Update ClassNameGenerator to work with a ClassName target

This commit updates ClassNameGenerator so that it uses a ClassName for
its default target. This makes sure that a target that has been
generated can be used.

See gh-29027

spring-core/src/main/java/org/springframework/aot/generate/ClassNameGenerator.java

@@ -27,8 +27,8 @@ import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
 /**
- * Generate unique class names based on a target {@link Class} and a feature
- * name.
+ * Generate unique class names based on a target {@link ClassName} and a
+ * feature name.
  *
  * <p>This class is stateful, so the same instance should be used for all name
  * generation.
@@ -43,7 +43,7 @@ public final class ClassNameGenerator {
 
 	private static final String AOT_FEATURE = "Aot";
 
-	private final Class<?> defaultTarget;
+	private final ClassName defaultTarget;
 
 	private final String featureNamePrefix;
 
@@ -55,7 +55,7 @@ public final class ClassNameGenerator {
 	 * feature name prefix.
 	 * @param defaultTarget the default target class to use
 	 */
-	public ClassNameGenerator(Class<?> defaultTarget) {
+	public ClassNameGenerator(ClassName defaultTarget) {
 		this(defaultTarget, "");
 	}
 
@@ -65,11 +65,11 @@ public final class ClassNameGenerator {
 	 * @param defaultTarget the default target class to use
 	 * @param featureNamePrefix the prefix to use to qualify feature names
 	 */
-	public ClassNameGenerator(Class<?> defaultTarget, String featureNamePrefix) {
+	public ClassNameGenerator(ClassName defaultTarget, String featureNamePrefix) {
 		this(defaultTarget, featureNamePrefix, new ConcurrentHashMap<>());
 	}
 
-	private ClassNameGenerator(Class<?> defaultTarget, String featureNamePrefix,
+	private ClassNameGenerator(ClassName defaultTarget, String featureNamePrefix,
 			Map<String, AtomicInteger> sequenceGenerator) {
 		Assert.notNull(defaultTarget, "'defaultTarget' must not be null");
 		this.defaultTarget = defaultTarget;
@@ -98,16 +98,16 @@ public final class ClassNameGenerator {
 	 * {@code null} to use the main target
 	 * @return a unique generated class name
 	 */
-	public ClassName generateClassName(String featureName, @Nullable Class<?> target) {
+	public ClassName generateClassName(String featureName, @Nullable ClassName target) {
 		return generateSequencedClassName(getRootName(featureName, target));
 	}
 
-	private String getRootName(String featureName, @Nullable Class<?> target) {
+	private String getRootName(String featureName, @Nullable ClassName target) {
 		Assert.hasLength(featureName, "'featureName' must not be empty");
 		featureName = clean(featureName);
-		Class<?> targetToUse = (target != null ? target : this.defaultTarget);
+		ClassName targetToUse = (target != null ? target : this.defaultTarget);
 		String featureNameToUse = this.featureNamePrefix + featureName;
-		return targetToUse.getName().replace("$", "_") + SEPARATOR + StringUtils.capitalize(featureNameToUse);
+		return toName(targetToUse).replace("$", "_") + SEPARATOR + StringUtils.capitalize(featureNameToUse);
 	}
 
 	private String clean(String name) {
@@ -147,4 +147,8 @@ public final class ClassNameGenerator {
 				this.sequenceGenerator);
 	}
 
+	private static String toName(ClassName className) {
+		return GeneratedTypeReference.of(className).getName();
+	}
+
 }

spring-core/src/main/java/org/springframework/aot/generate/GeneratedClasses.java

@@ -99,7 +99,7 @@ public class GeneratedClasses {
 	 * @return an existing or newly generated class
 	 */
 	public GeneratedClass getOrAddForFeatureComponent(String featureName,
-			Class<?> targetComponent, Consumer<TypeSpec.Builder> type) {
+			ClassName targetComponent, Consumer<TypeSpec.Builder> type) {
 
 		Assert.hasLength(featureName, "'featureName' must not be empty");
 		Assert.notNull(targetComponent, "'targetComponent' must not be null");
@@ -111,6 +111,24 @@ public class GeneratedClasses {
 		return generatedClass;
 	}
 
+	/**
+	 * Get or add a generated class for the specified {@code featureName}
+	 * targeting the specified {@code component}. If this method has previously
+	 * been called with the given {@code featureName}/{@code target} the
+	 * existing class will be returned, otherwise a new class will be generated,
+	 * otherwise a new class will be generated.
+	 * @param featureName the name of the feature to associate with the
+	 * generated class
+	 * @param targetComponent the target component
+	 * @param type a {@link Consumer} used to build the type
+	 * @return an existing or newly generated class
+	 */
+	public GeneratedClass getOrAddForFeatureComponent(String featureName,
+			Class<?> targetComponent, Consumer<TypeSpec.Builder> type) {
+
+		return getOrAddForFeatureComponent(featureName, ClassName.get(targetComponent), type);
+	}
+
 	/**
 	 * Add a new generated class for the specified {@code featureName} and no
 	 * particular component.
@@ -135,7 +153,7 @@ public class GeneratedClasses {
 	 * @return the newly generated class
 	 */
 	public GeneratedClass addForFeatureComponent(String featureName,
-			Class<?> targetComponent, Consumer<TypeSpec.Builder> type) {
+			ClassName targetComponent, Consumer<TypeSpec.Builder> type) {
 
 		Assert.hasLength(featureName, "'featureName' must not be empty");
 		Assert.notNull(targetComponent, "'targetComponent' must not be null");
@@ -143,8 +161,23 @@ public class GeneratedClasses {
 		return createAndAddGeneratedClass(featureName, targetComponent, type);
 	}
 
+	/**
+	 * Add a new generated class for the specified {@code featureName} targeting
+	 * the specified {@code component}.
+	 * @param featureName the name of the feature to associate with the
+	 * generated class
+	 * @param targetComponent the target component
+	 * @param type a {@link Consumer} used to build the type
+	 * @return the newly generated class
+	 */
+	public GeneratedClass addForFeatureComponent(String featureName,
+			Class<?> targetComponent, Consumer<TypeSpec.Builder> type) {
+
+		return addForFeatureComponent(featureName, ClassName.get(targetComponent), type);
+	}
+
 	private GeneratedClass createAndAddGeneratedClass(String featureName,
-			@Nullable Class<?> targetComponent, Consumer<TypeSpec.Builder> type) {
+			@Nullable ClassName targetComponent, Consumer<TypeSpec.Builder> type) {
 
 		ClassName className = this.classNameGenerator.generateClassName(featureName, targetComponent);
 		GeneratedClass generatedClass = new GeneratedClass(className, type);
@@ -171,7 +204,7 @@ public class GeneratedClasses {
 				this.classes, this.classesByOwner);
 	}
 
-	private record Owner(String featureNamePrefix, String featureName, @Nullable Class<?> target) {
+	private record Owner(String featureNamePrefix, String featureName, @Nullable ClassName target) {
 	}
 
 }