Package and Run Spring Boot: mvn package + java -jar

To package and run a Spring Boot app with Maven, you follow a two-step process. First, you build the application by running mvn clean package. The clean part is important — it wipes out your target directory to make sure you're starting fresh without any old compiled code hanging around. Then package compiles your source, runs your tests, and creates the executable Boot archive in the target directory. The JAR file is named based on your pom.xml — it's your artifactId followed by your version, like order-service-1.0.0.jar. This JAR has everything bundled in — your code, all dependencies, and the embedded Tomcat server. It's completely self-contained. Second step, you run the JAR with java -jar target/order-service-1.0.0.jar. Notice you're using the standard java command here, not Maven. That's a key point — once you have the JAR, you can run it on any machine with Java installed, even if Maven isn't there. This makes deployment really simple. A common mistake freshers make is forgetting the clean phase and wondering why deleted code is still executing. Another one is getting the filename wrong because they don't realize it includes the version number from pom.xml. You can also pass configuration at runtime without rebuilding. For example, java -jar myapp.jar --server.port=9090 changes the port. Or you can set JVM memory with java -Xmx512m -jar myapp.jar to limit heap size. This flexibility is huge for production — you build once, then deploy the same JAR to dev, staging, and production with different configurations. For running in the background on a server, you'd typically use nohup java -jar myapp.jar and redirect output to a log file, or better yet, use a proper process manager like systemd.