fixed @ExceptionHandler exception type matching (ExceptionDepthComparator; SPR-8231)

org.springframework.core/src/main/java/org/springframework/core/ExceptionDepthComparator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -68,7 +68,7 @@ public class ExceptionDepthComparator implements Comparator<Class<? extends Thro
 		}
 		// If we've gone as far as we can go and haven't found it...
 		if (Throwable.class.equals(exceptionToMatch)) {
-			return -1;
+			return Integer.MAX_VALUE;
 		}
 		return getDepth(declaredException, exceptionToMatch.getSuperclass(), depth + 1);
 	}

org.springframework.core/src/test/java/org/springframework/core/ExceptionDepthComparatorTests.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2002-2011 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.core;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Juergen Hoeller
+ * @author Chris Shepperd
+ */
+public class ExceptionDepthComparatorTests {
+
+  @Test
+  public void targetBeforeSameDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(TargetException.class, SameDepthException.class);
+    assertEquals(TargetException.class, foundClass);
+  }
+
+  @Test
+  public void sameDepthBeforeTarget() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(SameDepthException.class, TargetException.class);
+    assertEquals(TargetException.class, foundClass);
+  }
+
+  @Test
+  public void lowestDepthBeforeTarget() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(LowestDepthException.class, TargetException.class);
+    assertEquals(TargetException.class, foundClass);
+  }
+
+  @Test
+  public void targetBeforeLowestDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(TargetException.class, LowestDepthException.class);
+    assertEquals(TargetException.class, foundClass);
+  }
+
+  @Test
+  public void noDepthBeforeTarget() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(NoDepthException.class, TargetException.class);
+    assertEquals(TargetException.class, foundClass);
+  }
+
+  @Test
+  public void noDepthBeforeHighestDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(NoDepthException.class, HighestDepthException.class);
+    assertEquals(HighestDepthException.class, foundClass);
+  }
+
+  @Test
+  public void highestDepthBeforeNoDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(HighestDepthException.class, NoDepthException.class);
+    assertEquals(HighestDepthException.class, foundClass);
+  }
+
+  @Test
+  public void highestDepthBeforeLowestDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(HighestDepthException.class, LowestDepthException.class);
+    assertEquals(LowestDepthException.class, foundClass);
+  }
+
+  @Test
+  public void lowestDepthBeforeHighestDepth() throws Exception {
+    Class<? extends Throwable> foundClass = findClosestMatch(LowestDepthException.class, HighestDepthException.class);
+    assertEquals(LowestDepthException.class, foundClass);
+  }
+
+  private Class<? extends Throwable> findClosestMatch(Class<? extends Throwable>... classes) {
+    return ExceptionDepthComparator.findClosestMatch(Arrays.asList(classes), new TargetException());
+  }
+
+
+  public class HighestDepthException extends Throwable {
+  }
+
+  public class LowestDepthException extends HighestDepthException {
+  }
+
+  public class TargetException extends LowestDepthException {
+  }
+
+  public class SameDepthException extends LowestDepthException {
+  }
+
+  public class NoDepthException extends TargetException {
+  }
+
+}