feat: 404 페이지 반환 구현

app/src/main/java/com/techcourse/DispatcherServletInitializer.java

@@ -17,7 +17,7 @@ public class DispatcherServletInitializer implements WebApplicationInitializer {
 
     @Override
     public void onStartup(final ServletContext servletContext) {
-        final var dispatcherServlet = new DispatcherServlet();
+        final var dispatcherServlet = new DispatcherServlet("com.techcourse.controller", "/404.jsp");
 
         final var registration = servletContext.addServlet(DEFAULT_SERVLET_NAME, dispatcherServlet);
         if (registration == null) {

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/dispatcherservlet/DispatcherServlet.java

@@ -10,6 +10,7 @@
 import webmvc.org.springframework.web.servlet.mvc.tobe.AnnotationHandlerMapping;
 import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerAdapterRegistry;
 import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerMappingRegistry;
+import webmvc.org.springframework.web.servlet.mvc.tobe.NotFoundHandlerAdapter;
 
 public class DispatcherServlet extends HttpServlet {
 
@@ -19,9 +20,9 @@ public class DispatcherServlet extends HttpServlet {
     private final HandlerMappingRegistry handlerMappingRegistry;
     private final HandlerAdapterRegistry handlerAdapterRegistry;
 
-    public DispatcherServlet() {
-        handlerAdapterRegistry = new HandlerAdapterRegistry(new AnnotationHandlerAdapter());
-        handlerMappingRegistry = new HandlerMappingRegistry(new AnnotationHandlerMapping("com.techcourse.controller"));
+    public DispatcherServlet(String basePackage, String notFoundViewName) {
+        handlerAdapterRegistry = new HandlerAdapterRegistry(new AnnotationHandlerAdapter(), new NotFoundHandlerAdapter(notFoundViewName));
+        handlerMappingRegistry = new HandlerMappingRegistry(new AnnotationHandlerMapping(basePackage));
     }
 
     @Override

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/HandlerMappingRegistry.java

@@ -23,6 +23,6 @@ public Object getHandler(HttpServletRequest request) {
                               .map(handler -> handler.getHandler(request))
                               .filter(Objects::nonNull)
                               .findFirst()
-                              .orElseThrow(() -> new IllegalArgumentException("존재하지 않는 URL입니다."));
+                              .orElse(new NotFoundHandler());
     }
 }

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/NotFoundHandler.java

@@ -0,0 +1,11 @@
+package webmvc.org.springframework.web.servlet.mvc.tobe;
+
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.view.JspView;
+
+public class NotFoundHandler {
+
+    public ModelAndView handle(String viewName) {
+        return new ModelAndView(new JspView(viewName));
+    }
+}

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/NotFoundHandlerAdapter.java

@@ -0,0 +1,24 @@
+package webmvc.org.springframework.web.servlet.mvc.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+
+public class NotFoundHandlerAdapter implements HandlerAdapter {
+
+    private final String viewName;
+
+    public NotFoundHandlerAdapter(String viewName) {
+        this.viewName = viewName;
+    }
+
+    @Override
+    public boolean supports(Object handler) {
+        return handler instanceof NotFoundHandler;
+    }
+
+    @Override
+    public ModelAndView handle(Object handler, HttpServletRequest request, HttpServletResponse response) throws Exception {
+        return ((NotFoundHandler) handler).handle(viewName);
+    }
+}