The Spring Boot Maven Plugin provides Spring Boot support in Maven, letting you package executable jar or war archives and run an application “in-place”. To use it, you must use Maven 3.2 (or later).
Note | |
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See the Spring Boot Maven Plugin Site for complete plugin documentation. |
To use the Spring Boot Maven Plugin, include the appropriate XML in the plugins
section of your pom.xml
, as shown in the following example:
<?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> <!-- ... --> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.1.9.RELEASE</version> <executions> <execution> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>
The preceding configuration repackages a jar or war that is built during the package
phase of the Maven lifecycle.
The following example shows both the repackaged jar as well as the original jar in the target
directory:
$ mvn package $ ls target/*.jar target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original
If you do not include the <execution/>
configuration, as shown in the prior example, you can run the plugin on its own (but only if the package goal is used as well), as shown in the following example:
$ mvn package spring-boot:repackage $ ls target/*.jar target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original
If you use a milestone or snapshot release, you also need to add the appropriate pluginRepository
elements, as shown in the following listing:
<pluginRepositories> <pluginRepository> <id>spring-snapshots</id> <url>https://repo.spring.io/snapshot</url> </pluginRepository> <pluginRepository> <id>spring-milestones</id> <url>https://repo.spring.io/milestone</url> </pluginRepository> </pluginRepositories>
Once spring-boot-maven-plugin
has been included in your pom.xml
, it automatically tries to rewrite archives to make them executable by using the spring-boot:repackage
goal.
You should configure your project to build a jar or war (as appropriate) by using the usual packaging
element, as shown in the following example:
<?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"> <!-- ... --> <packaging>jar</packaging> <!-- ... --> </project>
Your existing archive is enhanced by Spring Boot during the package
phase.
The main class that you want to launch can be specified either by using a configuration option, as shown below, or by adding a Main-Class
attribute to the manifest.
If you do not specify a main class, the plugin searches for a class with a public static void main(String[] args)
method.
<plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <mainClass>com.example.app.Main</mainClass> </configuration> </plugin>
To build and run a project artifact, you can type the following:
$ mvn package $ java -jar target/mymodule-0.0.1-SNAPSHOT.jar
To build a war file that is both executable and deployable into an external container, you need to mark the embedded container dependencies as “provided”, as shown in the following example:
<?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"> <!-- ... --> <packaging>war</packaging> <!-- ... --> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <scope>provided</scope> </dependency> <!-- ... --> </dependencies> </project>
Tip | |
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See the “Section 92.1, “Create a Deployable War File”” section for more details on how to create a deployable war file. |
Advanced configuration options and examples are available in the plugin info page.