To start your application using a different Spring Boot version

To start your application using a different Spring Boot version by configuring the pom.xml, follow these steps:

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Configuring pom.xml for Runtime Spring Boot Version Switching

1. Set the Spring Boot Version as a Maven Property: Define the Spring Boot version using a property in the pom.xml, allowing it to be overridden at runtime.

   <properties> <spring.boot.version>2.5.15</spring.boot.version> <!-- Default Version --> </properties>

2. Use dependencyManagement for Spring Boot Dependencies: Import the Spring Boot BOM (Bill of Materials) using the defined version property. This ensures all Spring Boot dependencies use the specified version.

   <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring.boot.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>

3. Add Spring Boot Dependencies as Usual: Use Spring Boot dependencies without specifying their version, as the BOM ensures they inherit the correct version.

   <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> </dependencies>

4. Override the Version at Build or Runtime: You can specify a different Spring Boot version by overriding the property when building or running the application.

   Build Time:

   mvn clean package -Dspring.boot.version=2.3.12.RELEASE

   Runtime (with Executable JAR): If you have already built the application but want to run it with a different version:

   • Ensure the dependencies are not embedded in the JAR (spring-boot-maven-plugin configuration).
   • Provide the required version in the classpath at runtime.

   java -Dspring.boot.version=2.3.12.RELEASE -jar target/your-app.jar

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Example pom.xml for Dynamic Version Switching

Here is a complete example of a pom.xml that supports switching Spring Boot versions:

<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.example</groupId> <artifactId>spring-boot-version-switch</artifactId> <version>1.0.0</version> <packaging>jar</packaging> <properties> <!-- Define the Spring Boot version property --> <spring.boot.version>2.5.15</spring.boot.version> <java.version>1.8</java.version> </properties> <dependencyManagement> <dependencies> <!-- Import Spring Boot dependencies dynamically --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${spring.boot.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <!-- Add your Spring Boot dependencies without specifying versions --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <executable>true</executable> </configuration> </plugin> </plugins> </build> </project>

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How to Test Different Versions

• Default Version:

  mvn clean package

• Different Version (e.g., 2.3.12.RELEASE):

  mvn clean package -Dspring.boot.version=2.3.12.RELEASE

The dependencies will automatically switch to the specified version