Plugins in Maven and POM.xml
Solution 1:
<project>
<groupId>org.koshik.javabrains</groupId>
<artifactId>JarName</artifactId> (A fldernamed JarName was created)
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>JarName</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.jibx</groupId>
<artifactId>jibx-maven-plugin</artifactId>
<version>1.2.4</version>
<executions>
<execution>
<goals>
<goal>bind</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
You can also place plugins in the <build>
section of <profile>
if you use maven profiles. The order doesn't matter.
Solution 2:
A late clarification on two important points
Where to place plugin
A plugin
should indeed be added in most of the cases within the build
/plugins
section, however there is an important difference between placing it within plugins
against placing it within pluginManagement
/plugins
.
This misunderstanding is often the cause of a non invoked plugin in Maven or an harder troubleshooting:
- Plugins under
build
/plugins
are directly part of the default Maven build, if they specify anexecution
or if they configure something for the default build (see below) -
Plugins under
build
/pluginManagement
/plugins
are not necessarely part of the default Maven build, that is, is a management, it's an hint to maven: it you happen to use this plugin, then please use the version, the configuration, the executions I specify here, in this management.But what happen to use means? Means: if the same plugin is also present in the
build
/plugins
section, then apply this management (and only then it will be effective); or if the plugin is invoked by default by Maven, then also apply it.But how is a plugin invoked by default? That's part of the main philosophy behind maven: convention over configuration. By convention, when you specify a certain
packaging
(defaultjar
, but it can bewar
for example), you want certain plugins to be invoked. To build ajar
, by default invoke themaven-jar-plugin
; to build awar
, by default invoke themaven-war-plugin
and so on. So, if you specify a plugin configuration in thebuild
/pluginManagement
/plugin
for a plugin which has a default binding to the Maven build, then it will be also be used.
Ordering
Concerning the ordering of sections within the pom.xml
file, a further clarification is required: it's indeed irrelevant in most of the cases, however the order of plugin
element wihtin the build
/plugins
section may be important. Since Maven 3.0.3 (MNG-2258
), different plugin executions attached to the same Maven phase will be invoked in their order of declaration in the pom.xml
file. That is, ordering is important in this case, since it may affect the behavior of the build.
Additionally, also order of dependency
declarations may affect your build towards Dependency Mediation, that is, the first declared dependency wins in case of conflict against a transitive dependency. So, once again, ordering is important in certain cases.
Last but not least, although ordering is not important for other sections of the pom.xml
file, good habit is to follow official Maven recommendations and, as a simplified version, follow this order of declaration:
<project>
<modelVersion/>
<parent/>
<groupId/>
<artifactId/>
<version/>
<packaging/>
<properties/>
<dependencyManagement/>
<dependencies/>
<build/>
<reporting/>
<profiles/>
</project>
The sortpom-maven-plugin
can also be used to automatically apply this standard ordering, simply invoking the following on the concerned pom.xml
file:
mvn com.github.ekryd.sortpom:sortpom-maven-plugin:2.5.0:sort \
-Dsort.keepBlankLines -Dsort.predefinedSortOrder=recommended_2008_06
For further reading:
- Stack Overflow: Maven: what is pluginManagement?
- Official Maven doc: Maven POM Reference, PluginManagement
- Official Maven default bindings
- Official Maven doc: Dependency Mediation
- Official Maven doc: Maven Code Style And Code Conventions
Solution 3:
<plugin>
should be placed into <plugins>
section which should be placed into <build>
or <pluginManagement>
section.
The order of <dependency>
or <build>
section doesn't matter.
The full reference about pom.xml is here: http://maven.apache.org/pom.html