Moves away from Class.forName() to order.

spring-cloud-context/src/main/java/org/springframework/cloud/bootstrap/BootstrapImportSelector.java

@@ -16,18 +16,25 @@
 
 package org.springframework.cloud.bootstrap;
 
+import java.io.IOException;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.AnnotatedElement;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Collectors;
+import java.util.Map;
 
 import org.springframework.context.EnvironmentAware;
 import org.springframework.context.annotation.DeferredImportSelector;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
+import org.springframework.core.annotation.Order;
 import org.springframework.core.env.Environment;
 import org.springframework.core.io.support.SpringFactoriesLoader;
+import org.springframework.core.style.ToStringCreator;
 import org.springframework.core.type.AnnotationMetadata;
-import org.springframework.util.ClassUtils;
+import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
+import org.springframework.core.type.classreading.MetadataReader;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
 import org.springframework.util.StringUtils;
 
 /**
@@ -41,13 +48,15 @@ public class BootstrapImportSelector implements EnvironmentAware, DeferredImport
 
 	private Environment environment;
 
+	private MetadataReaderFactory metadataReaderFactory = new CachingMetadataReaderFactory();
+
 	@Override
 	public void setEnvironment(Environment environment) {
 		this.environment = environment;
 	}
 
 	@Override
-	public String[] selectImports(AnnotationMetadata metadata) {
+	public String[] selectImports(AnnotationMetadata annotationMetadata) {
 		ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
 		// Use names and ensure unique to protect against duplicates
 		List<String> names = new ArrayList<>(SpringFactoriesLoader
@@ -55,24 +64,75 @@ public class BootstrapImportSelector implements EnvironmentAware, DeferredImport
 		names.addAll(Arrays.asList(StringUtils.commaDelimitedListToStringArray(
 				environment.getProperty("spring.cloud.bootstrap.sources", ""))));
 
-		List<Class<?>> sources = new ArrayList<>();
+		List<OrderedAnnotatedElement> elements = new ArrayList<>();
 		for (String name : names) {
-			Class<?> cls = ClassUtils.resolveClassName(name, null);
 			try {
-				cls.getDeclaredAnnotations();
-			}
-			catch (Exception e) {
+				elements.add(new OrderedAnnotatedElement(metadataReaderFactory, name));
+			} catch (IOException e) {
 				continue;
 			}
-			sources.add(cls);
 		}
-		AnnotationAwareOrderComparator.sort(sources);
+		AnnotationAwareOrderComparator.sort(elements);
 
-		List<String> classNames = sources.stream()
-				.map(Class::getName)
-				.collect(Collectors.toList());
+		String[] classNames = elements.stream()
+				.map(e -> e.name)
+				.toArray(String[]::new);
 
+		return classNames;
+	}
 
-		return classNames.toArray(new String[0]);
+	class OrderedAnnotatedElement implements AnnotatedElement {
+
+		private final String name;
+		private Order order = null;
+		private Integer value;
+
+		public OrderedAnnotatedElement(MetadataReaderFactory metadataReaderFactory, String name) throws IOException {
+			MetadataReader metadataReader = metadataReaderFactory.getMetadataReader(name);
+			AnnotationMetadata metadata = metadataReader.getAnnotationMetadata();
+			Map<String, Object> attributes = metadata.getAnnotationAttributes(Order.class.getName());
+			this.name = name;
+			if (attributes != null && attributes.containsKey("value")) {
+				value = (Integer) attributes.get("value");
+				order = new Order() {
+					@Override
+					public Class<? extends Annotation> annotationType() {
+						return Order.class;
+					}
+
+					@Override
+					public int value() {
+						return value;
+					}
+				};
+			}
+		}
+
+		@Override
+		@SuppressWarnings("unchecked")
+		public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
+			if (annotationClass == Order.class) {
+				return (T) order;
+			}
+			return null;
+		}
+
+		@Override
+		public Annotation[] getAnnotations() {
+			return new Annotation[]{order};
+		}
+
+		@Override
+		public Annotation[] getDeclaredAnnotations() {
+			return getAnnotations();
+		}
+
+		@Override
+		public String toString() {
+			return new ToStringCreator(this)
+					.append("name", name)
+					.append("value", value)
+					.toString();
+		}
 	}
 }