[MVC 구현하기 - 1단계] 마코(이규성) 미션 제출합니다.

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/exception/CanNotInstanceHandlerException.java

@@ -0,0 +1,5 @@
+package webmvc.org.springframework.web.servlet.mvc.exception;
+
+public class CanNotInstanceHandlerException extends RuntimeException {
+
+}

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

@@ -1,15 +1,27 @@
 package webmvc.org.springframework.web.servlet.mvc.tobe;
 
+import context.org.springframework.stereotype.Controller;
 import jakarta.servlet.http.HttpServletRequest;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
+import jakarta.servlet.http.HttpServletResponse;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import org.reflections.Reflections;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import web.org.springframework.web.bind.annotation.RequestMapping;
+import web.org.springframework.web.bind.annotation.RequestMethod;
+import webmvc.org.springframework.web.servlet.mvc.exception.CanNotInstanceHandlerException;
 
 public class AnnotationHandlerMapping {
 
     private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
+    private static final Set<Class<?>> supportParameters = Set.of(HttpServletRequest.class,
+            HttpServletResponse.class);
 
     private final Object[] basePackage;
     private final Map<HandlerKey, HandlerExecution> handlerExecutions;
@@ -20,10 +32,53 @@ public AnnotationHandlerMapping(final Object... basePackage) {
     }
 
     public void initialize() {
+        final var reflections = new Reflections(basePackage);
+        final var classes = reflections.getTypesAnnotatedWith(Controller.class);
+        for (final Class<?> clazz : classes) {
+            final var handler = getHandlerInstance(clazz);
+            final var methods = clazz.getMethods();
+
+            Arrays.stream(methods)
+                    .filter(this::supportParameters)
+                    .filter(method -> method.isAnnotationPresent(RequestMapping.class))
+                    .forEach(method -> putHandlerExecutions(handler, method));
+        }
         log.info("Initialized AnnotationHandlerMapping!");
     }
 
+    private boolean supportParameters(final Method method) {
+        final var parameterTypes = Arrays.stream(method.getParameterTypes())
+                .collect(Collectors.toList());
+
+        return supportParameters.containsAll(parameterTypes) && parameterTypes.size() == 2;
+    }
+
+    private void putHandlerExecutions(final Object handler, final Method method) {
+        final var annotation = method.getDeclaredAnnotation(RequestMapping.class);
+        final var handlerExecution = new HandlerExecution(handler, method);
+
+        Arrays.stream(annotation.method())
+                .map(requestMethod -> new HandlerKey(annotation.value(), requestMethod))
+                .forEach(handlerKey -> handlerExecutions.put(handlerKey, handlerExecution));
+    }
+
+    private static Object getHandlerInstance(final Class<?> clazz) {
+        try {
+            return clazz.getConstructor().newInstance();
+        } catch (NoSuchMethodException |
+                IllegalAccessException |
+                InstantiationException |
+                 InvocationTargetException e
+        ) {
+            throw new CanNotInstanceHandlerException();
+        }
+    }
+
     public Object getHandler(final HttpServletRequest request) {
-        return null;
+        String requestURI = request.getRequestURI();
+        RequestMethod requestMethod = RequestMethod.valueOf(request.getMethod());
+        HandlerKey handlerKey = new HandlerKey(requestURI, requestMethod);
+
+        return handlerExecutions.get(handlerKey);
     }
 }

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

@@ -2,11 +2,21 @@
 
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
+import java.lang.reflect.Method;
 import webmvc.org.springframework.web.servlet.ModelAndView;
 
 public class HandlerExecution {
 
-    public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        return null;
+    private final Object handler;
+    private final Method method;
+
+    public HandlerExecution(final Object handler, final Method method) {
+        this.handler = handler;
+        this.method = method;
+    }
+
+    public ModelAndView handle(final HttpServletRequest request, final HttpServletResponse response)
+            throws Exception {
+        return (ModelAndView) method.invoke(handler, request, response);
     }
 }

study/src/main/java/servlet/com/example/CharacterEncodingFilter.java

@@ -4,13 +4,15 @@
 import jakarta.servlet.annotation.WebFilter;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 
 @WebFilter("/*")
 public class CharacterEncodingFilter implements Filter {
 
     @Override
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
         request.getServletContext().log("doFilter() 호출");
+        response.setCharacterEncoding(StandardCharsets.UTF_8.name());
         chain.doFilter(request, response);
     }
 }

study/src/test/java/reflection/Junit3TestRunner.java

@@ -1,13 +1,21 @@
 package reflection;
 
+import com.sun.nio.sctp.PeerAddressChangeNotification.AddressChangeEvent;
+import java.lang.reflect.Method;
 import org.junit.jupiter.api.Test;
 
 class Junit3TestRunner {
 
     @Test
     void run() throws Exception {
         Class<Junit3Test> clazz = Junit3Test.class;
-
+        final var junit3 = (Junit3Test) clazz.getConstructor().newInstance();
+
         // TODO Junit3Test에서 test로 시작하는 메소드 실행
+        for (final Method method : clazz.getDeclaredMethods()) {
+            if (method.getName().startsWith("test")) {
+                method.invoke(junit3);
+            }
+        }
     }
 }

study/src/test/java/reflection/Junit4TestRunner.java

@@ -1,5 +1,7 @@
 package reflection;
 
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
 import org.junit.jupiter.api.Test;
 
 class Junit4TestRunner {
@@ -9,5 +11,12 @@ void run() throws Exception {
         Class<Junit4Test> clazz = Junit4Test.class;
 
         // TODO Junit4Test에서 @MyTest 애노테이션이 있는 메소드 실행
+        Junit4Test junit4Test = clazz.getConstructor().newInstance();
+        Method[] methods = clazz.getDeclaredMethods();
+        for (final Method method : methods) {
+            if (method.isAnnotationPresent(MyTest.class)) {
+                method.invoke(junit4Test);
+            }
+        }
     }
 }

study/src/test/java/reflection/ReflectionTest.java

@@ -1,5 +1,8 @@
 package reflection;
 
+import java.util.Arrays;
+import java.util.Date;
+import java.util.stream.Collectors;
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -19,34 +22,38 @@ class ReflectionTest {
     void givenObject_whenGetsClassName_thenCorrect() {
         final Class<Question> clazz = Question.class;
 
-        assertThat(clazz.getSimpleName()).isEqualTo("");
-        assertThat(clazz.getName()).isEqualTo("");
-        assertThat(clazz.getCanonicalName()).isEqualTo("");
+        assertThat(clazz.getSimpleName()).isEqualTo("Question");
+        assertThat(clazz.getName()).isEqualTo("reflection.Question");
+        assertThat(clazz.getCanonicalName()).isEqualTo("reflection.Question");
     }
 
     @Test
     void givenClassName_whenCreatesObject_thenCorrect() throws ClassNotFoundException {
         final Class<?> clazz = Class.forName("reflection.Question");
 
-        assertThat(clazz.getSimpleName()).isEqualTo("");
-        assertThat(clazz.getName()).isEqualTo("");
-        assertThat(clazz.getCanonicalName()).isEqualTo("");
+        assertThat(clazz.getSimpleName()).isEqualTo("Question");
+        assertThat(clazz.getName()).isEqualTo("reflection.Question");
+        assertThat(clazz.getCanonicalName()).isEqualTo("reflection.Question");
     }
 
     @Test
     void givenObject_whenGetsFieldNamesAtRuntime_thenCorrect() {
         final Object student = new Student();
-        final Field[] fields = null;
-        final List<String> actualFieldNames = null;
+        final Field[] fields = student.getClass().getDeclaredFields();
+        final List<String> actualFieldNames = Arrays.stream(fields)
+                .map(Field::getName)
+                .collect(Collectors.toList());
 
         assertThat(actualFieldNames).contains("name", "age");
     }
 
     @Test
     void givenClass_whenGetsMethods_thenCorrect() {
         final Class<?> animalClass = Student.class;
-        final Method[] methods = null;
-        final List<String> actualMethods = null;
+        final Method[] methods = animalClass.getDeclaredMethods();
+        final List<String> actualMethods = Arrays.stream(methods)
+                .map(Method::getName)
+                .collect(Collectors.toList());
 
         assertThat(actualMethods)
                 .hasSize(3)
@@ -56,7 +63,7 @@ void givenClass_whenGetsMethods_thenCorrect() {
     @Test
     void givenClass_whenGetsAllConstructors_thenCorrect() {
         final Class<?> questionClass = Question.class;
-        final Constructor<?>[] constructors = null;
+        final Constructor<?>[] constructors = questionClass.getConstructors();
 
         assertThat(constructors).hasSize(2);
     }
@@ -65,11 +72,11 @@ void givenClass_whenGetsAllConstructors_thenCorrect() {
     void givenClass_whenInstantiatesObjectsAtRuntime_thenCorrect() throws Exception {
         final Class<?> questionClass = Question.class;
 
-        final Constructor<?> firstConstructor = null;
-        final Constructor<?> secondConstructor = null;
+        final Constructor<?> firstConstructor = questionClass.getConstructors()[0];
+        final Constructor<?> secondConstructor = questionClass.getConstructors()[1];
 
-        final Question firstQuestion = null;
-        final Question secondQuestion = null;
+        final Question firstQuestion = (Question) firstConstructor.newInstance("gugu", "제목1", "내용1");
+        final Question secondQuestion = (Question) secondConstructor.newInstance(0, "gugu", "제목2", "내용2", new Date(), 0);
 
         assertThat(firstQuestion.getWriter()).isEqualTo("gugu");
         assertThat(firstQuestion.getTitle()).isEqualTo("제목1");
@@ -82,15 +89,15 @@ void givenClass_whenInstantiatesObjectsAtRuntime_thenCorrect() throws Exception
     @Test
     void givenClass_whenGetsPublicFields_thenCorrect() {
         final Class<?> questionClass = Question.class;
-        final Field[] fields = null;
+        final Field[] fields = questionClass.getFields();
 
         assertThat(fields).hasSize(0);
     }
 
     @Test
     void givenClass_whenGetsDeclaredFields_thenCorrect() {
         final Class<?> questionClass = Question.class;
-        final Field[] fields = null;
+        final Field[] fields = questionClass.getDeclaredFields();
 
         assertThat(fields).hasSize(6);
         assertThat(fields[0].getName()).isEqualTo("questionId");
@@ -99,31 +106,32 @@ void givenClass_whenGetsDeclaredFields_thenCorrect() {
     @Test
     void givenClass_whenGetsFieldsByName_thenCorrect() throws Exception {
         final Class<?> questionClass = Question.class;
-        final Field field = null;
+        final Field field = questionClass.getDeclaredField("questionId");
 
         assertThat(field.getName()).isEqualTo("questionId");
     }
 
     @Test
     void givenClassField_whenGetsType_thenCorrect() throws Exception {
         final Field field = Question.class.getDeclaredField("questionId");
-        final Class<?> fieldClass = null;
+        final Class<?> fieldClass = field.getType();
 
         assertThat(fieldClass.getSimpleName()).isEqualTo("long");
     }
 
     @Test
     void givenClassField_whenSetsAndGetsValue_thenCorrect() throws Exception {
         final Class<?> studentClass = Student.class;
-        final Student student = null;
-        final Field field = null;
+        final Student student = (Student) studentClass.getConstructor().newInstance();
+        final Field field = studentClass.getDeclaredField("age");
 
         // todo field에 접근 할 수 있도록 만든다.
+        field.setAccessible(true);
 
         assertThat(field.getInt(student)).isZero();
         assertThat(student.getAge()).isZero();
 
-        field.set(null, null);
+        field.set(student, 99);
 
         assertThat(field.getInt(student)).isEqualTo(99);
         assertThat(student.getAge()).isEqualTo(99);

study/src/test/java/reflection/ReflectionsTest.java

@@ -1,9 +1,14 @@
 package reflection;
 
+import java.util.Set;
+import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
 import org.reflections.Reflections;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import reflection.annotation.Controller;
+import reflection.annotation.Repository;
+import reflection.annotation.Service;
 
 class ReflectionsTest {
 
@@ -14,5 +19,12 @@ void showAnnotationClass() throws Exception {
         Reflections reflections = new Reflections("reflection.examples");
 
         // TODO 클래스 레벨에 @Controller, @Service, @Repository 애노테이션이 설정되어 모든 클래스 찾아 로그로 출력한다.
+        Set<Class<?>> controllerClasses = reflections.getTypesAnnotatedWith(Controller.class);
+        Set<Class<?>> serviceClasses = reflections.getTypesAnnotatedWith(Service.class);
+        Set<Class<?>> repositoryClasses = reflections.getTypesAnnotatedWith(Repository.class);
+
+        Stream.of(controllerClasses, serviceClasses, repositoryClasses)
+                .flatMap(Set::stream)
+                .forEach(clazz -> log.info(clazz.getName()));
     }
 }

study/src/test/java/servlet/com/example/ServletTest.java

@@ -28,7 +28,8 @@ void testSharedCounter() {
 
         // expected를 0이 아닌 올바른 값으로 바꿔보자.
         // 예상한 결과가 나왔는가? 왜 이런 결과가 나왔을까?
-        assertThat(Integer.parseInt(response.body())).isEqualTo(0);
+        // 인스턴스 변수가 공유되어 같은 변수에 접근하여 body의 값이 3번 증가하여 3이 된다.
+        assertThat(Integer.parseInt(response.body())).isEqualTo(3);
     }
 
     @Test
@@ -50,6 +51,7 @@ void testLocalCounter() {
 
         // expected를 0이 아닌 올바른 값으로 바꿔보자.
         // 예상한 결과가 나왔는가? 왜 이런 결과가 나왔을까?
-        assertThat(Integer.parseInt(response.body())).isEqualTo(0);
+        // 메서드가 종료되면 stack 영역에 있는 지역 변수가 해제되기 때문
+        assertThat(Integer.parseInt(response.body())).isEqualTo(1);
     }
 }