2017-02-19 15:48:04.164  INFO 1848 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.Res
ponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServ
letRequest)
2017-02-19 15:48:04.197  INFO 1848 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class or
g.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-19 15:48:04.198  INFO 1848 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.spring
framework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-19 15:48:04.242  INFO 1848 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [clas
s org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-19 15:48:04.404  INFO 1848 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-02-19 15:48:04.466  INFO 1848 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-02-19 15:48:04.472  INFO 1848 --- [           main] HelloWorld                               : Started HelloWorld in 2.776 seconds (JVM running for 5.822)
2017-02-19 15:48:11.749  INFO 1848 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-02-19 15:48:11.749  INFO 1848 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started

2017-02-19 15:48:11.766  INFO 1848 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization complet
ed in 16 ms

Output :

Now you will have everything started, hit on the URL “http://localhost:8080”

2. Creating an executable jar and running the jar

Let’s create an executable jar file, in order to create an executable jar we need to add the spring-boot-maven-plugin to our pom.xml. Now our modified pom file looks like below

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0	http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>

   <groupId>com.javainterviewpoint</groupId>
   <artifactId>SpringBootTutorial</artifactId>
   <version>0.0.1-SNAPSHOT</version>

   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>1.5.1.RELEASE</version>
   </parent>
   
   <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
   </dependencies>
   <build>
     <plugins>
       <plugin>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-maven-plugin</artifactId>
       </plugin>
     </plugins>
   </build>
 </project>

Now run the package command again (mvn package)

|-- pom.xml
|-- src
|   |-- main
|       |-- java
|           |--HelloWorld.java
|-- target
    |-- classes
    |   |-- HelloWorld.class
    |-- generated-sources
    |   |-- annotations
    |-- maven-archiver
    |   |-- pom.properties
    |-- maven-status
    |   |-- maven-compiler-plugin
    |       |-- compile
    |           |-- default-compile
    |               |-- createdFiles.lst
    |               |-- inputFiles.lst
    |-- SpringBootTutorial-0.0.1-SNAPSHOT.jar
    |-- SpringBootTutorial-0.0.1-SNAPSHOT.jar.original

Now you will see a .original file created along with our .jar file. In order to run the jar which we built, use “java -jar” command

C:\Jackson\SpringBootTutorial>java -jar target/SpringBootTutorial-0.0.1-SNAPSHOT.jar

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.1.RELEASE)

2017-02-21 10:28:38.799  INFO 7892 --- [           main] HelloWorld                               : Starting HelloWorld on DA56CZ8VD02 with PID 7892 (C:\Jackson\SpringBootTutorial\target\SpringBootTutorial-0.0.1-SNAPSHOT.jar started by xbbl47m in C:\Jackson\SpringBootTutorial)
2017-02-21 10:28:38.805  INFO 7892 --- [           main] HelloWorld                               : No active profile set, falling back to default profiles: default
2017-02-21 10:28:38.876  INFO 7892 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot[email protected]920d014: startup date [Tue Feb 21 10:28:38 IST 2017]; root of context hierarchy
2017-02-21 10:28:39.955  INFO 7892 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration' of type [class org.springframework.boot.autoconfigure.validation.ValidationAutoConfiguration] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-02-21 10:28:40.118  INFO 7892 --- [           main] trationDelegate$BeanPostProcessorChecker : Bean 'validator' of type [class org.springframework.validation.beanvalidation.LocalValidatorFactoryBean] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2017-02-21 10:28:40.596  INFO 7892 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2017-02-21 10:28:40.611  INFO 7892 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2017-02-21 10:28:40.613  INFO 7892 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.11
2017-02-21 10:28:40.727  INFO 7892 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2017-02-21 10:28:40.727  INFO 7892 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1853 ms
2017-02-21 10:28:40.904  INFO 7892 --- [ost-startStop-1] o.s.b.w.servlet.ServletRegistrationBean  : Mapping servlet: 'dispatcherServlet' to [/]
2017-02-21 10:28:40.910  INFO 7892 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'characterEncodingFilter' to: [/*]
2017-02-21 10:28:40.911  INFO 7892 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
2017-02-21 10:28:40.911  INFO 7892 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'httpPutFormContentFilter' to: [/*]
2017-02-21 10:28:40.911  INFO 7892 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2017-02-21 10:28:41.260  INFO 7892 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot[email protected]920d014: startup date [Tue Feb 21 10:28:38 IST 2017]; root of context hierarchy
2017-02-21 10:28:41.379  INFO 7892 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/]}" onto java.lang.String HelloWorld.hello()
2017-02-21 10:28:41.384  INFO 7892 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2017-02-21 10:28:41.385  INFO 7892 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2017-02-21 10:28:41.425  INFO 7892 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-21 10:28:41.425  INFO 7892 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-21 10:28:41.482  INFO 7892 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2017-02-21 10:28:41.740  INFO 7892 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-02-21 10:28:41.832  INFO 7892 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2017-02-21 10:28:41.840  INFO 7892 --- [           main] HelloWorld                               : Started HelloWorld in 3.658 seconds (JVM running for 4.228)
2017-02-21 10:28:58.337  INFO 7892 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring FrameworkServlet 'dispatcherServlet'
2017-02-21 10:28:58.337  INFO 7892 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization started
2017-02-21 10:28:58.358  INFO 7892 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : FrameworkServlet 'dispatcherServlet': initialization completed in 21 ms

hit on the URL “http://localhost:8080” you will get the same output.

Spring Boot Hello World Example with Maven