Spring Boot - Project Structure

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a)Open "https://spring.io/tools" in Browser.

b)Click on "Spring Tool Suite for Eclipse "Windows 64 bit".

c)Get "spring-tool-suite-4-4.4.0.RELEASE-e4.13.0-win32.win32.x86_64.zip" from downloads

and unzip at C drive.

d)Find "sts-4.4.0.RELEASE" folder at C driver and open "sts-4.4.0.RELEASE" and double click

on "SpringToolSuite4" Application.

e)Provide workspace "D:\springbootpractice" .

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a)Select "File"--> "New"--> "Spring Starter Project".

b)Provide the following details.

a)Name: helloapp

b)Group : com.durgasoft

c)Artifact: helloapp

d)Description: HelloApp for Spring Boot

e)package: com.durgasoft

c)Click on "Next" button.

d)Select the required modules like "web" --"Spring Web".

e)Click on "Next".

f)Click on "Finish" button.

If we do the above steps then we will get SpringBoot project at Project Explorer part.

c)Open HelloApplication.java file which is existed at

"src\main\java\com.durgasoft.HelloApplication.java" and write sop(-).

EX: HelloApplication.java:

-----------------------------------

package com.durgasoft;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class HelloappApplication {

public static void main(String[] args) {

SpringApplication.run(HelloappApplication.class, args);

System.out.println("HelloApplication from Spring");

}

}

d)Run "HelloApplication" by clicking on "Run" button then we will get Output.

/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \

\\/ ___)| |_)| | | | | || (_| | ) ) ) )

' |____| .__|_| |_|_| |_\__, | / / / /

=========|_|==============|___/=/_/_/_/

:: Spring Boot :: (v2.1.9.RELEASE)

2019-10-07 10:43:43.483 INFO 16632 --- [ main] com.durgasoft.HelloappApplication

: Starting HelloappApplication on DESKTOP-LTICM7V with PID 16632

(D:\spring_boot_practice\sts\helloapp\target\classes started by Nagoor in

D:\spring_boot_practice\sts\helloapp)

2019-10-07 10:43:43.486 INFO 16632 --- [ main] com.durgasoft.HelloappApplication

: No active profile set, falling back to default profiles: default

2019-10-07 10:43:44.444 INFO 16632 --- [ main]

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 2222 (http)

2019-10-07 10:43:44.475 INFO 16632 --- [ main]

o.apache.catalina.core.StandardService : Starting service [Tomcat]

2019-10-07 10:43:44.475 INFO 16632 --- [ main]

org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.26]

2019-10-07 10:43:44.603 INFO 16632 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] :

Initializing Spring embedded WebApplicationContext

2019-10-07 10:43:44.603 INFO 16632 --- [ main] o.s.web.context.ContextLoader

: Root WebApplicationContext: initialization completed in 1065 ms

2019-10-07 10:43:44.796 INFO 16632 --- [ main]

o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService

'applicationTaskExecutor'

2019-10-07 10:43:44.925 INFO 16632 --- [ main]

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 2222 (http) with

context path ''

2019-10-07 10:43:44.928 INFO 16632 --- [ main] com.durgasoft.HelloappApplication

: Started HelloappApplication in 1.831 seconds (JVM running for 2.894)

HelloApplication from Spring

Note: If 8080 port is busy in our system then change server port number by using key-value

pair "server.port=2222" in application.properties which is available under

"src\main\resources\application.properties".

e)If we want to execute through Web Client then prepare controller class with handler

method.

EX: HelloController.java

---------------------------------

package com.durgasoft.controller;

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

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

@RestController

public class HelloController {

@RequestMapping("/hello")

public String sayHello() {

return "Hello User!";

}

}

f)Execute HelloApplication appliocation and open browser and use the following URL at

address bar.

http://localhost:2222/hello

• Spring Boot Initializr:

------------------------------

-->Spring Boot initializr is a web tool , it will provide option to generate Spring boot projects

directly as per the provided project details.

-->Spring Boot Initializr will give an option to download the project directly from web and

to execute through Eclipse IDE or some other.

Steps:

-------

• Create Spring Boot Project and Download project:
• Import Spring boot Application in STS:
• Create Spring Boot Project and Download project:

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a)Open "https://start.spring.io" URL at address bar in browser.

a)project: Maven Project

b)Language : JAVA

c)Spring Boot: 2.1.9

group: com.durgasoft

artifact: helloapp

Options:

Name: helloapp

Description: Helloapp for Spring Boot

Packaging : jar

JAVA: 8

Dependencies: web --> Spring Web

c)Click on "Generate" button.

If we do the above step then helloapp.zip file is generated and downloaded.

• Import Spring boot Application in STS:

------------------------------------------------------

a)Copy helloapp.zip" file to "D:\mywebapps" location from downloads.

b)Unzip "helloapp.zip" file.

d)Open "com.durgasoft.HelloappApplication.java" from src\main\java and do required

modifications.

EX: HelloappApplication.java

------------------------------

package com.durgasoft;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication

public class HelloappApplication {

public static void main(String[] args) {

SpringApplication.run(HelloappApplication.class, args);

}

}

Note: If 8080 port is busy in our system then change port number from 8080 to some other

by providing "server.port" in application.properties file which is existed in

"src\Main\resources\application.properties".

e)Execute HelloappApplication.java file by clicking on "Run" button.

Output:

/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \

\\/ ___)| |_)| | | | | || (_| | ) ) ) )

' |____| .__|_| |_|_| |_\__, | / / / /

=========|_|==============|___/=/_/_/_/

:: Spring Boot :: (v2.1.9.RELEASE)

2019-10-07 11:37:04.769 INFO 3492 --- [ main] com.durgasoft.HelloappApplication

: Starting HelloappApplication on DESKTOP-LTICM7V with PID 3492

(D:\mywebapps\helloapp\target\classes started by Nagoor in D:\mywebapps\helloapp)

2019-10-07 11:37:04.771 INFO 3492 --- [ main] com.durgasoft.HelloappApplication

: No active profile set, falling back to default profiles: default

2019-10-07 11:37:05.744 INFO 3492 --- [ main]

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 5555 (http)

2019-10-07 11:37:05.769 INFO 3492 --- [ main]

o.apache.catalina.core.StandardService : Starting service [Tomcat]

2019-10-07 11:37:05.769 INFO 3492 --- [ main]

org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.26]

2019-10-07 11:37:05.876 INFO 3492 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] :

Initializing Spring embedded WebApplicationContext

2019-10-07 11:37:05.876 INFO 3492 --- [ main] o.s.web.context.ContextLoader

: Root WebApplicationContext: initialization completed in 1063 ms

2019-10-07 11:37:06.098 INFO 3492 --- [ main]

o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService

'applicationTaskExecutor'

2019-10-07 11:37:06.279 INFO 3492 --- [ main]

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 5555 (http) with

context path ''

2019-10-07 11:37:06.283 INFO 3492 --- [ main] com.durgasoft.HelloappApplication

: Started HelloappApplication in 1.89 seconds (JVM running for 2.8)

HelloApp from Spring Boot initializer

e)If we want to prepare Spring Boot application through Web Client then prepare

Controller class with handler method and execute that:

EX: HelloController.java

-------------------------

package com.durgasoft.controller;

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

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

@RestController

public class HelloController {

@RequestMapping("/hello")

public String sayhello() {

return "<h1>Hello User!</h1>";

}

}

To run this , first we have to execute "HelloappApplication" then open browser and use the

following URL.

http://localhost:5555/hello

• Spring Boot CLI[Command Line Interface]:

-------------------------------------------------------------

--> Spring Boot CLI(Command Line Interface) is a Spring Boot software to run and test

Spring Boot applications from command prompt. When we run Spring Boot applications

using CLI, then it internally uses Spring Boot Starter and Spring Boot AutoConfigurate

components to resolve all dependencies and execute the application

--> Spring Boot internally contains Groovy and Grape (JAR Dependency Manager) to add

Spring Boot Defaults and resolve all dependencies automatically.

--> To use Spring Boot CLI we have to use the following steps.

• Download and Install Spring Boot CLI.
• Prepare Groovy Script Code.
• Run Groovy Script code through Spring Boot CLI.
• Download and Install Spring Boot CLI:

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a)Open the link in Browser address bar "https://docs.spring.io/spring-

boot/docs/current/reference/html/getting-started-installing- spring-boot.html#getting-

started-installing-the-cli". or else search for it in Google.

b)click on "spring-boot-cli-2.1.9.RELEASE-bin.zip" link under Manual Installation.

c)Copy the downloaded ""spring-boot-cli-2.1.9.RELEASE-bin.zip"" in C drive and extract it

then we will find "spring-2.1.9.RELEASE" folder in C Driver.

d)Set "path" environment variable to "C:\spring-2.1.9.RELEASE\bin" location.

set path=%path%;C:\spring-2.1.9.RELEASE\bin;

e)Check whether Spring command is running or not in Command prompt.