Maven Cheatsheet

Überblick

Apache Maven ist ein Build Automation und Projektmanagement-Tool, das in erster Linie für Java-Projekte verwendet wird. Es verwendet XML-basierte Konfigurationsdateien (POM) und folgt dem Convention-over-configuration Prinzip.

Installation

Paketmanager

# macOS
brew install maven

# Ubuntu/Debian
sudo apt install maven

# CentOS/RHEL
sudo yum install maven

# Windows (Chocolatey)
choco install maven

# Manual installation
wget https://archive.apache.org/dist/maven/maven-3/3.9.0/binaries/apache-maven-3.9.0-bin.tar.gz
tar -xzf apache-maven-3.9.0-bin.tar.gz
export PATH=$PATH:/path/to/apache-maven-3.9.0/bin
```_

### Überprüfung
```bash
mvn --version
mvn -v
```_

## Projektstruktur

### Standard Directory Layout

project/ ├── pom.xml ├── src/ │ ├── main/ │ │ ├── java/ │ │ ├── resources/ │ │ └── webapp/ │ └── test/ │ ├── java/ │ └── resources/ ├── target/ └── README.md ```_

Basic POM (pom.xml)

Minimaler POM

```xml

4.0.0

<groupId>com.example</groupId>
<artifactId>my-app</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>

<name>My Application</name>
<description>A sample Maven project</description>

<properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.13.2</version>
        <scope>test</scope>
    </dependency>
</dependencies>

```_

Vollständiges POM Beispiel

```xml

4.0.0

<groupId>com.example</groupId>
<artifactId>my-app</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>

<name>My Application</name>
<description>A comprehensive Maven project example</description>
<url>https://github.com/example/my-app</url>

<properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>5.3.21</spring.version>
    <junit.version>5.8.2</junit.version>
</properties>

<dependencies>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>$\\\\{spring.version\\\\}</version>
    </dependency>

    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter</artifactId>
        <version>$\\\\{junit.version\\\\}</version>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.10.1</version>
            <configuration>
                <source>11</source>
                <target>11</target>
            </configuration>
        </plugin>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>3.0.0-M7</version>
        </plugin>
    </plugins>
</build>

```_

Abhängigkeiten

Abhängigkeitsbereiche

```xml

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.2</version>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.29</version>
    <scope>runtime</scope>
</dependency>

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>

<dependency>
    <groupId>com.example</groupId>
    <artifactId>custom-lib</artifactId>
    <version>1.0</version>
    <scope>system</scope>
    <systemPath>$\\\\{project.basedir\\\\}/lib/custom-lib.jar</systemPath>
</dependency>

```_

Abhängigkeitsmanagement

```xml

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>2.7.0</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.12.0</version>
    </dependency>
</dependencies>

```_

Ausschlüsse

xml <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>5.3.21</version> <exclusions> <exclusion> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> </exclusion> </exclusions> </dependency>_

Lebenszyklus aufbauen

Default Lifecycle Phasen

```bash

Validate

mvn validate

Compile

mvn compile

Test

mvn test

Package

mvn package

Integration test

mvn integration-test

Verify

mvn verify

Install

mvn install

Deploy

mvn deploy

Clean

mvn clean ```_

Gemeinsame Phasenkombinationen

```bash

Clean and compile

mvn clean compile

Clean and package

mvn clean package

Clean, test, and install

mvn clean test install

Skip tests

mvn clean package -DskipTests

Skip test compilation

mvn clean package -Dmaven.test.skip=true ```_

Plugins

Core Plugins

```xml

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.10.1</version>
        <configuration>
            <source>11</source>
            <target>11</target>
            <encoding>UTF-8</encoding>
        </configuration>
    </plugin>

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.0.0-M7</version>
        <configuration>
            <includes>
                <include>**/*Test.java</include>
                <include>**/*Tests.java</include>
            </includes>
        </configuration>
    </plugin>

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-failsafe-plugin</artifactId>
        <version>3.0.0-M7</version>
        <executions>
            <execution>
                <goals>
                    <goal>integration-test</goal>
                    <goal>verify</goal>
                </goals>
            </execution>
        </executions>
    </plugin>

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-jar-plugin</artifactId>
        <version>3.2.2</version>
        <configuration>
            <archive>
                <manifest>
                    <mainClass>com.example.Main</mainClass>
                    <addClasspath>true</addClasspath>
                </manifest>
            </archive>
        </configuration>
    </plugin>
</plugins>

```_

Beliebte Third-Party Plugins

```xml

org.springframework.boot spring-boot-maven-plugin 2.7.0 repackage

org.apache.maven.plugins maven-shade-plugin 3.3.0 package shade com.example.Main

org.jacoco jacoco-maven-plugin 0.8.7 prepare-agent report test report

com.spotify dockerfile-maven-plugin 1.4.13 $\\{docker.image.prefix\\}/$\\{project.artifactId\\} $\\{project.version\\} ```_

Profile

Umweltprofile

```xml

<profile>
    <id>dev</id>
    <activation>
        <activeByDefault>true</activeByDefault>
    </activation>
    <properties>
        <database.url>jdbc:h2:mem:testdb</database.url>
        <log.level>DEBUG</log.level>
    </properties>
    <dependencies>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <version>2.1.212</version>
        </dependency>
    </dependencies>
</profile>

<profile>
    <id>prod</id>
    <properties>
        <database.url>jdbc:mysql://prod-server:3306/mydb</database.url>
        <log.level>INFO</log.level>
    </properties>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.29</version>
        </dependency>
    </dependencies>
</profile>

<profile>
    <id>test</id>
    <build>
        <plugins>
            <plugin>
                <groupId>org.jacoco</groupId>
                <artifactId>jacoco-maven-plugin</artifactId>
                <version>0.8.7</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>prepare-agent</goal>
                        </goals>
                    </execution>
                    <execution>
                        <id>report</id>
                        <phase>test</phase>
                        <goals>
                            <goal>report</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</profile>

```_

Aktivierungsbedingungen

```xml windows windows

java11 11

property-based environment production

```_

Multi-Module Projekte

Elternteil POM

```xml

4.0.0

<groupId>com.example</groupId>
<artifactId>my-parent</artifactId>
<version>1.0.0</version>
<packaging>pom</packaging>

<name>My Parent Project</name>

<modules>
    <module>core</module>
    <module>web</module>
    <module>api</module>
</modules>

<properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <spring.version>5.3.21</spring.version>
</properties>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-framework-bom</artifactId>
            <version>$\\\\{spring.version\\\\}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<build>
    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.10.1</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

```_

Kindermodul POM

```xml

4.0.0

<parent>
    <groupId>com.example</groupId>
    <artifactId>my-parent</artifactId>
    <version>1.0.0</version>
</parent>

<artifactId>core</artifactId>
<packaging>jar</packaging>

<name>Core Module</name>

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
    </dependency>

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

```_

Verwendung der Befehlszeile

Grundlegende Befehle

```bash

Create new project

mvn archetype:generate -DgroupId=com.example -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

Compile

mvn compile

Test

mvn test

Package

mvn package

Install to local repository

mvn install

Deploy to remote repository

mvn deploy

Clean

mvn clean ```_

Erweiterte Optionen

```bash

Activate profile

mvn clean package -Pprod

Set properties

mvn clean package -Denvironment=production -Dlog.level=INFO

Skip tests

mvn clean package -DskipTests

Offline mode

mvn clean package -o

Debug mode

mvn clean package -X

Quiet mode

mvn clean package -q

Update snapshots

mvn clean package -U

Parallel builds

mvn clean package -T 4

Resume from specific module

mvn clean package -rf :web-module ```_

Abhängigkeitsbefehle

```bash

Show dependency tree

mvn dependency:tree

Show effective POM

mvn help:effective-pom

Show effective settings

mvn help:effective-settings

Analyze dependencies

mvn dependency:analyze

Copy dependencies

mvn dependency:copy-dependencies

Resolve dependencies

mvn dependency:resolve

Show dependency sources

mvn dependency:sources

Show dependency javadocs

mvn dependency:resolve -Dclassifier=javadoc ```_

Einstellungen und Konfiguration

Einstellungen.xml (~/.m2/settings.xml)

```xml

<localRepository>$\\\\{user.home\\\\}/.m2/repository</localRepository>

<servers>
    <server>
        <id>nexus</id>
        <username>admin</username>
        <password>admin123</password>
    </server>
</servers>

<mirrors>
    <mirror>
        <id>central-mirror</id>
        <name>Central Repository Mirror</name>
        <url>https://repo1.maven.org/maven2</url>
        <mirrorOf>central</mirrorOf>
    </mirror>
</mirrors>

<profiles>
    <profile>
        <id>nexus</id>
        <repositories>
            <repository>
                <id>nexus</id>
                <url>http://localhost:8081/repository/maven-public/</url>
                <releases>
                    <enabled>true</enabled>
                </releases>
                <snapshots>
                    <enabled>true</enabled>
                </snapshots>
            </repository>
        </repositories>
    </profile>
</profiles>

<activeProfiles>
    <activeProfile>nexus</activeProfile>
</activeProfiles>

```_

Repository Konfiguration

```xml central Central Repository https://repo1.maven.org/maven2 default false

<repository>
    <id>spring-releases</id>
    <name>Spring Releases</name>
    <url>https://repo.spring.io/release</url>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
</repository>

central Central Repository https://repo1.maven.org/maven2 default false never ```_

Best Practices

POM Organisation

```xml

<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>my-app</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>

<name>My Application</name>
<description>Application description</description>
<url>https://github.com/example/my-app</url>

<properties>

</properties>

<dependencyManagement>

</dependencyManagement>

<dependencies>

</dependencies>

<build>

</build>

<profiles>

</profiles>

```_

Versionsmanagement

```xml

<spring.version>5.3.21</spring.version>
<junit.version>5.8.2</junit.version>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>

org.springframework spring-framework-bom $\\{spring.version\\} pom import ```_

Fehlerbehebung

Gemeinsame Themen

```bash

Clear local repository

rm -rf ~/.m2/repository

Force update snapshots

mvn clean package -U

Debug dependency resolution

mvn dependency:tree -Dverbose

Check for dependency conflicts

mvn dependency:analyze

Validate POM

mvn validate

Check effective POM

mvn help:effective-pom ```_

Debug Mode

```bash

Enable debug output

mvn clean package -X

Show version information

mvn --version

Show help

mvn help:help ```_

Ressourcen

• offizielle Dokumentation: maven.apache.org
• POM Referenz: [maven.apache.org/pom.html](https://_LINK_4___
• Plugin List: maven.apache.org/plugins
• *Zentral Repository: [search.maven.org](__LINK_4___