Adding Spring Boot to our main project

We will use Java 11 to develop microservices. Therefore, we'll use the latest Spring Framework and Spring Boot project. At the time of writing, Spring Boot 2.1.0 M2 release version is available.

You can use the latest released version. Spring Boot 2.1.0 M2 snapshot uses Spring 5 (5.1.0 M2 release).

Now, let's take a look at the following steps and learn about adding Spring Boot to our main project:

1. Open the pom.xml file (available under Chapter2 | Project Files) to add Spring Boot to your sample project:

<?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   
   http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <groupId>com.packtpub.mmj</groupId>
   <artifactId>11537_chapter2</artifactId>
   <version>1.0-SNAPSHOT</version>
   <packaging>pom</packaging>

   <modules>
      <module>lib</module>
      <module>rest</module>
   </modules>

   <properties>
      <project.build.sourceEncoding>UTF-8
         </project.build.sourceEncoding>
      <maven.compiler.source>11</maven.compiler.source>
      <maven.compiler.target>11</maven.compiler.target>
      <start-class>com.packtpub.mmj.rest.RestSampleApp
      </start-class>
   </properties>
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.1.0.M2</version>
   </parent>
   <dependencyManagement>
      <dependencies>
         <dependency>
            <groupId>com.packtpub.mmj</groupId>
            <artifactId>rest</artifactId>
            <version>${project.version}</version>
         </dependency>
         <dependency>
            <groupId>com.packtpub.mmj</groupId>
            <artifactId>lib</artifactId>
            <version>${project.version}</version>
         </dependency>
      </dependencies>
   </dependencyManagement>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <executions>
               <execution>
                  <goals>
                     <goal>repackage</goal>
                  </goals>
                  <configuration>
                     <classifier>exec</classifier>
                     <mainClass>${start-class}</mainClass>
                  </configuration>
               </execution>
            </executions>
         </plugin>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
               <release>11</release>
               <source>1.11</source>
               <target>1.11</target>
               <executable>${JAVA_1_11_HOME}/bin/javac</executable>
               <showDeprecation>true</showDeprecation>
               <showWarnings>true</showWarnings>
            </configuration>
            <dependencies>
               <dependency>
                  <groupId>org.ow2.asm</groupId>
                  <artifactId>asm</artifactId>
                  <version>6.2</version> 
                  <!-- Use newer version of ASM -->
               </dependency>
            </dependencies>
         </plugin>
      </plugins>
   </build>
   <repositories>
      <repository>
         <id>spring-snapshots</id>
         <name>Spring Snapshots</name>
         <url>https://repo.spring.io/snapshot</url>
         <snapshots>
            <enabled>true</enabled>
         </snapshots>
      </repository>
      <repository>
         <id>spring-milestones</id>
         <name>Spring Milestones</name>
         <url>https://repo.spring.io/milestone</url>
         <snapshots>
            <enabled>false</enabled>
         </snapshots>
      </repository>
   </repositories>

   <pluginRepositories>
      <pluginRepository>
         <id>spring-snapshots</id>
         <name>Spring Snapshots</name>
         <url>https://repo.spring.io/snapshot</url>
         <snapshots>
            <enabled>true</enabled>
         </snapshots>
      </pluginRepository>
      <pluginRepository>
         <id>spring-milestones</id>
         <name>Spring Milestones</name>
         <url>https://repo.spring.io/milestone</url>
         <snapshots>
            <enabled>false</enabled>
         </snapshots>
      </pluginRepository>
   </pluginRepositories>
</project>

You can observe that we have defined our two modules, lib and rest, in the pom.xml parent project.

1. If you are adding these dependencies for the first time, project build would download these dependencies.
2. Similarly, to resolve the project problems, right-click on the NetBeans project, 6392_chapter2, and opt for the Resolve Project Problems.... It will open the dialog shown as follows. Click on the Resolve... button to resolve the issues.
3. If you are using Maven behind the proxy, then update the proxies in settings.xml in the Maven home directory. If you are using the Maven bundled with NetBeans, then use <NetBeans Installation Directory>\java\maven\conf\settings.xml. You may need to restart the NetBeans IDE.

The preceding steps will download all the required dependencies from a remote Maven repository if the declared dependencies and transitive dependencies are not available in a local Maven repository. If you are downloading the dependencies for the first time, then it may take a bit of time, depending on your internet speed.