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Red Hat Training
A Red Hat training course is available for Red Hat Fuse
Deploying into Spring Boot
Building and running Spring Boot applications in standalone mode
fuse-docs-support@redhat.com
Abstract
Chapter 1. Getting Started with Spring Boot
1.1. Overview of the circuit breaker booster
The Netflix/Hystrix circuit breaker component enables distributed applications to cope with interruptions to network connectivity and temporary unavailability of backend services. The basic idea of the circuit breaker pattern is that the loss of a dependent service is detected automatically and an alternative behavior can be programmed, in case the backend service is temporarily unavailable.
The Fuse circuit breaker booster consists of two related services:
- A name service, which returns a name to greet, and
-
A greetings service, which invokes the name service to get a name and then returns the string,
Hello, NAME
.
In this demonstration, the Hystrix circuit breaker is inserted between the greetings service and the name service. If the name service becomes unavailable, the greetings service can fall back to an alternative behavior and respond to the client immediately, instead of blocking while it waits for the name service to restart.
1.2. Prerequisites
To build and run the booster demonstration, install the following prerequisites:
- A supported version of the Java Developer Kit (JDK). See the Supported Configurations page for details.
- Apache Maven 3.3.x or later. See the Maven Download page. To learn more about Maven, see Appendix A, Preparing to use Maven.
1.3. Generate the booster project
To generate the circuit breaker booster project, perform the following steps:
- Navigate to https://developers.redhat.com/launch.
- Click LAUNCH YOUR PROJECT.
- The launcher wizard prompts you to log in to your Red Hat account. Click the Log in or register button to log in.
- On the Deployment type page, click I will build and run locally.
- On the Mission page, select the Circuit Breaker mission and click Next.
- On the Runtime page, select the Fuse runtime (not the Spring Boot runtime) and click Next.
- On the Project Info page, select the 7.0.0 GA version from the Runtime Version dropdown menu. Accept the default settings for the other fields on this page.
- Click Next.
- On the Review Summary page, click Download as ZIP File to download the generated project.
- After downloading the ZIP file, use an archive utility to extract the generated project to a convenient location on your local filesystem.
1.4. Build and run the booster
To build and run the booster project, perform the following steps:
Open a shell prompt and build the project from the command line, using Maven:
cd booster-circuit-breaker-spring-boot mvn clean package
Open a new shell prompt and start the name service, as follows:
cd name-service mvn spring-boot:run -DskipTests -Dserver.port=8081
As Spring Boot starts up, you should see some output like the following:
... 2017-12-08 15:44:24.223 INFO 22758 --- [ main] o.a.camel.spring.SpringCamelContext : Total 1 routes, of which 1 are started 2017-12-08 15:44:24.227 INFO 22758 --- [ main] o.a.camel.spring.SpringCamelContext : Apache Camel 2.20.0 (CamelContext: camel-1) started in 0.776 seconds 2017-12-08 15:44:24.234 INFO 22758 --- [ main] org.jboss.fuse.boosters.cb.Application : Started Application in 4.137 seconds (JVM running for 4.744)
Open a new shell prompt and start the greetings service, as follows:
cd greetings-service mvn spring-boot:run -DskipTests
As Spring Boot starts up, you should see some output like the following:
... 2017-12-08 15:46:58.521 INFO 22887 --- [ main] o.a.c.c.s.CamelHttpTransportServlet : Initialized CamelHttpTransportServlet[name=CamelServlet, contextPath=] 2017-12-08 15:46:58.524 INFO 22887 --- [ main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http) 2017-12-08 15:46:58.536 INFO 22887 --- [ main] org.jboss.fuse.boosters.cb.Application : Started Application in 6.263 seconds (JVM running for 6.819)
The greetings service exposes a REST endpoint at the URL,
http://localhost:8080/camel/greetings
. You can invoke the REST endpoint either from a Web browser or from a shell prompt, using thecurl
command, as follows:$ curl http://localhost:8080/camel/greetings {"greetings":"Hello, Jacopo"}
- To demonstrate the circuit breaker functionality provided by Camel Hystrix, kill the backend name service by typing Ctrl-C in the window of the shell prompt where the name service is running.
Now that the name service is unavailable, the circuit breaker kicks in to prevent the greetings service from hanging when it is invoked. Invoke the greetings REST endpoint using the
curl
command, as follows:$ curl http://localhost:8080/camel/greetings {"greetings":"Hello, default fallback"}
The log in the window where the greetings service is running shows the following sequence of messages:
2017-12-08 16:38:30.483 INFO 23579 --- [-CamelHystrix-2] route2 : Try to call name Service 2017-12-08 16:38:30.488 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused) 2017-12-08 16:38:30.488 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : Retrying request 2017-12-08 16:38:30.489 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused) 2017-12-08 16:38:30.489 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : Retrying request 2017-12-08 16:38:30.489 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : I/O exception (java.net.ConnectException) caught when processing request: Connection refused (Connection refused) 2017-12-08 16:38:30.489 INFO 23579 --- [-CamelHystrix-2] o.a.c.httpclient.HttpMethodDirector : Retrying request 2017-12-08 16:38:30.495 INFO 23579 --- [-CamelHystrix-2] route2 : We are falling back!!!!
-
For more information about this example, visit the Circuit Breaker Mission page at http://localhost:8080/ (while the
greetings-service
is running). This page provides a link to the Hystrix dashboard, which monitors the state of the circuit breaker.
Chapter 2. Deployment Options
The following Spring Boot deployment options are supported in Fuse:
2.1. Standalone deployment
In standalone deployment mode, a Spring Boot application is packaged as a Jar file and runs directly inside the Java Virtual Machine (JVM). That is, the Spring Boot application can be run directly using the java
command with the -jar
option — for example:
java -jar SpringBootApplication.jar
Where Spring Boot provides the main class for the executable Jar. This approach to packaging and running the application is consistent with the microservices philosophy, where a service is packaged with the minimum set of requirements. The container is also minimal, being just the JVM itself.
The following elements are required for building a Spring Boot standalone application in Fuse:
The Fuse Bill of Materials (BOM) — defines a carefully curated set of dependencies from the Red Hat Maven repository. The BOM exploits Maven’s dependency management mechanism to define the appropriate versions of Maven dependencies.
NoteOnly dependencies defined in the Fuse BOM are supported by Red hat.
- The Spring Boot Maven Plug-In — implements the build process for a standalone Spring Boot application in Maven. This plug-in is responsible for packaging your Spring Boot application as an executable Jar file.
2.2. OpenShift deployment
In OpenShift deployment mode, a Spring Boot application is packaged as an OpenShift application and then uploaded to an OpenShift cluster, where it runs in one or more pods. This mode of deployment has the advantage of being highly scalable, exploiting the on-premises cloud provided by the OpenShift Container Platform (OCP) product.
For more details about the OpenShift mode of deployment, see the "Fuse Integration Services" guide.
The following elements are required for building a Spring Boot application for OpenShift in Fuse:
- The Fuse Bill of Materials (BOM) — only dependencies defined in the Fuse BOM are supported by Red hat.
- The Spring Boot Maven plug-in — builds the Spring Boot executable Jar file, which is an intermediate step in the process of building an application for OpenShift.
- The Fabric8 Maven plug-in — automates the entire process of building, packaging, and deploying an application to OpenShift.
Chapter 3. Building with Maven
The standard approach to developing applications for Spring Boot in Fuse is to use the Apache Maven build tool and to structure your source code as a Maven project. Fuse provides Maven quickstarts to get you started quickly and many of the Fuse buld tools are provided as Maven plug-ins. For this reason, it is highly recommended that you adopt Maven as the build tool for Spring Boot projects in Fuse.
3.1. Generating a Maven project
Fuse provides a selection of quickstarts, based on Maven archetypes, which you can use to generate an initial Maven project for a Spring Boot application. To save you having to remember the location information and versions for various Maven archetypes, Fuse provides tooling to help you generate Maven projects for standalone Spring Boot projects.
3.1.1. Project generator at launch.openshift.io
The quickest way to get started with Spring Boot standalone in Fuse is to navigate to launch.openshift.io and follow the instructions for the Spring Boot standalone runtime, to generate a new Maven project. After following the on-screen instructions, you will be prompted to download an archive file, which contains a complete Maven project that you can build and run locally.
3.1.2. Fuse tooling wizard in Developer Studio
Alternatively, you can download and install Red Hat JBoss Developer Studio (which includes Fuse Tooling). Using the Fuse New Integration Project wizard, you can generate a new Spring Boot standalone project and continue to develop inside the Eclipse-based IDE.
3.2. Depend on the BOM for Spring Boot
After creating and building your first Spring Boot project, you will soon want to add more components. But how do you know which versions of the Maven dependencies to add to your project? The simplest (and recommended) approach is to use the relevant Bill of Materials (BOM) file, which automatically defines all of the version dependencies for you.
3.2.1. 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 --> <bom.version>7.0.0.fuse-000027-redhat-1</bom.version> <spring-boot.version>1.5.13.RELEASE</spring-boot.version> <maven-compiler-plugin.version>3.3</maven-compiler-plugin.version> <maven-surefire-plugin.version>2.18.1</maven-surefire-plugin.version> </properties> <dependencyManagement> <dependencies> <dependency> <groupId>org.jboss.redhat-fuse</groupId> <artifactId>fuse-springboot-bom</artifactId> <version>${bom.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> ... </project>
The org.jboss.redhat-fuse
BOM is new in Fuse 7.0 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-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.
3.2.2. Spring Boot Maven plugin
The Spring Boot Maven plugin is provided by Spring Boot and it is a developer utility for building and running a Spring Boot project:
-
Building — create an executable Jar package for your Spring Boot application by entering the command
mvn package
in the project directory. The output of the build is placed in thetarget/
subdirectory of your Maven project. -
Running — for convenience, you can run the newly-built application with the command,
mvn spring-boot:start
.
To incorporate the Spring Boot Maven plugin into your project POM file, add the plugin configuration to the project/build/plugins
section of your pom.xml
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 --> <bom.version>7.0.0.fuse-000027-redhat-1</bom.version> </properties> ... <build> <plugins> <plugin> <groupId>org.jboss.redhat-fuse</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>${bom.version}</version> <executions> <execution> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> ... </project>
Chapter 4. Apache Camel in Spring Boot
4.1. Introduction to Camel Spring Boot
The Camel Spring Boot component provides auto configuration for Apache Camel. Auto-configuration of the Camel context auto-detects Camel routes available in the Spring context and registers the key Camel utilities such as producer template, consumer template, and the type converter as beans.
Every Camel Spring Boot application should use dependencyManagement
with productized versions, see quickstart pom. Versions that are tagged later can be omitted to not override the versions from BOM.
<project> ... <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <!-- configure the versions you want to use here --> <bom.version>7.0.0.fuse-000027-redhat-1</bom.version> ... </properties> <dependencyManagement> <dependencies> <dependency> <groupId>org.jboss.redhat-fuse</groupId> <artifactId>fuse-springboot-bom</artifactId> <version>${bom.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> ... </project>
camel-spring-boot
jar comes with the spring.factories
file which allows you to add that dependency into your classpath and hence Spring Boot will automatically auto-configure Camel.
4.2. Introduction to Camel Spring Boot Starter
Apache Camel includes a Spring Boot starter module that allows you to develop Spring Boot applications using starters.
For more details, see sample application in the source code.
To use the starter, add the following snippet to your Spring Boot pom.xml
file:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-boot-starter</artifactId> </dependency>
The starter allows you to add classes with your Camel routes, as shown in the snippet below. Once these routes are added to the class path the routes are started automatically.
package com.example; import org.apache.camel.builder.RouteBuilder; import org.springframework.stereotype.Component; @Component public class MyRoute extends RouteBuilder { @Override public void configure() throws Exception { from("timer:foo").to("log:bar"); } }
You can customize the Camel application in the application.properties
or application.yml
file.
Camel Spring Boot now supports referring to bean by the id name in the configuration files (application.properties or yaml file) when you configure any of the Camel starter components. In the src/main/resources/application.properties
(or yaml) file you can now easily configure the options on the Camel that refers to other beans by refering to the beans ID name. For example, the xslt component can refer to a custom bean using the bean ID as follows:
Refer to a custom bean by the id myExtensionFactory as follows:
camel.component.xslt.saxon-extension-functions=myExtensionFactory
Which you can then create using Spring Boot @Bean annotation as follows:
@Bean(name = "myExtensionFactory") public ExtensionFunctionDefinition myExtensionFactory() { }
Or, in case of a Jackson ObjectMapper in the camel-jackson
data-format:
camel.dataformat.json-jackson.object-mapper=myJacksonMapper
4.3. Auto-configured Camel context
Camel auto-configuration provides a CamelContext
instance and creates a SpringCamelContext
. It also initializes and performs shutdown of that context. This Camel context is registered in the Spring application context under camelContext
bean name and you can access it like other Spring bean.
For example, you can access the camelContext
as shown below:
@Configuration public class MyAppConfig { @Autowired CamelContext camelContext; @Bean MyService myService() { return new DefaultMyService(camelContext); } }
4.4. Auto-detecting Camel routes
Camel auto configuration collects all the RouteBuilder
instances from the Spring context and automatically injects them into the CamelContext
. It simplifies the process of creating new Camel route with the Spring Boot starter. You can create the routes by adding the @Component
annotated class to your classpath.
@Component public class MyRouter extends RouteBuilder { @Override public void configure() throws Exception { from("jms:invoices").to("file:/invoices"); } }
To create a new route RouteBuilder
bean in your @Configuration
class, see below:
@Configuration public class MyRouterConfiguration { @Bean RoutesBuilder myRouter() { return new RouteBuilder() { @Override public void configure() throws Exception { from("jms:invoices").to("file:/invoices"); } }; } }
4.5. Camel properties
Spring Boot auto configuration automatically connects to Spring Boot external configuration such as properties placeholders, OS environment variables, or system properties with Camel properties support.
These properties are defined in application.properties
file:
route.from = jms:invoices
Use as system property
java -Droute.to=jms:processed.invoices -jar mySpringApp.jar
Use as placeholders in Camel route:
@Component public class MyRouter extends RouteBuilder { @Override public void configure() throws Exception { from("{{route.from}}").to("{{route.to}}"); } }
4.6. Custom Camel context configuration
To perform operations on CamelContext
bean created by Camel auto configuration, you need to register CamelContextConfiguration
instance in your Spring context as shown below:
@Configuration public class MyAppConfig { ... @Bean CamelContextConfiguration contextConfiguration() { return new CamelContextConfiguration() { @Override void beforeApplicationStart(CamelContext context) { // your custom configuration goes here } }; } }
The method CamelContextConfiguration
and beforeApplicationStart(CamelContext)
will be called before the Spring context is started, so the CamelContext
instance passed to this callback is fully auto-configured. You can add many instances of CamelContextConfiguration
into your Spring context and all of them will be executed.
4.7. Disabling JMX
To disable JMX of the auto-configured CamelContext
use camel.springboot.jmxEnabled
property as JMX is enabled by default.
For example, you could add the following property to your application.properties
file:
camel.springboot.jmxEnabled = false
4.8. Auto-configured consumer and producer templates
Camel auto configuration provides pre-configured ConsumerTemplate
and ProducerTemplate
instances. You can inject them into your Spring-managed beans:
@Component public class InvoiceProcessor { @Autowired private ProducerTemplate producerTemplate; @Autowired private ConsumerTemplate consumerTemplate; public void processNextInvoice() { Invoice invoice = consumerTemplate.receiveBody("jms:invoices", Invoice.class); ... producerTemplate.sendBody("netty-http:http://invoicing.com/received/" + invoice.id()); } }
By default consumer templates and producer templates come with the endpoint cache sizes set to 1000. You can change those values using the following Spring properties:
camel.springboot.consumerTemplateCacheSize = 100 camel.springboot.producerTemplateCacheSize = 200
4.9. Auto-configured TypeConverter
Camel auto configuration registers a TypeConverter
instance named typeConverter
in the Spring context.
@Component public class InvoiceProcessor { @Autowired private TypeConverter typeConverter; public long parseInvoiceValue(Invoice invoice) { String invoiceValue = invoice.grossValue(); return typeConverter.convertTo(Long.class, invoiceValue); } }
4.10. Spring type conversion API bridge
Spring consist of type conversion API. Spring API is similar to the Camel type converter API. Due to the similarities between the two APIs Camel Spring Boot automatically registers a bridge converter (SpringTypeConverter
) that delegates to the Spring conversion API. That means that out-of-the-box Camel will treat Spring Converters similar to Camel.
This allows you to access both Camel and Spring converters using the Camel TypeConverter
API, as shown below:
@Component public class InvoiceProcessor { @Autowired private TypeConverter typeConverter; public UUID parseInvoiceId(Invoice invoice) { // Using Spring's StringToUUIDConverter UUID id = invoice.typeConverter.convertTo(UUID.class, invoice.getId()); } }
Here, Spring Boot delegates conversion to the Spring’s ConversionService
instances available in the application context. If no ConversionService
instance is available, Camel Spring Boot auto configuration creates an instance of ConversionService
.
4.11. Disabling type conversions features
To disable registering type conversion features of Camel Spring Boot such as TypeConverter
instance or Spring bridge, set the camel.springboot.typeConversion
property to false
as shown below:
camel.springboot.typeConversion = false
4.12. Adding XML routes
By default, you can put Camel XML routes in the classpath under the directory camel, which camel-spring-boot
will auto detect and include. From Camel version 2.17 onwards you can configure the directory name or disable this feature using the configuration option, as shown below:
// turn off camel.springboot.xmlRoutes = false // scan in the com/foo/routes classpath camel.springboot.xmlRoutes = classpath:com/foo/routes/*.xml
The XML files should be Camel XML routes and not CamelContext
such as:
<routes xmlns="http://camel.apache.org/schema/spring"> <route id="test"> <from uri="timer://trigger"/> <transform> <simple>ref:myBean</simple> </transform> <to uri="log:out"/> </route> </routes>
When using Spring XML files with <camelContext>, you can configure Camel in the Spring XML file as well as in the application.properties file. For example, to set a name on Camel and turn On the stream caching, add:
camel.springboot.name = MyCamel camel.springboot.stream-caching-enabled=true
4.13. Adding XML Rest-DSL
By default, you can put Camel Rest-DSL XML routes in the classpath under the directory camel-rest
, which camel-spring-boot
will auto detect and include. You can configure the directory name or disable this feature using the configuration option, as shown below:
// turn off camel.springboot.xmlRests = false // scan in the com/foo/routes classpath camel.springboot.xmlRests = classpath:com/foo/rests/*.xml
The Rest-DSL XML files should be Camel XML rests and not CamelContext
such as:
<rests xmlns="http://camel.apache.org/schema/spring"> <rest> <post uri="/persons"> <to uri="direct:postPersons"/> </post> <get uri="/persons"> <to uri="direct:getPersons"/> </get> <get uri="/persons/{personId}"> <to uri="direct:getPersionId"/> </get> <put uri="/persons/{personId}"> <to uri="direct:putPersionId"/> </put> <delete uri="/persons/{personId}"> <to uri="direct:deletePersionId"/> </delete> </rest> </rests>
4.14. Testing with Camel Spring Boot
In case on Camel running on Spring Boot, Spring Boot automatically embeds Camel and all its routes, which are annotated with @Component
. When testing with Spring boot you use @SpringBootTest
instead of @ContextConfiguration
to specify which configuration class to use.
When you have multiple Camel routes in different RouteBuilder classes, Camel Spring Boot will include all these routes. Hence, when you wish to test routes from only one RouteBuilder class you can use the following patterns to include or exclude which RouteBuilders to enable:
- java-routes-include-pattern: Used for including RouteBuilder classes that match the pattern.
- java-routes-exclude-pattern: Used for excluding RouteBuilder classes that match the pattern. Exclude takes precedence over include.
You can specify these patterns in your unit test classes as properties to @SpringBootTest
annonation, as shown below:
@RunWith(CamelSpringBootRunner.class) @SpringBootTest(classes = {MyApplication.class); properties = {"camel.springboot.java-routes-include-pattern=**/Foo*"}) public class FooTest {
In the FooTest
class, the include pattern is **/Foo*
, which represents an Ant style pattern. Here, the pattern starts with double asterisk, which matches with any leading package name. /Foo*
means the class name must start with Foo, for example, FooRoute. You can run a test using following maven command:
mvn test -Dtest=FooTest
4.15. See Also
4.16. Using Spring Boot, Apache Camel and external messaging brokers
4.16.1. Using an external messaging broker.
Fuse uses external messaging brokers. See Supported Configurations for more information about the supported broker, client and Camel component combinations.
The Camel component must be connected to the JMS connection-factory. The example below shows how to connect the camel-amqp
component to a JMS connection-factory.
import org.apache.activemq.jms.pool.PooledConnectionFactory; import org.apache.camel.component.amqp.AMQPComponent; import org.apache.qpid.jms.JmsConnectionFactory; ... AMQPComponent amqpComponent(AMQPConfiguration config) { JmsConnectionFactory qpid = new JmsConnectionFactory(config.getUsername(), config.getPassword(), "amqp://"+ config.getHost() + ":" + config.getPort()); qpid.setTopicPrefix("topic://"); PooledConnectionFactory factory = new PooledConnectionFactory(); factory.setConnectionFactory(qpid); AMQPComponent amqpcomp = new AMQPComponent(factory);
Appendix A. Preparing to use Maven
A.1. Overview
This section gives a brief overview of how to prepare Maven for building Red Hat JBoss Fuse projects and introduces the concept of Maven coordinates, which are used to locate Maven artifacts.
A.2. Prerequisites
In order to build a project using Maven, you must have the following prerequisites:
- Maven installation — Maven is a free, open source build tool from Apache. You can download the latest version from the Maven download page.
Network connection — whilst performing a build, Maven dynamically searches external repositories and downloads the required artifacts on the fly. By default, Maven looks for repositories that are accessed over the Internet. You can change this behavior so that Maven will prefer searching repositories that are on a local network.
NoteMaven can run in an offline mode. In offline mode Maven only looks for artifacts in its local repository.
A.3. Adding the Red Hat Maven repositories
In order to access artifacts from the Red Hat Maven repositories, you need to add them to Maven’s settings.xml
file. Maven looks for your settings.xml
file in the .m2
directory of the user’s home directory. If there is not a user specified settings.xml
file, Maven will use the system-level settings.xml
file at M2_HOME/conf/settings.xml
.
To add the Red Hat repositories to Maven’s list of repositories, you can either create a new .m2/settings.xml
file or modify the system-level settings. In the settings.xml
file, add repository
elements for the Red Hat repositories as shown in Adding the Red Hat JBoss Fuse Repositories to Maven.
Adding the Red Hat JBoss Fuse Repositories to Maven
<?xml version="1.0"?> <settings> <profiles> <profile> <id>extra-repos</id> <activation> <activeByDefault>true</activeByDefault> </activation> <repositories> <repository> <id>redhat-ga-repository</id> <url>https://maven.repository.redhat.com/ga</url> <releases> <enabled>true</enabled> </releases> <snapshots> <enabled>false</enabled> </snapshots> </repository> <repository> <id>redhat-ea-repository</id> <url>https://maven.repository.redhat.com/earlyaccess/all</url> <releases> <enabled>true</enabled> </releases> <snapshots> <enabled>false</enabled> </snapshots> </repository> <repository> <id>jboss-public</id> <name>JBoss Public Repository Group</name> <url>https://repository.jboss.org/nexus/content/groups/public/</url> </repository> </repositories> <pluginRepositories> <pluginRepository> <id>redhat-ga-repository</id> <url>https://maven.repository.redhat.com/ga</url> <releases> <enabled>true</enabled> </releases> <snapshots> <enabled>false</enabled> </snapshots> </pluginRepository> <pluginRepository> <id>redhat-ea-repository</id> <url>https://maven.repository.redhat.com/earlyaccess/all</url> <releases> <enabled>true</enabled> </releases> <snapshots> <enabled>false</enabled> </snapshots> </pluginRepository> <pluginRepository> <id>jboss-public</id> <name>JBoss Public Repository Group</name> <url>https://repository.jboss.org/nexus/content/groups/public</url> </pluginRepository> </pluginRepositories> </profile> </profiles> <activeProfiles> <activeProfile>extra-repos</activeProfile> </activeProfiles> </settings>
A.4. Artifacts
The basic building block in the Maven build system is an artifact. The output of an artifact, after performing a Maven build, is typically an archive, such as a JAR or a WAR.
A.5. Maven coordinates
A key aspect of Maven functionality is the ability to locate artifacts and manage the dependencies between them. Maven defines the location of an artifact using the system of Maven coordinates, which uniquely define the location of a particular artifact. A basic coordinate tuple has the form, {groupId, artifactId, version}
. Sometimes Maven augments the basic set of coordinates with the additional coordinates, packaging and classifier. A tuple can be written with the basic coordinates, or with the additional packaging coordinate, or with the addition of both the packaging and classifier coordinates, as follows:
groupdId:artifactId:version groupdId:artifactId:packaging:version groupdId:artifactId:packaging:classifier:version
Each coordinate can be explained as follows:
- groupdId
-
Defines a scope for the name of the artifact. You would typically use all or part of a package name as a group ID — for example,
org.fusesource.example
. - artifactId
- Defines the artifact name (relative to the group ID).
- version
-
Specifies the artifact’s version. A version number can have up to four parts:
n.n.n.n
, where the last part of the version number can contain non-numeric characters (for example, the last part of1.0-SNAPSHOT
is the alphanumeric substring,0-SNAPSHOT
). - packaging
-
Defines the packaged entity that is produced when you build the project. For OSGi projects, the packaging is
bundle
. The default value isjar
. - classifier
- Enables you to distinguish between artifacts that were built from the same POM, but have different content.
The group ID, artifact ID, packaging, and version are defined by the corresponding elements in an artifact’s POM file. For example:
<project ... > ... <groupId>org.fusesource.example</groupId> <artifactId>bundle-demo</artifactId> <packaging>bundle</packaging> <version>1.0-SNAPSHOT</version> ... </project>
For example, to define a dependency on the preceding artifact, you could add the following dependency
element to a POM:
<project ... > ... <dependencies> <dependency> <groupId>org.fusesource.example</groupId> <artifactId>bundle-demo</artifactId> <version>1.0-SNAPSHOT</version> </dependency> </dependencies> ... </project>
It is not necessary to specify the bundle
package type in the preceding dependency, because a bundle is just a particular kind of JAR file and jar
is the default Maven package type. If you do need to specify the packaging type explicitly in a dependency, however, you can use the type
element.
Appendix B. Spring Boot Maven Plug-In
B.1. Spring Boot Maven Plugin Overview
This appendix describes the Spring Boot Maven Plugin. It provides the Spring Boot support in Maven and allows you to package the executable jar or war archives and run an application in-place
.
B.2. Goals
The Spring Boot Plugin includes the following goals:
-
spring-boot:run
runs your Spring Boot application. -
spring-boot:repackage
repackages your.jar
and.war
files to be executable. -
spring-boot:start
andspring-boot:stop
both are used to manage the lifecycle of your Spring Boot application. -
spring-boot:build-info
generates build information that can be used by the Actuator.
B.3. Usage
You can find general instructions on how to use the Spring Boot Plugin at: http://docs.spring.io/spring-boot/docs/current/maven-plugin/usage.html
. Following is an example that illustrates the usage of the spring-boot-maven-plugin
plugin:
<project> <modelVersion>4.0.0</modelVersion> <groupId>io.fabric8.quickstarts</groupId> <artifactId>spring-boot-camel</artifactId> <version>1.0-SNAPSHOT</version> <name>Fabric8 :: Quickstarts :: Spring-Boot :: Camel</name> <description>Spring Boot example running a Camel route</description> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <!-- configure the versions you want to use here --> <fuse.version>7.0.0.fuse-000191-redhat-1</fuse.version> <bom.version>7.0.0.fuse-000027-redhat-1</bom.version> <fabric8.version>3.0.11.fuse-000039-redhat-1</fabric8.version> <spring-boot.version>1.5.13.RELEASE</spring-boot.version> <!-- maven plugin versions --> <fabric8.maven.plugin.version>3.5.33.fuse-000067-redhat-1</fabric8.maven.plugin.version> <maven-compiler-plugin.version>3.3</maven-compiler-plugin.version> <maven-surefire-plugin.version>2.18.1</maven-surefire-plugin.version> </properties> <dependencyManagement> <dependencies> <dependency> <groupId>org.jboss.redhat-fuse</groupId> <artifactId>fuse-springboot-bom</artifactId> <version>${bom.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- Enabling health checks --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-spring-boot-starter</artifactId> </dependency> <!-- testing --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.jboss.arquillian.junit</groupId> <artifactId>arquillian-junit-container</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>io.fabric8</groupId> <artifactId>fabric8-arquillian</artifactId> <scope>test</scope> </dependency> </dependencies> <build> <defaultGoal>spring-boot:run</defaultGoal> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>${maven-compiler-plugin.version}</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <version>${maven-surefire-plugin.version}</version> <inherited>true</inherited> <configuration> <excludes> <exclude>**/*KT.java</exclude> </excludes> </configuration> </plugin> <plugin> <groupId>org.jboss.redhat-fuse</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>${bom.version}</version> <executions> <execution> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>io.fabric8</groupId> <artifactId>fabric8-maven-plugin</artifactId> <version>${fabric8.maven.plugin.version}</version> <executions> <execution> <goals> <goal>resource</goal> <goal>build</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project>
For more information on Spring Boot Maven Plugin, refer the http://docs.spring.io/spring-boot/docs/current/maven-plugin
link.