Increased test coverage

exception-handler/src/main/java/com/raychatter/common/annotation/AnnotationHandler.java

@@ -1,6 +1,8 @@
 package com.raychatter.common.annotation;
 
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.web.servlet.HandlerExceptionResolver;
 import org.springframework.web.servlet.ModelAndView;
 
@@ -12,23 +14,28 @@ import java.util.Scanner;
 
 public class AnnotationHandler implements HandlerExceptionResolver {
 
-   protected static final String DEFAULT_ERROR_STRING = "Error: %s";
+   protected static final String DEFAULT_ERROR_STRING = "<error>%s</error>";
    protected static final String USER_TEMPLATE = "error.template";
    protected static final String DEFAULT_TEMPLATE = "defaults/default.template";
    private static final String UTF_8 = "UTF-8";
 
    @Override
    public ModelAndView resolveException(final HttpServletRequest request, final HttpServletResponse response, final Object handler, final Exception thrownException) {
-      final ExceptionHandler annotation = thrownException.getClass().getAnnotation(ExceptionHandler.class);
+      final ExceptionHandler annotation = getAnnotationFrom(thrownException);
 
-      if (annotation == null) {
+      if (annotation == null) return new ModelAndView();
-         return new ModelAndView();
+
+      try {
+         return handleException(annotation, thrownException, response);
+      } catch (IOException e) {
+         // potentially something went wrong in response itself
+         e.printStackTrace();
       }
 
-      return handleException(annotation, thrownException, response);
+      return new ModelAndView();
    }
 
-   protected ModelAndView handleException(final ExceptionHandler annotation, final Exception thrownException, final HttpServletResponse response) {
+   protected ModelAndView handleException(final ExceptionHandler annotation, final Exception thrownException, final HttpServletResponse response) throws IOException {
       response.setContentType(annotation.contentType());
       response.setStatus(annotation.httpStatus().value());
 
@@ -36,20 +43,18 @@ public class AnnotationHandler implements HandlerExceptionResolver {
          final String message = formatMessage(thrownException);
          response.getWriter().write(message);
       } catch (IOException e) {
-         //TODO: Potentially this can be handled differently than the template errors
+         response.setContentType(MediaType.APPLICATION_XML_VALUE);
-//         response.setContentType(MediaType.APPLICATION_XML_VALUE);
+         response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
-//         response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
+         response.getWriter().write(formatDefaultMessage(thrownException));
-//
-//         try {
-//            response.getWriter().write(formatDefaultMessage(thrownException));
-//         } catch (IOException ex) {
-//            ex.printStackTrace();
-//         }
       }
 
       return new ModelAndView();
    }
 
+   protected ExceptionHandler getAnnotationFrom(Exception thrownException) {
+      return thrownException.getClass().getAnnotation(ExceptionHandler.class);
+   }
+
    protected String formatMessage(final Exception thrownException) throws IOException {
       return String.format(readTemplate(), thrownException.getMessage());
    }

exception-handler/src/main/java/com/raychatter/common/annotation/ExceptionHandler.java

@@ -19,5 +19,5 @@ import java.lang.annotation.Target;
       ElementType.TYPE})
 public @interface ExceptionHandler {
    HttpStatus httpStatus() default HttpStatus.INTERNAL_SERVER_ERROR;
-   String contentType() default MediaType.TEXT_PLAIN_VALUE;
+   String contentType() default MediaType.APPLICATION_XML_VALUE;
 }

exception-handler/src/test/java/com/raychatter/common/annotation/AnnotationHandlerTest.java

@@ -4,6 +4,7 @@ import junit.framework.Assert;
 import org.junit.Test;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.web.servlet.ModelAndView;
 
 import javax.servlet.http.HttpServletResponse;
 import java.io.ByteArrayInputStream;
@@ -12,12 +13,7 @@ import java.io.InputStream;
 import java.io.PrintWriter;
 
 import static org.mockito.Matchers.anyString;
-import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.*;
-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 {
 
@@ -93,7 +89,8 @@ public class AnnotationHandlerTest {
       Assert.assertEquals(expectedDefaultTemplateString, actual);
    }
 
-   @Test public void handleException_ShouldRenderDefaultContentType_WhenNoAnnotationAttributesGiven() throws Exception {
+   @Test
+   public void handleException_ShouldRenderDefaultContentType_WhenNoAnnotationAttributesGiven() throws Exception {
       final String emptyString = "";
 
       final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
@@ -106,10 +103,11 @@ public class AnnotationHandlerTest {
 
       sut.handleException(TestExceptionWithNoAnnotationAttributes.class.getAnnotation(ExceptionHandler.class), null, mockResponse);
 
-      verify(mockResponse).setContentType(MediaType.TEXT_PLAIN_VALUE);
+      verify(mockResponse).setContentType(MediaType.APPLICATION_XML_VALUE);
    }
 
-   @Test public void handleException_ShouldRenderDefaultHttpStatusCode_WhenNoAnnotationAttributesGiven() throws Exception {
+   @Test
+   public void handleException_ShouldRenderDefaultHttpStatusCode_WhenNoAnnotationAttributesGiven() throws Exception {
       final String emptyString = "";
 
       final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
@@ -125,7 +123,8 @@ public class AnnotationHandlerTest {
       verify(mockResponse).setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
    }
 
-   @Test public void handleException_ShouldRenderNotFoundHttpStatusCode_WhenNotFoundAnnotationAttributeIsGiven() throws Exception {
+   @Test
+   public void handleException_ShouldRenderNotFoundHttpStatusCode_WhenNotFoundAnnotationAttributeIsGiven() throws Exception {
       final String emptyString = "";
 
       final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
@@ -141,7 +140,8 @@ public class AnnotationHandlerTest {
       verify(mockResponse).setStatus(HttpStatus.NOT_FOUND.value());
    }
 
-   @Test public void handleException_ShouldRenderXmlContentType_WhenXmlContentTypeAnnotationAttributeIsGiven() throws Exception {
+   @Test
+   public void handleException_ShouldRenderXmlContentType_WhenXmlContentTypeAnnotationAttributeIsGiven() throws Exception {
       final String emptyString = "";
 
       final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
@@ -157,7 +157,8 @@ public class AnnotationHandlerTest {
       verify(mockResponse).setContentType(MediaType.APPLICATION_XML_VALUE);
    }
 
-   @Test public void handleException_ShouldRenderUserMessage_WhenUserTemplateIsGiven() throws Exception {
+   @Test
+   public void handleException_ShouldRenderUserMessage_WhenUserTemplateIsGiven() throws Exception {
       final String expectedUserTemplate = "USER TEMPLATE: %s";
       final String expectedErrorMessage = "ERROR MESSAGE";
       final String expectedErrorBody = "USER TEMPLATE: ERROR MESSAGE";
@@ -175,6 +176,70 @@ public class AnnotationHandlerTest {
       verify(mockPrinter).write(expectedErrorBody);
    }
 
+   @Test
+   public void handleException_ShouldReturnXmlContentType_WhenNoUserTemplateGiven() throws Exception {
+      final String emptyString = "";
+      final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
+      final PrintWriter mockPrinter = mock(PrintWriter.class);
+      when(mockResponse.getWriter()).thenReturn(mockPrinter);
+
+      final AnnotationHandler sut = spy(new AnnotationHandler());
+      doThrow(IOException.class).when(sut).getResource(AnnotationHandler.USER_TEMPLATE);
+      doReturn(emptyString).when(sut).formatDefaultMessage(null);
+
+      sut.handleException(TestExceptionWithNoContentStatusCodeAndTextContentType.class.getAnnotation(ExceptionHandler.class), null, mockResponse);
+
+      verify(mockResponse).setContentType(MediaType.APPLICATION_XML_VALUE);
+   }
+
+   @Test
+   public void handleException_ShouldReturnInternalServerErrorStatusCode_WhenNoUserTemplateGiven() throws Exception {
+      final String emptyString = "";
+      final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
+      final PrintWriter mockPrinter = mock(PrintWriter.class);
+      when(mockResponse.getWriter()).thenReturn(mockPrinter);
+
+      final AnnotationHandler sut = spy(new AnnotationHandler());
+      doThrow(IOException.class).when(sut).getResource(AnnotationHandler.USER_TEMPLATE);
+      doReturn(emptyString).when(sut).formatDefaultMessage(null);
+
+      sut.handleException(TestExceptionWithNoContentStatusCodeAndTextContentType.class.getAnnotation(ExceptionHandler.class), null, mockResponse);
+
+      verify(mockResponse).setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
+   }
+
+   @Test
+   public void handleException_ShouldRenderDefaultTemplate_WhenNoUserTemplateGiven() throws Exception {
+      final String expectedDefaultTemplate = "DEFAULT TEMPLATE: %s";
+      final String expectedErrorMessage = "ERROR MESSAGE";
+      final String expectedErrorBody = "DEFAULT TEMPLATE: ERROR MESSAGE";
+      final TestExceptionWithNoContentStatusCodeAndTextContentType expectedException = new TestExceptionWithNoContentStatusCodeAndTextContentType(expectedErrorMessage);
+      final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
+      final PrintWriter mockPrinter = mock(PrintWriter.class);
+      when(mockResponse.getWriter()).thenReturn(mockPrinter);
+
+      final AnnotationHandler sut = spy(new AnnotationHandler());
+      doThrow(IOException.class).when(sut).getResource(AnnotationHandler.USER_TEMPLATE);
+      doReturn(new ByteArrayInputStream(expectedDefaultTemplate.getBytes())).when(sut).getResource(AnnotationHandler.DEFAULT_TEMPLATE);
+
+      sut.handleException(expectedException.getClass().getAnnotation(ExceptionHandler.class), expectedException, mockResponse);
+
+      verify(mockPrinter).write(expectedErrorBody);
+   }
+
+   @Test public void resolveException_ShouldReturnCustomErrorMessage_WhenValidExceptionWithAnnotationIsGiven() throws Exception {
+      final ExceptionHandler mockAnnotation = mock(ExceptionHandler.class);
+      final HttpServletResponse mockResponse = mock(HttpServletResponse.class);
+      final TestExceptionWithNoAnnotationAttributes expectedException = new TestExceptionWithNoAnnotationAttributes("");
+
+      final AnnotationHandler sut = spy(new AnnotationHandler());
+      doReturn(new ModelAndView()).when(sut).handleException(mockAnnotation, expectedException, mockResponse);
+      doReturn(mockAnnotation).when(sut).getAnnotationFrom(expectedException);
+
+      final ModelAndView view = sut.resolveException(null, mockResponse, null, expectedException);
+
+      verify(sut).handleException(mockAnnotation, expectedException, mockResponse);
+   }
 }
 
 @ExceptionHandler()
@@ -185,8 +250,17 @@ class TestExceptionWithNoAnnotationAttributes extends Exception {
 }
 
 @ExceptionHandler(contentType = MediaType.APPLICATION_XML_VALUE)
-class TestExceptionWithXmlContentType extends Exception { }
+class TestExceptionWithXmlContentType extends Exception {
+}
 
 @ExceptionHandler(httpStatus = HttpStatus.NOT_FOUND)
-class TestExceptionWithNotFoundStatusCode extends Exception { }
+class TestExceptionWithNotFoundStatusCode extends Exception {
+}
+
+@ExceptionHandler(contentType = MediaType.TEXT_PLAIN_VALUE, httpStatus = HttpStatus.NO_CONTENT)
+class TestExceptionWithNoContentStatusCodeAndTextContentType extends Exception {
+   public TestExceptionWithNoContentStatusCodeAndTextContentType(final String s) {
+      super(s);
+   }
+}
 

sample/src/main/webapp/WEB-INF/mvc-dispatcher-servlet.xml

@@ -20,6 +20,6 @@
 		</property>
 	</bean>
 
-   <bean id="exceptionResolver" class="com.raychatter.common.exception.AnnotationHandler" />
+   <bean id="exceptionResolver" class="com.raychatter.common.annotation.AnnotationHandler" />
 
 </beans>