Develop Reference

How do I create an executable jar for my webapp with Maven?

Backgound
I develop a webapp using a REST Interface with Spring. Normally I develop and execute my software with Eclipse. When my program has been started I enter localhost:8080/RESTPath in Chrome to access RESTPath with my program.
Issue
Now I want to build and execute my program with Maven instead with a executeble jar. The issue is that my knowledge with Maven is limited so I'm not sure how to do. Of course I have googled my issue and I have tested some examples but without succes. So far I think I should use the plugin tomcat7-maven-plugin in my POM.xml to generate a jar to execute with java -jar file.jar. I have followed the example with a webapp using tomcat7-maven-plugin but the jar file is never generated: https://www.baeldung.com/executable-jar-with-maven.
My POM:
<?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>2.6.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<!-- My project -->
<groupId>tobbe</groupId>
<artifactId>stocks-rest</artifactId>
<packaging>jar</packaging>
<version>1.0.2-SNAPSHOT</version>
<properties>
<java.version>17</java.version>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<!-- My projects -->
<dependency>
<groupId>tobbe</groupId>
<artifactId>Stocks_Backend</artifactId>
<version>1.0.2-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>tobbe</groupId>
<artifactId>Other</artifactId>
<version>1.0.2-SNAPSHOT</version>
</dependency>
</dependencies>
</project>
Question
how should my POM look like a how should I build with Maven (i.e. mvn clean compile) to create an executable jar?

<?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>2.6.2</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</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>
You are missing build section in your pom. When you execute mvn clean package you will get the JAR File in the target folder

spring initializer in spring boot application

I have generated a spring boot application with spring-initializer. when im building the project it gives an unknown error in pom.xml file.
Why is this happening and how to reslove it?error with the pom.xml
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.research</groupId>
<artifactId>patients-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>patients-api</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</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>

it is not an error to worry about. Spring Boot 2.1.5.RELEASE has release just a week back and probably the IDE you are using for example STS may not be the latest one.
You have 2 options:
update your IDE & Maven and to the latest version [OR]
Simply change version <version>2.1.5.RELEASE</version> to <version>2.1.4.RELEASE</version> and do a Maven update on the project.
I had a similar issue and I fixed with the above options.
Hope this helps.

Spring boot downloads jsp file, not renders

I have a simple spring-boot application and I have a problem. Instead of rendering a jsp page, it is downloaded. I have seen some Stack Overflow questions about this but none of them was useful.
Folder structure looks like this:
This is application.properties file:
server.port=8089
spring.mvc.view.prefix=/jsp/
spring.mvc.view.suffix=.jsp
spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
spring.datasource.url=jdbc:oracle:thin:#localhost:1521:testing
spring.datasource.platform=oracle
spring.datasource.username=ANONYMOUS
spring.datasource.password=alex
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
This is pom.xml file:
<?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>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.1.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<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>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/ojdbc8.jar</systemPath>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
I am using Visual Studio Code and I run this app with this command:
./mvnw spring-boot:run
Last lines in VS Code terminal looks like this:
What can be problem?

Java spring error persistence imports are not working

I am creating a simple Spring boot project. When I try and use #Entity and #Id etc. I get a cannot resolve error why is this? Have I not installed the correct version of something. My Imports don't seem to be working and are highlighted in red. I am new to spring. I have attachedThe error as an image.
The error is Package javax.persistence does not exist??
My Pom.xml:
<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.JohnSharp</groupId>
<artifactId>Guestbooknew</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Guestbooknew</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

Right click on your project -> Maven -> Update project.
For intellij:
Right click on your project > Maven > Reimport

How to package a maven multi-module properly?

I'm building a multi-module rest service with Maven and Spring Boot that will be published on a WebLogic Server, and I'm a bit confuse about how to configure the packaging of the application modules.
My current structure is:
/application
/main (main mehtod for spring-boot)
/api
/service
/dao
The parent project (application folder) is set up as pom packaging, but child projects I'm not sure how to configure it. I believe the correct way would be packaging like .jar file, but i saw some examples on the internet of Java projects with Maven multi-modules defined as war.
can someone tell me what's the correct way to define the child modules packaging in this case?
My parent pom:
<?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.radarveicular</groupId>
<artifactId>radarveicular-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
<javax.inject.version>1</javax.inject.version>
</properties>
<modules>
<module>radarveicular-api</module>
<module>radarveicular-service</module>
<module>radarveicular-main</module>
<module>radarveicular-dao</module>
</modules>
<build>
<plugins>
<plugin>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>true</downloadJavadocs>
<wtpversion>2.0</wtpversion>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
main pom:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>radarveicular-main</artifactId>
<dependencies>
<dependency>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-api</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<!-- Spring Framework -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-undertow</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
api pom:
<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>
<parent>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>radarveicular-api</artifactId>
<dependencies>
<dependency>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
service pom:
<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>
<parent>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>radarveicular-service</artifactId>
<dependencies>
<dependency>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-dao</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.7.RELEASE</version>
</dependency>
</dependencies>
</project>
dao pom:
<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>
<parent>
<groupId>com.radarveicular</groupId>
<artifactId>radarveicular-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>radarveicular-dao</artifactId>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.7.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.30</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
</project>

I think your problem is that your parent pom.xml shouldn't handle your spring boot project. Meaning, you should have this in it :
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
I recommend that your pom.xml parent only handles your modules and dependencies as pom packaging :
Packaging
<packaging>pom</packaging>
Modules
<modules>
<module>radarveicular-api</module>
<module>radarveicular-service</module>
<module>radarveicular-main</module>
<module>radarveicular-dao</module>
</modules>
Then, you will have your module radarveicular-main with the spring boot parent :
Parent
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
Packaging
<packaging>war</packaging>
I hope this will help you. =)

I feel your question is more towards designing part of multi module.
Multi module management of application can depend on various things.
One thing could be if you want to deploy each sub module as separate module/service based, which can be turned off/on based on need. In that case it would help you if you build each of module as separate war and deploy them separately.
If you have to deploy it as a single war than most straight forward would to create all dependent modules as jar and include them in parent project. In this way a single war will be deployed.
You can have a hybrid approach of above two.
Hopefully i have understood your question correctly. :)
Happy coding!!