To get started, just upload your code through the AWS Lambda console or CLI and select the Java 11 runtime. You can also use the AWS Serverless Application Model (SAM) to deploy and manage your serverless application authored in Java. If you have existing Java 8 functions you can migrate them to the new runtime by making any required code changes to ensure compatibility with Java 11 and Amazon Linux 2. Then edit the function runtime configuration to Java 11. You can read more about the Java programming model in the AWS Lambda documentation.