Chapter 4. Migrate Maven Projects
To simplify migration of Maven projects, Fuse provides several Maven Bill of Materials (BOM) files. A common parent BOM file defines mutual dependencies. There is also a dedicated BOM file for each container that Fuse runs in:
- Apache Karaf
- JBoss EAP
- Spring Boot
Each BOM file is a set of Maven dependency versions that work well together. This removes the need to define the version individually for each Maven artifact.
You can find these BOM files here: https://github.com/jboss-fuse/redhat-fuse. The following sections provide details for using the BOM files to migrate your Maven projects.
4.1. BOM file for Apache Karaf
The purpose of a Maven Bill of Materials (BOM) file is to provide a curated set of Maven dependency versions that work well together, saving you from having to define versions individually for every Maven artifact.
The Fuse BOM for Apache Karaf offers the following advantages:
- Defines versions for Maven dependencies, so that you do not need to specify the version when you add a dependency to your POM.
- Defines a set of curated dependencies that are fully tested and supported for a specific version of Fuse.
- Simplifies upgrades of Fuse.
Only the set of dependencies defined by a Fuse BOM are supported by Red Hat.
To incorporate a Maven BOM file into your Maven project, specify a dependencyManagement element in your project’s pom.xml file (or, possibly, in a parent POM file), as shown in the following example:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project ...>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!-- configure the versions you want to use here -->
<fuse.version>7.3.0.fuse-730058-redhat-00001</fuse.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.jboss.redhat-fuse</groupId>
<artifactId>fuse-karaf-bom</artifactId>
<version>${fuse.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
...
</project>
The org.jboss.redhat-fuse BOM is new in Fuse 7 and has been designed to simplify BOM versioning. The Fuse quickstarts and Maven archetypes still use the old style of BOM, however, as they have not yet been refactored to use the new one. Both BOMs are correct and you can use either one in your Maven projects. In an upcoming Fuse release, the quickstarts and Maven archetypes will be refactored to use the new BOM.
After specifying the BOM using the dependency management mechanism, it becomes possible to add Maven dependencies to your POM without specifying the version of the artifact. For example, to add a dependency for the camel-velocity component, you would add the following XML fragment to the dependencies element in your POM:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-velocity</artifactId> </dependency>
Note how the version element is omitted from this dependency definition.
4.2. BOM file for JBoss EAP
The purpose of a Maven Bill of Materials (BOM) file is to provide a curated set of Maven dependency versions that work well together, saving you from having to define versions individually for every Maven artifact.
The Fuse BOM for JBoss EAP offers the following advantages:
- Defines versions for Maven dependencies, so that you do not need to specify the version when you add a dependency to your POM.
- Defines a set of curated dependencies that are fully tested and supported for a specific version of Fuse.
- Simplifies upgrades of Fuse.
Only the set of dependencies defined by a Fuse BOM are supported by Red Hat.
To incorporate a BOM file into your Maven project, specify a dependencyManagement element in your project’s pom.xml file (or, possibly, in a parent POM file), as shown in the following example:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project ...>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!-- configure the versions you want to use here -->
<fuse.version>7.3.0.fuse-730058-redhat-00001</fuse.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.jboss.redhat-fuse</groupId>
<artifactId>fuse-eap-bom</artifactId>
<version>${fuse.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
...
</project>
After specifying the BOM using the dependency management mechanism, it becomes possible to add Maven dependencies to your POM without specifying the version of the artifact. For example, to add a dependency for the camel-velocity component, you would add the following XML fragment to the dependencies element in your POM:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-velocity</artifactId> <scope>provided</scope> </dependency>
Note how the version element is omitted from this dependency definition.
4.3. BOM file for Spring Boot
The purpose of a Maven Bill of Materials (BOM) file is to provide a curated set of Maven dependency versions that work well together, saving you from having to define versions individually for every Maven artifact.
The Fuse BOM for Spring Boot offers the following advantages:
- Defines versions for Maven dependencies, so that you do not need to specify the version when you add a dependency to your POM.
- Defines a set of curated dependencies that are fully tested and supported for a specific version of Fuse.
- Simplifies upgrades of Fuse.
Only the set of dependencies defined by a Fuse BOM are supported by Red Hat.
To incorporate a BOM file into your Maven project, specify a dependencyManagement element in your project’s pom.xml file (or, possibly, in a parent POM file), as shown in the following example:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project ...>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<!-- configure the versions you want to use here -->
<fuse.version>7.3.0.fuse-730058-redhat-00001</fuse.version>
<spring-boot.version>1.5.17.RELEASE</spring-boot.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.jboss.redhat-fuse</groupId>
<artifactId>fuse-springboot-bom</artifactId>
<version>${fuse.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
...
</project>
After specifying the BOM using the dependency management mechanism, it becomes possible to add Maven dependencies to your POM without specifying the version of the artifact. For example, to add a dependency for the camel-hystrix component, you would add the following XML fragment to the dependencies element in your POM:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-hystrix-starter</artifactId> </dependency>
Note how the Camel artifact ID is specified with the -starter suffix — that is, you specify the Camel Hystrix component as camel-hystrix-starter, not as camel-hystrix. The Camel starter components are packaged in a way that is optimized for the Spring Boot environment.
