
- Spring Boot - Home
- Spring Boot - Introduction
- Spring Boot - Quick Start
- Spring Boot - Bootstrapping
- Spring Tool Suite
- Spring Boot - Tomcat Deployment
- Spring Boot - Build Systems
- Spring Boot - Code Structure
- Spring Beans & Dependency Injection
- Spring Boot - Runners
- Spring Boot - Starters
- Spring Boot - Application Properties
- Spring Boot - Configuration
- Spring Boot - Annotations
- Spring Boot - Logging
- Building RESTful Web Services
- Spring Boot - Exception Handling
- Spring Boot - Interceptor
- Spring Boot - Servlet Filter
- Spring Boot - Tomcat Port Number
- Spring Boot - Rest Template
- Spring Boot - File Handling
- Spring Boot - Service Components
- Spring Boot - Thymeleaf
- Consuming RESTful Web Services
- Spring Boot - CORS Support
- Spring Boot - Internationalization
- Spring Boot - Scheduling
- Spring Boot - Enabling HTTPS
- Spring Boot - Eureka Server
- Service Registration with Eureka
- Gateway Proxy Server and Routing
- Spring Cloud Configuration Server
- Spring Cloud Configuration Client
- Spring Boot - Actuator
- Spring Boot - Admin Server
- Spring Boot - Admin Client
- Spring Boot - Enabling Swagger2
- Spring Boot - Using SpringDoc OpenAPI
- Spring Boot - Creating Docker Image
- Tracing Micro Service Logs
- Spring Boot - Flyway Database
- Spring Boot - Sending Email
- Spring Boot - Hystrix
- Spring Boot - Web Socket
- Spring Boot - Batch Service
- Spring Boot - Apache Kafka
- Spring Boot - Twilio
- Spring Boot - Unit Test Cases
- Rest Controller Unit Test
- Spring Boot - Database Handling
- Securing Web Applications
- Spring Boot - OAuth2 with JWT
- Spring Boot - Google Cloud Platform
- Spring Boot - Google OAuth2 Sign-In
Spring Boot - Bootstrapping
This chapter will explain you how to perform bootstrapping on a Spring Boot application.
Spring Initializer
One of the ways to Bootstrapping a Spring Boot application is by using Spring Initializer. To do this, you will have to visit the Spring Initializer web page www.start.spring.io and choose your Build, Spring Boot Version and platform. Also, you need to provide a Group, Artifact and required dependencies to run the application.
Observe the following screenshot that shows an example where we added the spring-boot-starter-web dependency to write REST Endpoints.

Once you provided the Group, Artifact, Dependencies, Build Project, Platform and Version, click Generate Project button. The zip file will download and the files will be extracted.
This section explains you the examples by using both Maven and Gradle.
Maven
After you download the project, unzip the file. Now, your pom.xml file looks as shown 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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>3.3.3</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.tutorialspoint</groupId> <artifactId>demo</artifactId> <version>0.0.1-SNAPSHOT</version> <name>demo</name> <description>Demo project for Spring Boot</description> <url/> <licenses> <license/> </licenses> <developers> <developer/> </developers> <scm> <connection/> <developerConnection/> <tag/> <url/> </scm> <properties> <java.version>21</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
Gradle
In case of Gradle, you can check the build.gradle as following:
build.gradle
buildscript { ext { springBootVersion = '3.3.3' } repositories { mavenCentral() } dependencies { classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}") } } apply plugin: 'java' apply plugin: 'eclipse' apply plugin: 'org.springframework.boot' group = 'com.tutorialspoint' version = '0.0.1-SNAPSHOT' sourceCompatibility = 21 repositories { mavenCentral() } dependencies { compile('org.springframework.boot:spring-boot-starter-web') testCompile('org.springframework.boot:spring-boot-starter-test') }
Class Path Dependencies
Spring Boot provides a number of Starters to add the jars in our class path. For example, for writing a Rest Endpoint, we need to add the spring-boot-starter-web dependency in our class path. Observe the codes shown below for a better understanding −
Maven dependency
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies>
Gradle dependencies
dependencies { compile('org.springframework.boot:spring-boot-starter-web') }
Main Method
The main method should be writing the Spring Boot Application class. This class should be annotated with @SpringBootApplication. This is the entry point of the spring boot application to start. You can find the main class file under src/java/main directories with the default package.
In this example, the main class file is located at the src/java/main directories with the default package com.tutorialspoint.demo. Observe the code shown here for a better understanding −
package com.tutorialspoint.demo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class DemoApplication { public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); } }
Write a Rest Endpoint
To write a simple Hello World Rest Endpoint in the Spring Boot Application main class file itself, follow the steps shown below −
Firstly, add the @RestController annotation at the top of the class.
Now, write a Request URI method with @GetMapping annotation.
Then, the Request URI method should return the Hello World string.
Now, your main Spring Boot Application class file will look like as shown in the code given below −
package com.tutorialspoint.demo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController @SpringBootApplication public class DemoApplication { public static void main(String[] args) { SpringApplication.run(DemoApplication.class, args); } @GetMapping(value = "/") public String hello() { return "Hello World"; } }
Create an Executable JAR
Let us create an executable JAR file to run the Spring Boot application by using Maven commands in the command prompt as shown below −
Use the Maven command mvn clean install as shown below −
E:\dev\demo>mvn clean install
You'll see the result similar to as below:
[INFO] Scanning for projects... [INFO] [INFO] [1m----------------------< [0;36mcom.tutorialspoint:demo[0;1m >-----------------------[m [INFO] [1mBuilding demo 0.0.1-SNAPSHOT[m [INFO] from pom.xml [INFO] [1m--------------------------------[ jar ]---------------------------------[m [INFO] Downloading from central: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-install-plugin/3.1.3/maven-install-plugin-3.1.3.pom .... [INFO] [INFO] [1m--- [0;32mclean:3.3.2:clean[m [1m(default-clean)[m @ [36mdemo[0;1m ---[m [INFO] Deleting E:\Dev\demo\target [INFO] [INFO] [1m--- [0;32mresources:3.3.1:resources[m [1m(default-resources)[m @ [36mdemo[0;1m ---[m [INFO] Copying 1 resource from src\main\resources to target\classes [INFO] Copying 0 resource from src\main\resources to target\classes [INFO] ... [INFO] [INFO] [1m--- [0;32msurefire:3.2.5:test[m [1m(default-test)[m @ [36mdemo[0;1m ---[m [INFO] Using auto detected provider org.apache.maven.surefire.junitplatform.JUnitPlatformProvider [INFO] Downloading from central: https://repo.maven.apache.org/maven2/org/junit/platform/junit-platform-launcher/1.10.3/junit-platform-launcher-1.10.3.pom [INFO] Downloaded from central: https://repo.maven.apache.org/maven2/org/junit/platform/junit-platform-launcher/1.10.3/junit-platform-launcher-1.10.3.pom (3.0 kB at 13 kB/s) [INFO] [INFO] ------------------------------------------------------- [INFO] T E S T S [INFO] ------------------------------------------------------- [INFO] Running com.tutorialspoint.demo.[1mDemoApplicationTests[m 17:35:15.626 [main] INFO org.springframework.test.context.support.AnnotationConfigContextLoaderUtils -- Could not detect default configuration classes for test class [com.tutorialspoint.demo.DemoApplicationTests]: DemoApplicationTests does not declare any static, non-private, non-final, nested classes annotated with @Configuration. 17:35:15.802 [main] INFO org.springframework.boot.test.context.SpringBootTestContextBootstrapper -- Found @SpringBootConfiguration com.tutorialspoint.demo.DemoApplication for test class com.tutorialspoint.demo.DemoApplicationTests . ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v3.3.3) 2024-09-02T17:35:16.380+05:30 INFO 6204 --- [demo] [ main] c.t.demo.DemoApplicationTests : Starting DemoApplicationTests using Java 21.0.3 with PID 6204 (started by Tutorialspoint in E:\Dev\demo) 2024-09-02T17:35:16.381+05:30 INFO 6204 --- [demo] [ main] c.t.demo.DemoApplicationTests : No active profile set, falling back to 1 default profile: "default" 2024-09-02T17:35:18.173+05:30 INFO 6204 --- [demo] [ main] c.t.demo.DemoApplicationTests : Started DemoApplicationTests in 2.162 seconds (process running for 4.295) ... [INFO] Results: [INFO] [INFO] [1;32mTests run: 1, Failures: 0, Errors: 0, Skipped: 0[m [INFO] [INFO] [INFO] [1m--- [0;32mjar:3.4.2:jar[m [1m(default-jar)[m @ [36mdemo[0;1m ---[m [INFO] Building jar: E:\Dev\demo\target\demo-0.0.1-SNAPSHOT.jar [INFO] [INFO] [1m--- [0;32mspring-boot:3.3.3:repackage[m [1m(repackage)[m @ [36mdemo[0;1m ---[m [INFO] Replacing main artifact E:\Dev\demo\target\demo-0.0.1-SNAPSHOT.jar with repackaged archive, adding nested dependencies in BOOT-INF/. [INFO] The original artifact has been renamed to E:\Dev\demo\target\demo-0.0.1-SNAPSHOT.jar.original [INFO] [INFO] [1m--- [0;32minstall:3.1.3:install[m [1m(default-install)[m @ [36mdemo[0;1m ---[m .... [INFO] Downloaded from central: https://repo.maven.apache.org/maven2/org/codehaus/plexus/plexus-xml/3.0.1/plexus-xml-3.0.1.jar (94 kB at 806 kB/s) [INFO] Installing E:\Dev\demo\pom.xml to C:\Users\Tutorialspoint\.m2\repository\com\tutorialspoint\demo\0.0.1-SNAPSHOT\demo-0.0.1-SNAPSHOT.pom [INFO] Installing E:\Dev\demo\target\demo-0.0.1-SNAPSHOT.jar to C:\Users\Tutorialspoint\.m2\repository\com\tutorialspoint\demo\0.0.1-SNAPSHOT\demo-0.0.1-SNAPSHOT.jar [INFO] [1m------------------------------------------------------------------------[m [INFO] [1;32mBUILD SUCCESS[m [INFO] [1m------------------------------------------------------------------------[m [INFO] Total time: 18.938 s [INFO] Finished at: 2024-09-02T17:35:25+05:30 [INFO] [1m------------------------------------------------------------------------[m
Similarly for Gradle, you can run the following command to build the jar.
gradle clean build
Run Hello World with Java
Once you have created an executable JAR file, you can find it under the target directory. In our case it is in E: > Dev > demo > target > demo-0.0.1-SNAPSHOT.jar.
Now, run the JAR file by using the command java jar <JARFILE>. Observe that in the above example, the JAR file is named demo-0.0.1-SNAPSHOT.jar
E:\dev\demo\target>java -jar demo-0.0.1-SNAPSHOT.jar
Once you run the jar file, you can see the output in the console window as shown below −
. ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v3.3.3) 2024-09-02T17:42:38.623+05:30 INFO 4712 --- [demo] [ main] c.tutorialspoint.demo.DemoApplication : Starting DemoApplication v0.0.1-SNAPSHOT using Java 21.0.2 with PID 4712 (E:\Dev\demo\target\demo-0.0.1-SNAPSHOT.jar started by Tutorialspoint in E:\Dev\demo\target) 2024-09-02T17:42:38.626+05:30 INFO 4712 --- [demo] [ main] c.tutorialspoint.demo.DemoApplication : No active profile set, falling back to 1 default profile: "default" 2024-09-02T17:42:40.250+05:30 INFO 4712 --- [demo] [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port 8080 (http) 2024-09-02T17:42:40.266+05:30 INFO 4712 --- [demo] [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2024-09-02T17:42:40.266+05:30 INFO 4712 --- [demo] [ main] o.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/10.1.28] 2024-09-02T17:42:40.320+05:30 INFO 4712 --- [demo] [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext 2024-09-02T17:42:40.322+05:30 INFO 4712 --- [demo] [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1574 ms 2024-09-02T17:42:40.943+05:30 INFO 4712 --- [demo] [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port 8080 (http) with context path '/' 2024-09-02T17:42:40.969+05:30 INFO 4712 --- [demo] [ main] c.tutorialspoint.demo.DemoApplication : Started DemoApplication in 3.122 seconds (process running for 3.902)
Now, look at the console, Tomcat started on port 8080 (http). Now, go to the web browser and hit the URL http://localhost:8080/ and you can see the output as shown below −
