리뷰 빠르게 반영해주셨네요! 테스트가 없어서 아쉽네요, 추후에 꼭 추가해주세요! 고생하셨습니다~

리뷰 빠르게 반영해주셨네요!
테스트가 없어서 아쉽네요, 추후에 꼭 추가해주세요! 고생하셨습니다~

study/src/main/java/cache/com/example/cachecontrol/CacheWebConfig.java

@@ -1,13 +1,22 @@
 package cache.com.example.cachecontrol;
 
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.CacheControl;
 import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import org.springframework.web.servlet.mvc.WebContentInterceptor;
 
 @Configuration
 public class CacheWebConfig implements WebMvcConfigurer {
 
     @Override
     public void addInterceptors(final InterceptorRegistry registry) {
+        final CacheControl cacheControl = CacheControl.noCache()
+                .cachePrivate();
+
+        final WebContentInterceptor webContentInterceptor = new WebContentInterceptor();
+        webContentInterceptor.addCacheMapping(cacheControl, "/**");
+
+        registry.addInterceptor(webContentInterceptor);
     }
 }

study/src/main/java/cache/com/example/etag/EtagFilterConfiguration.java

@@ -1,12 +1,18 @@
 package cache.com.example.etag;
 
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.filter.ShallowEtagHeaderFilter;
 
 @Configuration
 public class EtagFilterConfiguration {
 
-//    @Bean
-//    public FilterRegistrationBean<ShallowEtagHeaderFilter> shallowEtagHeaderFilter() {
-//        return null;
-//    }
+    @Bean
+    public FilterRegistrationBean<ShallowEtagHeaderFilter> shallowEtagHeaderFilter() {
+        final FilterRegistrationBean<ShallowEtagHeaderFilter> filterRegistrationBean = new FilterRegistrationBean<>(new ShallowEtagHeaderFilter());
+        filterRegistrationBean.addUrlPatterns("/etag");
+        filterRegistrationBean.addUrlPatterns("/resources/*");
+        return filterRegistrationBean;
+    }
 }

study/src/main/java/cache/com/example/version/CacheBustingWebConfig.java

@@ -2,8 +2,10 @@
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.CacheControl;
 import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+import java.util.concurrent.TimeUnit;
 
 @Configuration
 public class CacheBustingWebConfig implements WebMvcConfigurer {
@@ -13,13 +15,14 @@ public class CacheBustingWebConfig implements WebMvcConfigurer {
     private final ResourceVersion version;
 
     @Autowired
-    public CacheBustingWebConfig(ResourceVersion version) {
+    public CacheBustingWebConfig(final ResourceVersion version) {
         this.version = version;
     }
 
     @Override
     public void addResourceHandlers(final ResourceHandlerRegistry registry) {
         registry.addResourceHandler(PREFIX_STATIC_RESOURCES + "/" + version.getVersion() + "/**")
-                .addResourceLocations("classpath:/static/");
+                .addResourceLocations("classpath:/static/")
+                .setCacheControl(CacheControl.maxAge(365, TimeUnit.DAYS).cachePublic());
     }
 }

study/src/main/resources/application.yml

@@ -3,7 +3,11 @@ handlebars:
 
 server:
   tomcat:
-    accept-count: 1
-    max-connections: 1
+    accept-count: 10
+    max-connections: 2
     threads:
-      max: 2
+      max: 10
+
+  compression:
+    enabled: true
+    min-response-size: 10

study/src/test/java/thread/stage0/SynchronizationTest.java

@@ -1,18 +1,17 @@
 package thread.stage0;
 
-import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.assertThat;
 
+import org.junit.jupiter.api.Test;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 /**
  * 다중 스레드 환경에서 두 개 이상의 스레드가 변경 가능한(mutable) 공유 데이터를 동시에 업데이트하면 경쟁 조건(race condition)이 발생한다.
  * 자바는 공유 데이터에 대한 스레드 접근을 동기화(synchronization)하여 경쟁 조건을 방지한다.
  * 동기화된 블록은 하나의 스레드만 접근하여 실행할 수 있다.
- *
+ * <p>
  * Synchronization
  * https://docs.oracle.com/javase/tutorial/essential/concurrency/sync.html
  */
@@ -21,14 +20,14 @@ class SynchronizationTest {
     /**
      * 테스트가 성공하도록 SynchronizedMethods 클래스에 동기화를 적용해보자.
      * synchronized 키워드에 대하여 찾아보고 적용하면 된다.
-     *
+     * <p>
      * Guide to the Synchronized Keyword in Java
      * https://www.baeldung.com/java-synchronized
      */
     @Test
     void testSynchronized() throws InterruptedException {
-        var executorService = Executors.newFixedThreadPool(3);
-        var synchronizedMethods = new SynchronizedMethods();
+        final var executorService = Executors.newFixedThreadPool(3);
+        final var synchronizedMethods = new SynchronizedMethods();
 
         IntStream.range(0, 1000)
                 .forEach(count -> executorService.submit(synchronizedMethods::calculate));
@@ -41,15 +40,15 @@ private static final class SynchronizedMethods {
 
         private int sum = 0;
 
-        public void calculate() {
+        public synchronized void calculate() {
             setSum(getSum() + 1);
         }
 
         public int getSum() {
             return sum;
         }
 
-        public void setSum(int sum) {
+        public void setSum(final int sum) {
             this.sum = sum;
         }
     }

study/src/test/java/thread/stage0/ThreadPoolsTest.java

@@ -1,21 +1,20 @@
 package thread.stage0;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 import org.junit.jupiter.api.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import java.util.concurrent.Executors;
 import java.util.concurrent.ThreadPoolExecutor;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
 /**
  * 스레드 풀은 무엇이고 어떻게 동작할까?
  * 테스트를 통과시키고 왜 해당 결과가 나왔는지 생각해보자.
- *
+ * <p>
  * Thread Pools
  * https://docs.oracle.com/javase/tutorial/essential/concurrency/pools.html
- *
+ * <p>
  * Introduction to Thread Pools in Java
  * https://www.baeldung.com/thread-pool-java-and-guava
  */
@@ -31,8 +30,8 @@ void testNewFixedThreadPool() {
         executor.submit(logWithSleep("hello fixed thread pools"));
 
         // 올바른 값으로 바꿔서 테스트를 통과시키자.
-        final int expectedPoolSize = 0;
-        final int expectedQueueSize = 0;
+        final int expectedPoolSize = 2;
+        final int expectedQueueSize = 1;
 
         assertThat(expectedPoolSize).isEqualTo(executor.getPoolSize());
         assertThat(expectedQueueSize).isEqualTo(executor.getQueue().size());
@@ -46,7 +45,7 @@ void testNewCachedThreadPool() {
         executor.submit(logWithSleep("hello cached thread pools"));
 
         // 올바른 값으로 바꿔서 테스트를 통과시키자.
-        final int expectedPoolSize = 0;
+        final int expectedPoolSize = 3;
         final int expectedQueueSize = 0;
 
         assertThat(expectedPoolSize).isEqualTo(executor.getPoolSize());
@@ -57,7 +56,7 @@ private Runnable logWithSleep(final String message) {
         return () -> {
             try {
                 Thread.sleep(1000);
-            } catch (InterruptedException e) {
+            } catch (final InterruptedException e) {
                 throw new RuntimeException(e);
             }
             log.info(message);

study/src/test/java/thread/stage1/ConcurrencyTest.java

@@ -1,17 +1,17 @@
 package thread.stage1;
 
-import org.junit.jupiter.api.Test;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * 스레드를 다룰 때 어떤 상황을 조심해야 할까?
  * - 상태를 가진 한 객체를 여러 스레드에서 동시에 접근할 경우
  * - static 변수를 가진 객체를 여러 스레드에서 동시에 접근할 경우
- *
+ * <p>
  * 위 경우는 동기화(synchronization)를 적용시키거나 객체가 상태를 갖지 않도록 한다.
  * 객체를 불변 객체로 만드는 방법도 있다.
- *
+ * <p>
  * 웹서버는 여러 사용자가 동시에 접속을 시도하기 때문에 동시성 이슈가 생길 수 있다.
  * 어떤 사례가 있는지 아래 테스트 코드를 통해 알아보자.
  */

tomcat/src/main/java/nextstep/Application.java

@@ -1,29 +1,11 @@
 package nextstep;
 
-import nextstep.jwp.HandlerResolver;
-import nextstep.jwp.JwpHttpDispatcher;
-import nextstep.jwp.SessionManager;
-import nextstep.jwp.handler.get.LoginGetHandler;
-import nextstep.jwp.handler.get.RegisterGetHandler;
-import nextstep.jwp.handler.get.RootGetHandler;
-import nextstep.jwp.handler.post.LoginPostHandler;
-import nextstep.jwp.handler.post.RegisterPostHandler;
 import org.apache.catalina.startup.Tomcat;
-import org.apache.coyote.http11.Handler;
-import java.util.Map;
 
 public class Application {
 
-    private static final Map<String, Handler> httpGetHandlers =
-            Map.of("/", new RootGetHandler(),
-                    "/login", new LoginGetHandler(new SessionManager()),
-                    "/register", new RegisterGetHandler());
-    private static final Map<String, Handler> httpPostHandlers =
-            Map.of("/login", new LoginPostHandler(new SessionManager()),
-                    "/register", new RegisterPostHandler());
-
     public static void main(final String[] args) {
-        final var tomcat = new Tomcat(new JwpHttpDispatcher(new HandlerResolver(httpGetHandlers, httpPostHandlers)));
+        final var tomcat = new Tomcat();
         tomcat.start();
     }
 }

tomcat/src/main/java/nextstep/jwp/DispatcherServlet.java

@@ -0,0 +1,29 @@
+package nextstep.jwp;
+
+import nextstep.jwp.controller.Controller;
+import org.apache.coyote.http11.ContentType;
+import org.apache.coyote.http11.HttpServlet;
+import org.apache.coyote.http11.StatusCode;
+import org.apache.coyote.http11.request.HttpRequest;
+import org.apache.coyote.http11.response.HttpResponse;
+
+public class DispatcherServlet implements HttpServlet {
+
+    private static final HandlerMapping handlerMapping = new HandlerMapping();
+
+    @Override
+    public void service(final HttpRequest httpRequest, final HttpResponse httpResponse) {
+        final Controller controller = handlerMapping.findController(httpRequest.getPath());
+        if (controller == null) {
+            generateNotFoundController(httpResponse);
+            return;
+        }
+        controller.service(httpRequest, httpResponse);
+    }
+
+    private void generateNotFoundController(final HttpResponse response) {
+        response.setStatusCode(StatusCode.NOT_FOUND)
+                .setContentType(ContentType.HTML)
+                .setRedirect("/404.html");
+    }
+}

tomcat/src/main/java/nextstep/jwp/HandlerMapping.java

@@ -0,0 +1,19 @@
+package nextstep.jwp;
+
+import nextstep.jwp.controller.Controller;
+import nextstep.jwp.controller.LoginController;
+import nextstep.jwp.controller.RegisterController;
+import nextstep.jwp.controller.RootGetController;
+import java.util.Map;
+
+public class HandlerMapping {
+
+    private static final Map<String, Controller> controllers =
+            Map.of("/", new RootGetController(),
+                    "/login", new LoginController(),
+                    "/register", new RegisterController());
+
+    public Controller findController(final String path) {
+        return controllers.get(path);
+    }
+}