You can either run a Spring Boot application or build a jar from it. You can do both with either Gradle or Maven

Gradle

The command for running a Spring Boot app with Gradle is:

./gradlew bootRun

The command for building a jar from a Spring Boot application is:

./gradlew build

The command for running a jar is:

java -jar build/libs/<jar_filename>.jar

In the above command for running the jar, the jar filename refers to the name of the jar file including its version number but not including its .jar file extension and not including its full path.

Maven

The command for running a Spring Boot app with Maven is:

./mvnw spring-boot:run

The command for building a jar from a Spring Boot application with Maven is:

./mvnw clean package

The command for running a jar is:

java -jar build/libs/<jar_filename>.jar

When you run a Maven build, it runs your tests before producing the final output. If any tests fail, the build will fail.

Jar Locations in Gradle and Maven

When you build a jar with Gradle, the JAR file is stored in /build/libs/ while when you build the JAR with Maven, it is stored in /target

P.S. The app is much faster when you run the JAR than when you do a regular run.