Circular @Imports are now handled by registering a Problem...

Circular @Imports are now handled by registering a Problem (CircularImportProblem) as an error with the current ProblemReporter.  This eliminates the need for CircularImportException and is a more tooling-friendly approach.

org.springframework.config.java/src/main/java/org/springframework/config/java/support/CircularImportException.java

-/*
- * Copyright 2002-2009 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.springframework.config.java.support;
-
-import static java.lang.String.*;
-
-import java.util.Stack;
-
-
-/**
- * Thrown by {@link ConfigurationParser} upon detecting circular use of the {@link Import} annotation.
- * 
- * @author Chris Beams
- * @see Import
- * @see ImportStack
- * @see ImportStackHolder
- */
-@SuppressWarnings("serial")
-class CircularImportException extends IllegalStateException {
-	public CircularImportException(ConfigurationClass attemptedImport, Stack<ConfigurationClass> currentImportStack) {
-		super(format("A circular @Import has been detected: " +
-		             "Illegal attempt by @Configuration class '%s' to import class '%s' as '%s' is " +
-		             "already present in the current import stack [%s]",
-		             currentImportStack.peek().getSimpleName(), attemptedImport.getSimpleName(),
-		             attemptedImport.getSimpleName(), currentImportStack));
-	}
-}

org.springframework.config.java/src/main/java/org/springframework/config/java/support/ConfigurationClassPostProcessor.java

@@ -104,7 +104,7 @@ public class ConfigurationClassPostProcessor extends AbstractConfigurationClassP
 	 */
 	@Override
 	protected ConfigurationParser createConfigurationParser() {
-		return new ConfigurationParser(beanFactory.getBeanClassLoader());
+		return new ConfigurationParser(this.getProblemReporter(), beanFactory.getBeanClassLoader());
 	}
 
 	/**

org.springframework.config.java/src/main/java/org/springframework/config/java/support/ConfigurationClassVisitor.java

@@ -15,20 +15,27 @@
  */
 package org.springframework.config.java.support;
 
+import static java.lang.String.*;
 import static org.springframework.config.java.support.MutableAnnotationUtils.*;
 import static org.springframework.config.java.support.Util.*;
 import static org.springframework.util.ClassUtils.*;
 
 import java.lang.annotation.Annotation;
 import java.util.HashMap;
+import java.util.Stack;
 
 import org.springframework.asm.AnnotationVisitor;
 import org.springframework.asm.ClassAdapter;
 import org.springframework.asm.ClassReader;
 import org.springframework.asm.MethodVisitor;
 import org.springframework.asm.Opcodes;
+import org.springframework.asm.commons.EmptyVisitor;
+import org.springframework.beans.factory.parsing.Location;
+import org.springframework.beans.factory.parsing.Problem;
+import org.springframework.beans.factory.parsing.ProblemReporter;
 import org.springframework.config.java.Configuration;
 import org.springframework.config.java.Import;
+import org.springframework.core.io.FileSystemResource;
 
 
 /**
@@ -43,15 +50,18 @@ class ConfigurationClassVisitor extends ClassAdapter {
 
 	private final ConfigurationClass configClass;
 	private final ConfigurationModel model;
+	private final ProblemReporter problemReporter;
 	private final HashMap<String, ConfigurationClass> innerClasses = new HashMap<String, ConfigurationClass>();
 
 	private boolean processInnerClasses = true;
 	private final ClassLoader classLoader;
 
-	public ConfigurationClassVisitor(ConfigurationClass configClass, ConfigurationModel model, ClassLoader classLoader) {
+	public ConfigurationClassVisitor(ConfigurationClass configClass, ConfigurationModel model,
+	                                 ProblemReporter problemReporter, ClassLoader classLoader) {
 		super(AsmUtils.EMPTY_VISITOR);
 		this.configClass = configClass;
 		this.model = model;
+		this.problemReporter = problemReporter;
 		this.classLoader = classLoader;
 	}
 
@@ -86,7 +96,8 @@ class ConfigurationClassVisitor extends ClassAdapter {
 		if (OBJECT_DESC.equals(superTypeDesc))
 			return;
 
-		ConfigurationClassVisitor visitor = new ConfigurationClassVisitor(configClass, model, classLoader);
+		ConfigurationClassVisitor visitor =
+			new ConfigurationClassVisitor(configClass, model, problemReporter, classLoader);
 
 		ClassReader reader = AsmUtils.newClassReader(superTypeDesc, classLoader);
 		reader.accept(visitor, false);
@@ -116,12 +127,15 @@ class ConfigurationClassVisitor extends ClassAdapter {
 		if (Import.class.getName().equals(annoTypeName)) {
 			ImportStack importStack = ImportStackHolder.getImportStack();
 
-			if (importStack.contains(configClass))
-				throw new CircularImportException(configClass, importStack);
+			if (importStack.contains(configClass)) {
+				//throw new CircularImportException(configClass, importStack);
+				problemReporter.error(new CircularImportProblem(configClass, importStack));
+				return new EmptyVisitor();
+			}
 
 			importStack.push(configClass);
 
-			return new ImportAnnotationVisitor(model, classLoader);
+			return new ImportAnnotationVisitor(model, problemReporter, classLoader);
 		}
 
 		/* -------------------------------------
@@ -217,7 +231,7 @@ class ConfigurationClassVisitor extends ClassAdapter {
 		ConfigurationClass innerConfigClass = new ConfigurationClass();
 
 		ConfigurationClassVisitor ccVisitor =
-			new ConfigurationClassVisitor(innerConfigClass, new ConfigurationModel(), classLoader);
+			new ConfigurationClassVisitor(innerConfigClass, new ConfigurationModel(), problemReporter, classLoader);
 		ccVisitor.setProcessInnerClasses(false);
 
 		ClassReader reader = AsmUtils.newClassReader(name, classLoader);
@@ -230,4 +244,27 @@ class ConfigurationClassVisitor extends ClassAdapter {
 		if (innerConfigClass.getMetadata() != null)
 			innerClasses.put(name, innerConfigClass);
 	}
+
+
+	/**
+	 * {@link Problem} registered upon detection of a circular {@link Import}.
+	 * 
+	 * @see Import
+	 * @see ImportStack
+	 * @see ImportStackHolder
+	 */
+	class CircularImportProblem extends Problem {
+
+		public CircularImportProblem(ConfigurationClass attemptedImport, Stack<ConfigurationClass> currentImportStack) {
+			super(format("A circular @Import has been detected: " +
+			             "Illegal attempt by @Configuration class '%s' to import class '%s' as '%s' is " +
+			             "already present in the current import stack [%s]",
+			             currentImportStack.peek().getSimpleName(), attemptedImport.getSimpleName(),
+			             attemptedImport.getSimpleName(), currentImportStack),
+			      new Location(new FileSystemResource("/dev/null"))
+			);
+		}
+
+	}
+
 }

org.springframework.config.java/src/main/java/org/springframework/config/java/support/ConfigurationParser.java

@@ -17,6 +17,7 @@ package org.springframework.config.java.support;
 
 import org.springframework.asm.ClassReader;
 import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.parsing.ProblemReporter;
 import org.springframework.config.java.Configuration;
 import org.springframework.util.ClassUtils;
 
@@ -41,17 +42,18 @@ public class ConfigurationParser {
 	 * Model to be populated during calls to {@link #parse(Object, String)}
 	 */
 	private final ConfigurationModel model;
+	private final ProblemReporter problemReporter;
 	private final ClassLoader classLoader;
 
 	/**
 	 * Creates a new parser instance that will be used to populate <var>model</var>.
-	 * 
 	 * @param model model to be populated by each successive call to
 	 *        {@link #parse(Object, String)}
 	 */
-	public ConfigurationParser(ClassLoader classLoader) {
-		this.classLoader = classLoader;
+	public ConfigurationParser(ProblemReporter problemReporter, ClassLoader classLoader) {
 		this.model = new ConfigurationModel();
+		this.problemReporter = problemReporter;
+		this.classLoader = classLoader;
 	}
 
 	/**
@@ -71,7 +73,7 @@ public class ConfigurationParser {
 		ConfigurationClass configClass = new ConfigurationClass();
 		configClass.setBeanName(configurationId);
 
-		configClassReader.accept(new ConfigurationClassVisitor(configClass, model, classLoader), false);
+		configClassReader.accept(new ConfigurationClassVisitor(configClass, model, problemReporter, classLoader), false);
 		model.add(configClass);
 	}
 

org.springframework.config.java/src/main/java/org/springframework/config/java/support/ImportAnnotationVisitor.java

@@ -24,6 +24,7 @@ import java.util.ArrayList;
 import org.springframework.asm.AnnotationVisitor;
 import org.springframework.asm.ClassReader;
 import org.springframework.asm.Type;
+import org.springframework.beans.factory.parsing.ProblemReporter;
 import org.springframework.config.java.Import;
 import org.springframework.util.Assert;
 
@@ -42,11 +43,13 @@ import org.springframework.util.Assert;
 class ImportAnnotationVisitor extends AnnotationAdapter {
 	private final ArrayList<String> classesToImport = new ArrayList<String>();
 	private final ConfigurationModel model;
+	private final ProblemReporter problemReporter;
 	private final ClassLoader classLoader;
 
-	public ImportAnnotationVisitor(ConfigurationModel model, ClassLoader classLoader) {
+	public ImportAnnotationVisitor(ConfigurationModel model, ProblemReporter problemReporter, ClassLoader classLoader) {
 		super(AsmUtils.EMPTY_VISITOR);
 		this.model = model;
+		this.problemReporter = problemReporter;
 		this.classLoader = classLoader;
 	}
 
@@ -77,7 +80,7 @@ class ImportAnnotationVisitor extends AnnotationAdapter {
 
 		ClassReader reader = newClassReader(convertClassNameToResourcePath(classToImport), classLoader);
 
-		reader.accept(new ConfigurationClassVisitor(configClass, model, classLoader), false);
+		reader.accept(new ConfigurationClassVisitor(configClass, model, problemReporter, classLoader), false);
 
 		model.add(configClass);
 	}

org.springframework.config.java/src/test/java/org/springframework/config/java/support/AbstractCircularImportDetectionTests.java

@@ -18,6 +18,7 @@ package org.springframework.config.java.support;
 import static org.junit.Assert.*;
 
 import org.junit.Test;
+import org.springframework.beans.factory.parsing.BeanDefinitionParsingException;
 import org.springframework.config.java.Bean;
 import org.springframework.config.java.Import;
 
@@ -40,7 +41,7 @@ public abstract class AbstractCircularImportDetectionTests {
 		boolean threw = false;
 		try {
 			newParser().parse(loadAsConfigurationSource(A.class), null);
-		} catch (CircularImportException ex) {
+		} catch (BeanDefinitionParsingException ex) {
 			assertTrue("Wrong message. Got: " + ex.getMessage(),
 					ex.getMessage().contains(
 						"Illegal attempt by @Configuration class 'AbstractCircularImportDetectionTests.B' " +
@@ -57,7 +58,7 @@ public abstract class AbstractCircularImportDetectionTests {
 		boolean threw = false;
 		try {
 			newParser().parse(loadAsConfigurationSource(X.class), null);
-		} catch (CircularImportException ex) {
+		} catch (BeanDefinitionParsingException ex) {
 			assertTrue("Wrong message. Got: " + ex.getMessage(),
 					ex.getMessage().contains(
 						"Illegal attempt by @Configuration class 'AbstractCircularImportDetectionTests.Z2' " +

org.springframework.config.java/src/test/java/org/springframework/config/java/support/AsmCircularImportDetectionTests.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.config.java.support;
 
+import org.springframework.beans.factory.parsing.FailFastProblemReporter;
 import org.springframework.config.java.Import;
 import org.springframework.util.ClassUtils;
 
@@ -32,7 +33,7 @@ import org.springframework.util.ClassUtils;
 public class AsmCircularImportDetectionTests extends AbstractCircularImportDetectionTests {
 	@Override
 	protected ConfigurationParser newParser() {
-		return new ConfigurationParser(ClassUtils.getDefaultClassLoader());
+		return new ConfigurationParser(new FailFastProblemReporter(), ClassUtils.getDefaultClassLoader());
 	}
 
 	@Override