Modified the annotationHandler to use getCause but it always finds the innermost annotation

src/main/java/com/github/raychatter/AnnotationHandler.java

@@ -19,24 +19,24 @@ public class AnnotationHandler implements HandlerExceptionResolver {
    protected static final String DEFAULT_TEMPLATE = "defaults/default.template";
    private static final String UTF_8 = "UTF-8";
 
-   //TODO: When there's a wrapper exception leave it unannotated… call the e.getCause() method… until there is an annotated exception or if there are no more causes (e.geCause()==null)??.
-   /* If the exception thrown is annotated, use the message from that
-    * If it is not annotated, call getCause() until you reach the innermost annotated exception. Use that message.
-    * If getCause()==null, return the default message and response code
+   //TODO: When there's a wrapper exception leave it unannotated… call the e.getCause() method… until there is an annotated exception or if there are no more causes (e.geCause()==null)??
+   /* [ ] If the exception thrown is annotated, use the message from that
+    * [x] If it is not annotated, call getCause() until you reach the innermost annotated exception. Use that message.
+    * [ ] If getCause()==null, return the default message and response code
     */
    @Override
    public ModelAndView resolveException(final HttpServletRequest request, final HttpServletResponse response, final Object handler, final Exception thrownException) {
-      final ExceptionHandler annotation = getAnnotationFrom(thrownException);
+      Exception rootException = getRootException(thrownException, thrownException.getCause());
+      final ExceptionHandler annotation = getAnnotationFrom(rootException);
 
       try {
          if (annotation == null) {
-            thrownException.printStackTrace();
-            return respondWithDefault(thrownException, response);
+            rootException.printStackTrace();
+            return respondWithDefault(rootException, response);
          }
-
-         return handleException(annotation, thrownException, response);
+         return handleException(annotation, rootException, response);
       } catch (IOException e) {
-         // potentially something went wrong in response itself
+         // potentially something went wrong in the response itself
          e.printStackTrace();
       }
 
@@ -65,8 +65,16 @@ public class AnnotationHandler implements HandlerExceptionResolver {
       return new ModelAndView();
    }
 
-   protected ExceptionHandler getAnnotationFrom(Exception thrownException) {
-      return thrownException.getClass().getAnnotation(ExceptionHandler.class);
+   protected Exception getRootException(Exception thrownException, Throwable causedException) {
+      if(causedException == null || getAnnotationFrom((Exception)causedException)==null) {
+         return thrownException;
+      } else {
+         return getRootException((Exception) causedException, causedException.getCause());
+      }
+   }
+
+   protected ExceptionHandler getAnnotationFrom(Exception exception) {
+      return exception.getClass().getAnnotation(ExceptionHandler.class);
    }
 
    protected String formatMessage(final Exception thrownException) throws IOException {

src/test/java/com/github/raychatter/AnnotationHandlerTest.java

@@ -13,7 +13,12 @@ import java.io.InputStream;
 import java.io.PrintWriter;
 
 import static org.mockito.Matchers.anyString;
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class AnnotationHandlerTest {
 
@@ -234,6 +239,7 @@ public class AnnotationHandlerTest {
 
       final AnnotationHandler sut = spy(new AnnotationHandler());
       doReturn(new ModelAndView()).when(sut).handleException(mockAnnotation, expectedException, mockResponse);
+      doReturn(expectedException).when(sut).getRootException(expectedException, expectedException.getCause());
       doReturn(mockAnnotation).when(sut).getAnnotationFrom(expectedException);
 
       final ModelAndView view = sut.resolveException(null, mockResponse, null, expectedException);
@@ -249,12 +255,36 @@ public class AnnotationHandlerTest {
       when(mockResponse.getWriter()).thenReturn(mockPrinter);
 
       final AnnotationHandler sut = spy(new AnnotationHandler());
-      doReturn(null).when(sut).getAnnotationFrom(expectedException);
+      when(sut.getRootException(expectedException, expectedException.getCause())).thenReturn(expectedException);
+      when(sut.getAnnotationFrom(expectedException)).thenReturn(null);
 
       final ModelAndView view = sut.resolveException(null, mockResponse, null, expectedException);
 
       verify(sut).respondWithDefault(expectedException, mockResponse);
    }
+
+   // TODO: Mock the getCause() method to return TestExceptionWithNoAnnotation
+   // Instead of the actual exception, use the getCause() mocked one
+   // To pass into the annotationHandler method
+   // Check that the response is the correct message
+   @Test public void resolveException_ShouldReturnRootCheckedExceptionErrorMessage_WhenThereAreCheckedExceptionsChained() throws Exception {
+      TestExceptionWithNoAnnotationAttributes mockException = mock(TestExceptionWithNoAnnotationAttributes.class);
+      TestExceptionWithNoContentStatusCodeAndTextContentType mockCauseException = mock(TestExceptionWithNoContentStatusCodeAndTextContentType.class);
+      doReturn(mockCauseException).when(mockException).getCause();
+      doReturn(new TestExceptionWithNoAnnotation("")).when(mockCauseException).getCause();
+
+      final ExceptionHandler mockAnnotation = mock(ExceptionHandler.class);
+      final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
+
+      final AnnotationHandler sut = spy(new AnnotationHandler());
+      when(sut.getAnnotationFrom(mockCauseException)).thenReturn(mockAnnotation);
+      when(sut.getRootException(mockException, mockException.getCause())).thenReturn(mockCauseException);
+      doReturn(new ModelAndView()).when(sut).handleException(mockAnnotation, mockCauseException, mockResponse);
+
+      final ModelAndView view = sut.resolveException(null, mockResponse, null, mockException);
+
+      verify(sut).handleException(mockAnnotation, mockCauseException, mockResponse);   //TestExceptionWithNoContentStatusCodeAndTextContentType
+   }
 }
 
 @ExceptionHandler()
@@ -277,5 +307,14 @@ class TestExceptionWithNoContentStatusCodeAndTextContentType extends Exception {
    public TestExceptionWithNoContentStatusCodeAndTextContentType(final String s) {
       super(s);
    }
+
+   public TestExceptionWithNoContentStatusCodeAndTextContentType(final String s, Throwable ex) {
+      super(s,ex);
+   }
 }
 
+class TestExceptionWithNoAnnotation extends Exception {
+   public TestExceptionWithNoAnnotation(final String s) {
+      super(s);
+   }
+}