Fix annotated commands registration in GraalVM native image

Before this commit, annotated commands where fetched by scanning the
classpath for component types at runtime, which native image can't do.

This commit fixes that by looking for candidate components as beans
from the application context.

Resolves #1229

Author: fmbenhassine

spring-shell-core-autoconfigure/src/main/java/org/springframework/shell/core/autoconfigure/CommandRegistryAutoConfiguration.java

@@ -22,22 +22,17 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
-import org.springframework.aop.support.AopUtils;
-import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
 import org.springframework.core.MethodIntrospector;
 import org.springframework.core.annotation.AnnotatedElementUtils;
-import org.springframework.shell.core.ShellConfigurationException;
 import org.springframework.shell.core.command.Command;
 import org.springframework.shell.core.command.CommandRegistry;
 import org.springframework.shell.core.command.annotation.support.CommandFactoryBean;
 import org.springframework.shell.core.utils.Utils;
-import org.springframework.util.ClassUtils;
+import org.springframework.stereotype.Component;
 import org.springframework.util.ReflectionUtils;
 
 @AutoConfiguration
@@ -61,33 +56,21 @@ private void registerProgrammaticCommands(ApplicationContext applicationContext,
 	}
 
 	private void registerAnnotatedCommands(ApplicationContext applicationContext, CommandRegistry commandRegistry) {
-		Map<String, Object> springBootApps = applicationContext.getBeansWithAnnotation(SpringBootApplication.class);
-		Class<?> mainClass = AopUtils.getTargetClass(springBootApps.values().iterator().next());
-		String mainPackage = ClassUtils.getPackageName(mainClass);
-		ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(true);
-		Set<BeanDefinition> candidateComponents = scanner.findCandidateComponents(mainPackage);
-		for (BeanDefinition candidateComponent : candidateComponents) {
-			String className = candidateComponent.getBeanClassName();
-			if (className == null) {
-				log.warn(String.format("Skipping candidate component %s with null class name", candidateComponent));
+		Map<String, Object> components = applicationContext.getBeansWithAnnotation(Component.class);
+		for (Object candidateComponent : components.values()) {
+			Class<?> type = candidateComponent.getClass();
+			String className = type.getName();
+			if (className.startsWith("org.springframework.boot")) {
 				continue;
 			}
-			else {
-				log.debug("Registering commands from component: " + className);
-			}
-			try {
-				Class<?> cls = ClassUtils.forName(className, applicationContext.getClassLoader());
-				ReflectionUtils.MethodFilter filter = method -> AnnotatedElementUtils.hasAnnotation(method,
-						org.springframework.shell.core.command.annotation.Command.class);
-				Set<Method> methods = MethodIntrospector.selectMethods(cls, filter);
-				for (Method method : methods) {
-					CommandFactoryBean factoryBean = new CommandFactoryBean(method);
-					factoryBean.setApplicationContext(applicationContext);
-					commandRegistry.registerCommand(factoryBean.getObject());
-				}
-			}
-			catch (ClassNotFoundException e) {
-				throw new ShellConfigurationException("Unable to configure commands from class " + className, e);
+			log.debug("Registering commands from component: " + className);
+			ReflectionUtils.MethodFilter filter = method -> AnnotatedElementUtils.hasAnnotation(method,
+					org.springframework.shell.core.command.annotation.Command.class);
+			Set<Method> methods = MethodIntrospector.selectMethods(type, filter);
+			for (Method method : methods) {
+				CommandFactoryBean factoryBean = new CommandFactoryBean(method);
+				factoryBean.setApplicationContext(applicationContext);
+				commandRegistry.registerCommand(factoryBean.getObject());
 			}
 		}
 	}

spring-shell-docs/modules/ROOT/pages/building.adoc

@@ -160,7 +160,3 @@ under `target` directory.
 If everything went well this binary can be run as is instead of executing
 boot application jar via jvm.
 
-IMPORTANT: As of v4.0.0, the declarative annotation-based commands registration is not supported
-for native compilation, only the programmatic approach of defining commands is supported at
-this time.
-