13. Build systems

It is strongly recommended that you choose a build system that supports dependency management, and one that can consume artifacts published to the “Maven Central” repository. We would recommend that you choose Maven or Gradle. It is possible to get Spring Boot to work with other build systems (Ant for example), but they will not be particularly well supported.

13.1 Dependency management

Each release of Spring Boot provides a curated list of dependencies it supports. In practice, you do not need to provide a version for any of these dependencies in your build configuration as Spring Boot is managing that for you. When you upgrade Spring Boot itself, these dependencies will be upgraded as well in a consistent way.

[Note]Note

You can still specify a version and override Spring Boot’s recommendations if you feel that’s necessary.

The curated list contains all the spring modules that you can use with Spring Boot as well as a refined list of third party libraries. The list is available as a standard Bills of Materials (spring-boot-dependencies) and additional dedicated support for Maven and Gradle are available as well.

[Warning]Warning

Each release of Spring Boot is associated with a base version of the Spring Framework so we highly recommend you to not specify its version on your own.

13.2 Maven

Maven users can inherit from the spring-boot-starter-parent project to obtain sensible defaults. The parent project provides the following features:

On the last point: since the default config files accept Spring style placeholders (${…​}) the Maven filtering is changed to use @[email protected] placeholders (you can override that with a Maven property resource.delimiter).

13.2.1 Inheriting the starter parent

To configure your project to inherit from the spring-boot-starter-parent simply set the parent:

<!-- Inherit defaults from Spring Boot -->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.8.RELEASE</version>
</parent>
[Note]Note

You should only need to specify the Spring Boot version number on this dependency. If you import additional starters, you can safely omit the version number.

With that setup, you can also override individual dependencies by overriding a property in your own project. For instance, to upgrade to another Spring Data release train you’d add the following to your pom.xml.

<properties>
    <spring-data-releasetrain.version>Fowler-SR2</spring-data-releasetrain.version>
</properties>
[Tip]Tip

Check the spring-boot-dependencies pom for a list of supported properties.

13.2.2 Using Spring Boot without the parent POM

Not everyone likes inheriting from the spring-boot-starter-parent POM. You may have your own corporate standard parent that you need to use, or you may just prefer to explicitly declare all your Maven configuration.

If you don’t want to use the spring-boot-starter-parent, you can still keep the benefit of the dependency management (but not the plugin management) by using a scope=import dependency:

<dependencyManagement>
     <dependencies>
        <dependency>
            <!-- Import dependency management from Spring Boot -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>1.3.8.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

That setup does not allow you to override individual dependencies using a property as explained above. To achieve the same result, you’d need to add an entry in the dependencyManagement of your project before the spring-boot-dependencies entry. For instance, to upgrade to another Spring Data release train you’d add the following to your pom.xml.

<dependencyManagement>
    <dependencies>
        <!-- Override Spring Data release train provided by Spring Boot -->
        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-releasetrain</artifactId>
            <version>Fowler-SR2</version>
            <scope>import</scope>
            <type>pom</type>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>1.3.8.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
[Note]Note

In the example above, we specify a BOM but any dependency type can be overridden that way.

13.2.3 Changing the Java version

The spring-boot-starter-parent chooses fairly conservative Java compatibility. If you want to follow our recommendation and use a later Java version you can add a java.version property:

<properties>
    <java.version>1.8</java.version>
</properties>

13.2.4 Using the Spring Boot Maven plugin

Spring Boot includes a Maven plugin that can package the project as an executable jar. Add the plugin to your <plugins> section if you want to use it:

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>
[Note]Note

If you use the Spring Boot starter parent pom, you only need to add the plugin, there is no need for to configure it unless you want to change the settings defined in the parent.

13.3 Gradle

Gradle users can directly import “starter POMs” in their dependencies section. Unlike Maven, there is no “super parent” to import to share some configuration.

apply plugin: 'java'

repositories {
    jcenter()
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web:1.3.8.RELEASE")
}

The spring-boot-gradle-plugin is also available and provides tasks to create executable jars and run projects from source. It also provides dependency management that, among other capabilities, allows you to omit the version number for any dependencies that are managed by Spring Boot:

buildscript {
    repositories {
        jcenter()
    }

    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.8.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'spring-boot'

repositories {
    jcenter()
}

dependencies {
    compile("org.springframework.boot:spring-boot-starter-web")
    testCompile("org.springframework.boot:spring-boot-starter-test")
}

13.4 Ant

It is possible to build a Spring Boot project using Apache Ant+Ivy. The spring-boot-antlib “AntLib” module is also available to help Ant create executable jars.

To declare dependencies a typical ivy.xml file will look something like this:

<ivy-module version="2.0">
    <info organisation="org.springframework.boot" module="spring-boot-sample-ant" />
    <configurations>
        <conf name="compile" description="everything needed to compile this module" />
        <conf name="runtime" extends="compile" description="everything needed to run this module" />
    </configurations>
    <dependencies>
        <dependency org="org.springframework.boot" name="spring-boot-starter"
            rev="${spring-boot.version}" conf="compile" />
    </dependencies>
</ivy-module>

A typical build.xml will look like this:

<project
    xmlns:ivy="antlib:org.apache.ivy.ant"
    xmlns:spring-boot="antlib:org.springframework.boot.ant"
    name="myapp" default="build">

    <property name="spring-boot.version" value="1.3.0.BUILD-SNAPSHOT" />

    <target name="resolve" description="--> retrieve dependencies with ivy">
        <ivy:retrieve pattern="lib/[conf]/[artifact]-[type]-[revision].[ext]" />
    </target>

    <target name="classpaths" depends="resolve">
        <path id="compile.classpath">
            <fileset dir="lib/compile" includes="*.jar" />
        </path>
    </target>

    <target name="init" depends="classpaths">
        <mkdir dir="build/classes" />
    </target>

    <target name="compile" depends="init" description="compile">
        <javac srcdir="src/main/java" destdir="build/classes" classpathref="compile.classpath" />
    </target>

    <target name="build" depends="compile">
        <spring-boot:exejar destfile="build/myapp.jar" classes="build/classes">
            <spring-boot:lib>
                <fileset dir="lib/runtime" />
            </spring-boot:lib>
        </spring-boot:exejar>
    </target>
</project>
[Tip]Tip

See the Section 78.8, “Build an executable archive from Ant without using spring-boot-antlib” “How-to” if you don’t want to use the spring-boot-antlib module.

13.5 Starter POMs

Starter POMs are a set of convenient dependency descriptors that you can include in your application. You get a one-stop-shop for all the Spring and related technology that you need, without having to hunt through sample code and copy paste loads of dependency descriptors. For example, if you want to get started using Spring and JPA for database access, just include the spring-boot-starter-data-jpa dependency in your project, and you are good to go.

The starters contain a lot of the dependencies that you need to get a project up and running quickly and with a consistent, supported set of managed transitive dependencies.

The following application starters are provided by Spring Boot under the org.springframework.boot group:

Table 13.1. Spring Boot application starters

NameDescription

spring-boot-starter

The core Spring Boot starter, including auto-configuration support, logging and YAML.

spring-boot-starter-actuator

Production ready features to help you monitor and manage your application.

spring-boot-starter-amqp

Support for the “Advanced Message Queuing Protocol” via spring-rabbit.

spring-boot-starter-aop

Support for aspect-oriented programming including spring-aop and AspectJ.

spring-boot-starter-artemis

Support for “Java Message Service API” via Apache Artemis.

spring-boot-starter-batch

Support for “Spring Batch” including HSQLDB database.

spring-boot-starter-cache

Support for Spring’s Cache abstraction.

spring-boot-starter-cloud-connectors

Support for “Spring Cloud Connectors” which simplifies connecting to services in cloud platforms like Cloud Foundry and Heroku.

spring-boot-starter-data-elasticsearch

Support for the Elasticsearch search and analytics engine including spring-data-elasticsearch.

spring-boot-starter-data-gemfire

Support for the GemFire distributed data store including spring-data-gemfire.

spring-boot-starter-data-jpa

Support for the “Java Persistence API” including spring-data-jpa, spring-orm and Hibernate.

spring-boot-starter-data-mongodb

Support for the MongoDB NoSQL Database, including spring-data-mongodb.

spring-boot-starter-data-rest

Support for exposing Spring Data repositories over REST via spring-data-rest-webmvc.

spring-boot-starter-data-solr

Support for the Apache Solr search platform, including spring-data-solr.

spring-boot-starter-freemarker

Support for the FreeMarker templating engine.

spring-boot-starter-groovy-templates

Support for the Groovy templating engine.

spring-boot-starter-hateoas

Support for HATEOAS-based RESTful services via spring-hateoas.

spring-boot-starter-hornetq

Support for “Java Message Service API” via HornetQ.

spring-boot-starter-integration

Support for common spring-integration modules.

spring-boot-starter-jdbc

Support for JDBC databases.

spring-boot-starter-jersey

Support for the Jersey RESTful Web Services framework.

spring-boot-starter-jta-atomikos

Support for JTA distributed transactions via Atomikos.

spring-boot-starter-jta-bitronix

Support for JTA distributed transactions via Bitronix.

spring-boot-starter-mail

Support for javax.mail.

spring-boot-starter-mobile

Support for spring-mobile.

spring-boot-starter-mustache

Support for the Mustache templating engine.

spring-boot-starter-redis

Support for the REDIS key-value data store, including spring-redis.

spring-boot-starter-security

Support for spring-security.

spring-boot-starter-social-facebook

Support for spring-social-facebook.

spring-boot-starter-social-linkedin

Support for spring-social-linkedin.

spring-boot-starter-social-twitter

Support for spring-social-twitter.

spring-boot-starter-test

Support for common test dependencies, including JUnit, Hamcrest and Mockito along with the spring-test module.

spring-boot-starter-thymeleaf

Support for the Thymeleaf templating engine, including integration with Spring.

spring-boot-starter-velocity

Support for the Velocity templating engine.

spring-boot-starter-web

Support for full-stack web development, including Tomcat and spring-webmvc.

spring-boot-starter-websocket

Support for WebSocket development.

spring-boot-starter-ws

Support for Spring Web Services.


In addition to the application starters, the following starters can be used to add production ready features.

Table 13.2. Spring Boot production ready starters

NameDescription

spring-boot-starter-actuator

Adds production ready features such as metrics and monitoring.

spring-boot-starter-remote-shell

Adds remote ssh shell support.


Finally, Spring Boot includes some starters that can be used if you want to exclude or swap specific technical facets.

Table 13.3. Spring Boot technical starters

NameDescription

spring-boot-starter-jetty

Imports the Jetty HTTP engine (to be used as an alternative to Tomcat).

spring-boot-starter-log4j

Support the Log4J logging framework.

spring-boot-starter-logging

Import Spring Boot’s default logging framework (Logback).

spring-boot-starter-tomcat

Import Spring Boot’s default HTTP engine (Tomcat).

spring-boot-starter-undertow

Imports the Undertow HTTP engine (to be used as an alternative to Tomcat).


[Tip]Tip

For a list of additional community contributed starter POMs, see the README file in the spring-boot-starters module on GitHub.