Using Spring Boot without Maven

I am trying to write a simple Java program that displays Hello World as a microservice. I am using Spring Boot, but due to security reasons at my company, I am unable to use Maven. Therefore, I have no option but to download the jar files and add them to my project. I have done so, and made sure I am using the latest jar versions. When I run my program, it shows no errors BUT Tomcat server is not starting and I do not see the “Hello World” message. Below is my code:

package com.tutorials;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class HelloWorld {

    @RequestMapping("/")
    //http://localhost:port/

    String hello()
    {
        return "Hello World!";
    }

    public static void main(String[] args) throws Exception{

        SpringApplication.run(HelloWorld.class,args);
        System.out.println("done");


    }



}

and below is the output:

  .   ____          _            __ _ _
 /\ / ___'_ __ _ _(_)_ __  __ _    
( ( )___ | '_ | '_| | '_ / _` |    
 \/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |___, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.2.2.RELEASE)

2020-01-07 11:10:44.563  INFO 13224 --- [           main] com.tutorials.HelloWorld                 : Starting HelloWorld on HQTPM00184606D with PID 13224 (started by z.a in C:UsersZDesktopWorkspaceHelloWorld_Microservice)
2020-01-07 11:10:44.566  INFO 13224 --- [           main] com.tutorials.HelloWorld                 : No active profile set, falling back to default profiles: default
2020-01-07 11:10:44.938  INFO 13224 --- [           main] com.tutorials.HelloWorld                 : Started HelloWorld in 0.703 seconds (JVM running for 1.096)
done

and below is the jar files I am using:

Why Tomcat is not starting and what dependencies I am missing here? Thanks.

Answer

The dependency tree for spring-boot-starter-web 2.2.2 is:

org.springframework.boot:spring-boot-starter-web:jar:2.2.2.RELEASE:compile
+- org.springframework.boot:spring-boot-starter:jar:2.2.2.RELEASE:compile
|  +- org.springframework.boot:spring-boot:jar:2.2.2.RELEASE:compile
|  +- org.springframework.boot:spring-boot-autoconfigure:jar:2.2.2.RELEASE:compile
|  +- org.springframework.boot:spring-boot-starter-logging:jar:2.2.2.RELEASE:compile
|  |  +- ch.qos.logback:logback-classic:jar:1.2.3:compile
|  |  |  +- ch.qos.logback:logback-core:jar:1.2.3:compile
|  |  |  - org.slf4j:slf4j-api:jar:1.7.29:compile
|  |  +- org.apache.logging.log4j:log4j-to-slf4j:jar:2.12.1:compile
|  |  |  - org.apache.logging.log4j:log4j-api:jar:2.12.1:compile
|  |  - org.slf4j:jul-to-slf4j:jar:1.7.29:compile
|  +- jakarta.annotation:jakarta.annotation-api:jar:1.3.5:compile
|  +- org.springframework:spring-core:jar:5.2.2.RELEASE:compile
|  |  - org.springframework:spring-jcl:jar:5.2.2.RELEASE:compile
|  - org.yaml:snakeyaml:jar:1.25:runtime
+- org.springframework.boot:spring-boot-starter-json:jar:2.2.2.RELEASE:compile
|  +- com.fasterxml.jackson.core:jackson-databind:jar:2.10.1:compile
|  |  +- com.fasterxml.jackson.core:jackson-annotations:jar:2.10.1:compile
|  |  - com.fasterxml.jackson.core:jackson-core:jar:2.10.1:compile
|  +- com.fasterxml.jackson.datatype:jackson-datatype-jdk8:jar:2.10.1:compile
|  +- com.fasterxml.jackson.datatype:jackson-datatype-jsr310:jar:2.10.1:compile
|  - com.fasterxml.jackson.module:jackson-module-parameter-names:jar:2.10.1:compile
+- org.springframework.boot:spring-boot-starter-tomcat:jar:2.2.2.RELEASE:compile
|  +- org.apache.tomcat.embed:tomcat-embed-core:jar:9.0.29:compile
|  +- org.apache.tomcat.embed:tomcat-embed-el:jar:9.0.29:compile
|  - org.apache.tomcat.embed:tomcat-embed-websocket:jar:9.0.29:compile
+- org.springframework.boot:spring-boot-starter-validation:jar:2.2.2.RELEASE:compile
|  +- jakarta.validation:jakarta.validation-api:jar:2.0.1:compile
|  - org.hibernate.validator:hibernate-validator:jar:6.0.18.Final:compile
|     +- org.jboss.logging:jboss-logging:jar:3.4.1.Final:compile
|     - com.fasterxml:classmate:jar:1.5.1:compile
+- org.springframework:spring-web:jar:5.2.2.RELEASE:compile
|  - org.springframework:spring-beans:jar:5.2.2.RELEASE:compile
- org.springframework:spring-webmvc:jar:5.2.2.RELEASE:compile
   +- org.springframework:spring-aop:jar:5.2.2.RELEASE:compile
   +- org.springframework:spring-context:jar:5.2.2.RELEASE:compile
   - org.springframework:spring-expression:jar:5.2.2.RELEASE:compile

But as mentioned in the comments you should try to make the usage of build tools (Maven/Gradle) and a company-wide repository manager (Nexus/Artifactory) possible.