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

Maven: "Could not find artifact package:jar:1.0-SNAPSHOT"?

I've tried installing a Spring project, and had one created from start.spring.io. However, when trying to run mvn clean install, I have run into errors:
Could not find artifact com.sof:game-mix:jar:1.0-SNAPSHOT
I know this is has happened to others, and I've checked these threads for more information but unfortunately my attempts to replicate their solutions haven't worked for me.
Here is a link to my project, for anyone who wishes to replicate the project and see if mvn clean install might work for them. Otherwise, the code for my pom.xml files is below
I have three pom.xml files:
Root 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>
<groupId>com.sof</groupId>
<artifactId>game-mix</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<parent>
<artifactId>spring-boot-starter-parent</artifactId>
<groupId>org.springframework.boot</groupId>
<version>2.0.3.RELEASE</version>
<relativePath/>
</parent>
<modules>
<module>core</module>
<module>web</module>
</modules>
<properties>
<java.version>13</java.version>
</properties>
</project>
My web module's 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">
<parent>
<artifactId>game-mix</artifactId>
<groupId>com.sof</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>web</artifactId>
<dependencies>
<!--dependency for our core module-->
<dependency>
<groupId>com.sof</groupId>
<artifactId>game-mix</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!--dependency for spring boot-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--Thymeleaf Dependency-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--Spring Boot devtools-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.12</version>
<scope>compile</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
And my core module's 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">
<parent>
<artifactId>game-mix</artifactId>
<groupId>com.sof</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>core</artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
</project>
Where exactly am I going wrong? I'd appreciate any assistance

I deleted my first answer because I did not read your POMs thoroughly enough.
com.sof:game-mix:jar:1.0-SNAPSHOT is your parent POM. You cannot reference it as a <dependency>.

Creating multi module project using Intellij & Maven

I have a project structure which has a core tool and a REST API to interact and configure that tool.
I have a package structure like this:
com.example.api -> contains API definitions
com.example.commons -> contains module common to both core and api
com.exmaple.core -> contains the core module
This is primarily a Spring Boot application and both will run in different containers. So the API and the Core jar will be different.
How do I create a multi-module project with this structure so that I can also use the commons module in both the sub packages(core & api).
Suggestions on how to configure Maven and IntelliJ in such an environment?
Is my pattern right? Are there other well known patterns for this kind of project structure?

You can have a multi Maven module project as you wish. Here's an example on how you should configure your modules:
Create a parent pom.xml as follows (note that I am not adding spring-boot-starter-parent as a parent to the project, I am bringing in the Spring Boot dependencies with spring-boot-dependencies):
<?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.example</groupId>
<artifactId>parent</artifactId>
<packaging>pom</packaging>
<version>1.0.0-SNAPSHOT</version>
<modules>
<module>example-commons</module>
<module>example-core</module>
<module>example-api</module>
</modules>
<dependencyManagement>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-dependencies -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>1.5.3.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>1.5.3.RELEASE</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>1.5.3.RELEASE</version>
</dependency>
</dependencies>
</project>
And a non executable module's pom.xml would be like:
<?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">
<parent>
<artifactId>parent</artifactId>
<groupId>com.example</groupId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>example-commons</artifactId>
</project>
whereas an executable module's pom.xml would be like (note the spring-boot-maven-plugin is present only here for this 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">
<parent>
<artifactId>parent</artifactId>
<groupId>com.example</groupId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>example-core</artifactId>
<build>
<plugins>
<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-maven-plugin -->
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.3.RELEASE</version>
<configuration>
<executable>true</executable>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>com.example</groupId>
<artifactId>example-commons</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
</dependencies>
</project>

SpringApplication.run(HelloWorldExampleApplication.class, args);

the error is in the following line of code-
SpringApplication.run(HelloWorldExampleApplication.class, args);
it says-
Multiple markers at this line
- The type org.springframework.context.ConfigurableApplicationContext cannot be resolved. It is indirectly referenced
from required .class files
- The method run(Class<?>, String...) from the type SpringApplication refers to the missing type
ConfigurableApplicationContext
I've tried running command "mvn dependency:purge-local-repository" and it says mvn not recognised as int/ext command.
i'm using springboot sts plugin in eclipse IDE.
pls. help as i'm a beginner.
pom 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>
<groupId>com.Ideng</groupId>
<artifactId>helloworld</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>HelloWorldExample</name>
<description>hello world example</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.0.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>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>

i changed the spring version from 2.0.0 to 2.0.1 SNAPSHOT while creating the project from start and it worked

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!!