package example; import java.util.function.Function; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; @SpringBootApplication public class FunctionConfiguration { /* * You need this main method or explicit example.FunctionConfiguration * in the POM to ensure boot plug-in makes the correct entry */ public static void main(String[] args) { SpringApplication.run(FunctionConfiguration.class, args); } @Bean public Function uppercase() { return value -> value.toUpperCase(); } }